Midlands Astronomy Club Magazine
Sky Guide - Beginner’s targets for December The good news in December is that it gets dark nice and early allowing for long observing sessions. The bad news for those of us in the North is that the price we pay for the early evenings is the cold that accompanies it. So, fill your thermos with some nice hot coffee or hot chocolate and enjoy the wonderful winter skies. We'll start off again this month naked eye. The Geminid Meteor Shower peaks on the 13th. This is usually one of the best meteor showers of the year and should offer excellent viewing this year as the moon is in good position (waning crescent). The Geminids will seem to radiate from a point near the stars Castor and Pollux. Castor and Pollux are to the upper right of the famed Betelgeuse in Orion. Watch this area of the sky from a dark site and you can expect to see as many as 60 - 80 meteors an hour. Telescope Targets December continues to offer wonderful views of Cassiopea, Andromeda, Auriga and Perseus. See October's and November's picks pages for targets in these constellations. The Pleiades (M45) or also known as the Seven Sisters is a wonderful low power open cluster in the constellation Taurus. It is among the nearest star clusters, and is
Issue 19 - December, 2010
probably the best known, and is certainly the most obvious to the naked eye. It is easily identified high in the Southeast early after sunset. Look for 6 stars that appear to be a miniature version of the big dipper. Point your telescope with it's lowest power eyepiece at this and you'll be shocked at how many stars are visible. They are located at a distance of 400 light years from us and contain 100 stars. This cluster is approximately 78 million years old. Also in the same area of sky are the Hyades. This is one of those targets best seen with binoculars. The Hyades are a huge open cluster of 350 stars located at a distance of 150 Light years from us. The Hyades are below the Pleiades. Look for the "V" shaped grouping of stars and point your binoculars or your telescope toward them. The Hyades hold the distinction of being the closest open cluster to us.
Taurus is one of the constellations of the zodiac. It sits large and prominent in the Northern Hemisphere winter sky, between Aries to the west and Gemini to the east; to the north lie Perseus and Auriga, to the southeast Orion, to the south Eridanus, and to the southwest Cetus. Behind the star Aldebaran lie the Hyades, the nearest distinct open star cluster, that with it form a V, or an A, in the sky marking the bull's head. In the west of the constellation lie the Pleiades, one of the best known open clusters, easily visible to the eye. Another object, visible in a telescope, is the Crab Nebula (M1), a supernova remnant northwest of Îś Tauri. The explosion, seen on Earth on July 4, 1054, was bright enough to be seen by day. It is mentioned in Chinese history texts.
Well, that's about it for this month. Orion is rising in the south and will offer lots of targets for late evening this month also. I will detail these in January's picks.
Clear skies and good hunting!
By Kevin Daly http://members.aol.com/kdaly10475/index.html
Planets Jupiter is in excellent position for viewing right after sunset positioned high in the southern sky. Saturn is also in great position for viewing in the Southeast in the early evening. Show some family or friends this superstar of the sky.
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Club Notes Club Observing: Remember the next club meets every first Friday of the month for our observing sessions held in the MAC grounds. If you wish to be informed of these sessions please email your name and mobile number to midlandsastronomy@gmail.com who will confirm if the session is going ahead (depending on weather).
Kids Astronomy
MAC is a proud member of The Pleiades cluster is dominated by hot blue stars that have formed within the last 100 million years. Dust that forms a faint reflection nebulosity around the brightest stars was thought at first to be left over from the formation of the cluster, but is now known to be an unrelated dust cloud in the interstellar medium that the stars are currently passing through. Astronomers estimate that the cluster will survive for about another 250 million years, after which it will disperse due to gravitational interactions with its galactic neighbourhood.
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Quizzes and Games Monthly Sky Guide
Midlands Astronomy Club Magazine
Galaxy Zoo: The hunt for supernovae ................................... 8 Fermi telescope finds giant structure in the Milky Way ........... 9
Front cover image: Spooky shapes seem to haunt this starry expanse, drifting through the night in the royal constellation Cepheus. Of course, the shapes are cosmic dust clouds faintly visible in dimly reflected starlight. Far from your own neighbourhood on planet Earth, they lurk at the edge of the Cepheus Flare molecular cloud complex some 1,200 light-years away. Over 2 light-years across the ghostly nebula known as vdB 141 or Sh2-136 is near the centre of the field. The core of the dark cloud on the right is collapsing and is likely a binary star system in the early stages of formation.
Upcoming flybys could provide clues to interior of Enceladus ....................................................................... 9
Kids Section Kids Korner ....................................................................... 10
Quizzes and Games Exercise your brain ............................................................ 11
Monthly Sky Guide Beginners sky guide for December ..................................... 12
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4. The smaller, Earth-like planets are called 'terrestrial' planets. What are the larger planets called? Saturnine Jovian Torrential Uranian 5. Which moon of Saturn is one of the only two moons in the solar system with an atmosphere? Titan Io Triton Charon
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9. The galaxy known as IRAS F10214+4724 is how many times brighter than the sun? 500 7,000 5,000 300,000,000,000,000 10.What was the name of the comet that made its closest approach to Earth on March 22, 1997? Hale-Bopp Encke's comet Halley's comet Herschel's comet
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8. What is it called when we have a second full moon within one month? Blue moon New moon Full moon To the moon Alice!
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Check your answers
Answer 1: Plasma is usually an ionized gas, meaning that one electron has been taken or added to an accumulation of atoms or molecules.
Dissolving star systems create mess in Orion ........................ 7
White layers of clouds on Jupiter The division of the large and small planets Space between the asteroids and Mars A gap in Saturn's rings
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Answer 6: The correct answer was Southern Cross. The 'crux' of this matter is that you can only see the Southern Cross in the sky if you live in the southern hemisphere...it's worth the trip (unless you already live there, then no trip is needed of course!)
Saturn's weird moon, Pan .................................................... 7
3. What in our solar system is the Cassini Division?
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Answer 2: Edwin Hubble was a great American astronomer from the early 20th century. One of his major discoveries was to ascertain with proof that there are other galaxies outside the Milky Way.
How Jupiter is getting its belt back ....................................... 6
Great and little dog Big and little dipper Orion and his dog Big and little lion
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Answer 7: The 3 stars in the bow that makes up the handle of the Big Dipper direct ones eye toward the North Star, Polaris. Polaris lies at the tip of the Little Dipper's handle. By the way, the term 'Ursa' is Latin for 'bear'...the great and small bear.
Alien worlds observed in Galaxies beyond Milky Way ............. 5
Mercutio Galileo Edwin Isaac
7. P o r t i o n s of the constellations Ursa Major and Ursa Minor are also known as what?
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Answer 8: The correct answer was Blue moon. I will leave this one to your imagination, as I hum the tune 'Blue Moon'...
The Sun steals Comets from other Stars ............................... 5
2. We have all heard of the Hubble space telescope. What was the first name of the astronomer with the last name Hubble?
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Answer 3: Gioovanni Domenico Cassini was an Italian-French astronomer from the late 17th-early 18th century. He followed up on Galileo's work with a more powerful telescope, one that allowed him to discover four moons of Saturn and the gaps in Saturn's rings that bear his name.
You can see more about the club and its events on www.midlandsastronomy.com or contact the club via e-mail at tullamoreastronomy@yahoo.co.uk. Meetings are informal and are aimed at a level to suit all ages.
Tenuous Oxygen atmosphere found around Saturn’s moon Rhea ......................................................................... 4
Northern Crown Northern Cross Southern Cross Southern Crown
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Answer 9: The correct answer was 300,000,000,000,000. Do not, I repeat, do not look at this galaxy with your naked eye. Well, actually from Earth you would have no problem...you see, it's millions of light years away from us and barely visible with the naked eye.
ISS Celebrates 10 Years of Human Habitation ....................... 3
Gas Plasma Solid Liquid
SUDOKU
6. The constellation 'Crux' is probably better known as what?
Answer 4: The 'terrestrial' planets are so named because they have hard, rocky surfaces like the Earth...terra firma. The Jovian planets are named for Jupiter, the king of the Roman gods and the largest planet. They are also called the 'gas giants'.
"Limits of Organic Life": NASA to Search for 'Weird' Non-Carbon-Based Life ........................................................ 3
1. What state of matter is our Sun mainly consisted of?
Answer 10: Not coincidentally, the Hale -Bopp comet was discovered by a pair of scientists with the last names 'Hale' and 'Bopp'!
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All are welcome to attend. It also holds infrequent Observing Nights at its Observing Site in Clonminch, or at a member’s house (weather permitting) on the first Friday of every month..
Exercise your brain
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Answer 5: Titan is though to have its own atmosphere, it is not the largest moon in the solar system. That title belongs to Jupiter's moon Ganymede! Triton, a moon of Neptune, also has a thin but viable atmosphere.
MAC meets on the first Tuesday of the month in the Presbyterian Hall, High Street, Tullamore from 8pm.
Midlands Astronomy Club Magazine
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Midlands Astronomy Club Magazine
Kid’s Korner Do constellations ever break apart ever or change? Our friends at the Cable Natural History Museum in Cable, Wisconsin, ask whether constellations ever break apart or change. To answer this, first let's think about what the constellations are, and then we can see whether they change. When we look at the night sky, we see distant stars shining like faint lights. Now we know they are really brilliant lights, like the Sun, that are incredibly far away from us and from each other. Astronomers have used some wonderfully inventive methods to discover the distances to the stars, but to our eyes, they all look as if they are pinpoints of light at the same distance. As an extreme example of this, the red planet Mars is tens of millions of times closer than the red star Antares (Greek for "Rival of Mars"), but you certainly can't tell that just by looking at them when they appear near each other in our skies.
of the nature of stars and space, saw these patterns and thought they might be important symbols. Cultures throughout history have created different names and descriptions for the arrangements of stars. The constellations most of us are familiar with were created by people living in the Mediterranean and the Middle East. Many of the stories of the constellations tell us about the myths and legends of the people who gave them names thousands of years ago, but they tell us nothing about the stars themselves.
If stars never changed, then constellations wouldn't change. But the stars, including the Sun, travel in their own separate orbits through the Milky Way galaxy. The stars move along with fantastic speeds, but they are so far away that it takes a It's normal for us to find patterns in long time for natural arrangements of things. For their motion to example, most people can imagine they see faces or other familiar objects in some clouds or rock formations. It's the same with the stars. Ancient observers, without the benefit of our m o d e r n understanding
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be visible to us. You can understand this by moving your finger in front of your eyes. Even when you move it very slowly, it may appear to move faster than a speeding jet that is many miles away. Even the fastest stars take a long time to travel a noticeable distance. A faint star named Barnard's Star moves the fastest through our skies. Still, for it to change its position only by an amount equal to the width of the moon would take about 180 years. The constellations surely change shape, but seeing the changes would require superhuman patience!
Midlands Astronomy Club Magazine was enough for Halley to realize that those stars must have moved. If you waited long enough, the patterns of stars you would see in the sky would change completely. The Big Dipper is the easily recognizable part of a constellation called Ursa Major, or the Great Bear. The star at the end of the handle and the one at the far tip of the bowl happen to be moving in the opposite direction from the other stars in the Big Dipper. In the future, the handle will appear to be more bent, and the bowl will spread out. To me, the shape in 5 0 , 00 0
years will be more like that of a tadpole than a dipper. Be s id e s th e i r m o t io n, t he appearances of stars change as they age. Take my favourite constellation Scorpius, for example. A couple of years ago, the middle of the three stars that make the head of the scorpion became brighter. The constellation now has a new look! The constellations are a very convenient way to locate objects in the splendid night sky, making a kind of natural map. If you knew the names of the constellations, you could follow directions to all sorts of beautiful and interesting objects, just as if you knew the names of streets, you could follow directions on how to get to a friend's house.
The person who discovered that the stars move was the great British astronomer Edmond Halley, who also has a famous comet named after him. Almost 300 years ago he noticed that a few stars in charts made by Greek sky watchers were not in quite the same location anymore. Those charts were more than 1600 years old then, and even over that time, the bright stars Sirius, Arcturus, and Aldebaran had shifted position only slightly. Still, it
To make your own star finder and learn some of the constellations, go to The Space Place Web site at spaceplace.nasa.gov and click on "Make spacey things." Then I hope you will go outside to look at the stars, and use the constellations to find your way around. Remember, though, that what's important is not these patterns themselves, but rather the richness of the universe they will help you discover.
"Limits of organic life": NASA to search for 'weird' non-carbon-based life The recent announcement by NASA of the discovery of the possibility of arsenic-based life in Mono Lake fits hand-in-glove with NASA's strategy to expand the search for life beyond Earth to extreme non-carbon-based life. No discovery that we can make in our exploration of the solar system would have greater impact on our view of our position in the cosmos, or be more inspiring, than the discovery of an alien life form, even a primitive microbial one. The discovery over the past decade of extreme life forms thriving on Earth at the super-heated walls of Ocean volcanic vents and in the interior regions of the planet's crust, led to a seminal 2009 report, The Limits of Organic Life in Planetary Systems, by the National Research Council (NRC). The NASA sponsored report recommended that the search for beyond Earth’s solar system
should be widened throughout the universe to include the possibility of “weird” life. "Nothing," the report concludes, "would be more tragic in the American exploration of space than
Above: An image GFAJ-1 grown on arsenic. Left: Felisa Wolfe-Simon processing mud from Mono Lake to inoculate media to grow microbes on arsenic.
Above: An image of Mono Lake Research area where the discovery of arsenicbased life has been discovered. to encounter alien life and fail to recognise it.” Earth did not accumulate oxygen during the first roughly 3 billion years, or form an ozone layer until about 1.5 billion years ago. There is considerable emphasis on looking for contemporary Earth atmospheres that have oxygen and an ozone layer, but, the report hits home, we should also be using models with different anaerobic microbial non-carbon ecosystems, atmospheres that might parallel the different stages in the evolution of Earth's atmospheres over 4 billion years, and conditions that could indicate the presence of a tectonically active planet. The report pointed out that the exploration of the planet is concentrated on looking for places
where liquid water exists—which goes along with the idea of where life is found on the Earth. However, they emphasize that liquids such as ammonia, methane, and formamide could also be the building blocks for life. Saturn's moon, Titan is a perfect candidate: the discovery of evidence of liquid water-ammonia on Titan provides the potential for life-bearing polar fluids outside what is normally regarded as the habitable zone. The stay of the Cassini-Huygens mission on the surface of Titan was unfortunately brief; but Titan is the locale that is likely to support exotic life, which could be discovered using robotic remote sensing devices. http://www.dailygalaxy.com
ISS Celebrates 10 Years of Human Habitation Last month the International Space Station has had a human crew since 2000. Ten years! Ten years, 200 inhabitants, 15 nations, 600 experiments and NASA's first robot space assistant signalling the beginning of the Age of Space Droids! An international outpost one official wag dubbed the "zero gravity United Nations." A rare and refreshing a symbol of international cooperation and worldwide unity. More than 200 orbiting explorers have visited the space complex; 15 nations have contributed to the missions, providing modules and hardware; and more than 600 experiments have been carried out on board. http://www.dailygalaxy.com
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Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Tenuous Oxygen atmosphere found around Saturn’s moon Rhea A few years ago, astronomers thought they found wispy rings around Saturn’s moon Rhea. Although the possibility of rings around this icy moon was later nixed, astronomers knew there was still something around Rhea that was causing a strange, symmetrical structure in the charged-particle environment around Saturn’s second-largest moon. Now, new observations have shown something else around Rhea that was completely unexpected: an oxygen atmosphere. In March of this year, the Cassini spacecraft made a close flyby of Rhea and recorded data showing a thin atmosphere made up of oxygen and carbon dioxide. The source of the oxygen is not really a surprise: Rhea’s density of 1.233 times that of liquid water suggests that Rhea is three quarters ice and one quarter rock. The moon’s tenuous atmosphere is maintained by the on going chemical decomposition of ice water on the moon’s surface by irradiation from Saturn’s magnetosphere. Oxygen has also recently been detected in the atmospheres of two of Jupiter’s moons, Europa and Ganymede. Since oxygen is a main
component of the atmosphere surrounding Satur n’s ring s, astronomers think there could be similar atmospheres around other icy moons that orbit inside Saturn’s magnetosphere. “The new results suggest that active, complex chemistry involving oxygen may be quite common throughout the solar system and even our universe,” said lead author Ben Teolis, a Cassini team scientist. “Such chemistry could be a prerequisite for life. All evidence from Cassini indicates that Rhea is too cold and devoid of the liquid water necessary for life as we know it.”
Fermi telescope finds giant structure in the Milky Way
Of course, there’s always the possibility of life as we don’t know it. And, there must be s om e s or t of organics on the moon – meaning carbon compounds. The source of the carbon dioxide in Rhea’s atmosphere is not yet known, but its presence Above: Rhea, as seen by Cassini. Credit: NASA suggests that radiolysis reactions between oxidants and organics dioxide of around 20 billion are on going at the moon’s molecules per cubic meter. surface. The plasma spectrometer saw clear This latest data came from Cassini’s signatures of flowing streams of ion and neutral mass spectrometer positive and negative ions, with a n d t h e C a s s i n i p l a s m a masses that corresponded to ions spectrometer during flybys on Nov. of oxygen and carbon dioxide. The 26, 2005, Aug. 30, 2007, and oxygen appears to rise to an March 2, 2010. The ion and neutral a t m o s p h e r e w h e n S a t u r n’ s mass spectrometer saw peak magnetic field rotates over Rhea. densities of oxygen of around 50 Energetic particles trapped in the billion molecules per cubic meter. It planet‘s magnetic field pepper the detected peak densities of carbon moon’s water-ice surface. They cause chemical reactions that decompose the surface and release oxygen. Releasing oxygen through surface irradiation could help generate conditions favourable for life at an icy body other than Rhea that has liquid water under the surface. If the oxygen and carbon dioxide from the surface could somehow get transported down to a subsurface ocean, that would provide a much more hospitable environment for more complex compounds and life to form. The scientists are unsure how the carbon dioxide is released. It could be the result of “dry ice” trapped from the primordial solar nebula, as is the case with comets, or it may be due to similar irradiation processes operating on the organic molecules trapped in the water ice of Rhea. The carbon dioxide could also come from carbon-rich materials deposited by tiny meteors that bombarded Rhea’s surface.
Above: The 2 March 2010 Rhea flyby trajectory and simulated oxygen atmosphere distribution. Inset: Predicted oxygen density (yellow) compared to the INMS measurement (white) during the flyby.
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NASA’s Fermi Gamma-ray Space Telescope has unveiled a previously unseen structure centred in the Milky Way. The feature spans 50,000 light-years and may be the remnant of an eruption from a supersized black hole at the centre of our galaxy. “What we see are two gamma-rayemitting bubbles that extend 25,000 light-years north and south of the galactic centre,” said Doug Finkbeiner, an astronomer at the Harvard-Smithsonian Centre for Astrophysics, who first recognised the feature. “We don’t fully understand their nature or origin.” The structure spans more than half of the visible sky, from the c ons te lla tio n V ir g o to t he constellation Grus, and it may be millions of years old. A paper about the findings has been accepted for publication in The Astrophysical Journal. Scientists now are conducting more analyses to better understand how the never-before-seen structure was formed. The bubble emissions are much more energetic than the gamma-ray fog seen elsewhere in the Milky Way. The bubbles also appear to have well-defined edges. The s truc tur e’s s hape a nd
emissions suggest it was formed as a result of a large and relatively rapid energy release — the source of which remains a mystery. One possibility includes a particle jet from the supermassive black hole at the galactic centre. In many other galaxies, astronomers see fast particle jets powered by matter falling toward a central black hole. While there is no evidence the Milky Way’s black hole has such a jet today, it may have in the past. The bubbles also may have formed as a result of gas outflows from a burst of star formation, perhaps the one that produced many massive star clusters in the Milky Way’s centre several million years ago. “In other galaxies, we see that starbursts can drive enormous gas outflows,” said David Spergel, a scientist at Princeton University. “Whatever the energy source behind these huge bubbles may
Upcoming flybys could provide clues to interior of Enceladus What is going on inside Saturn’s moon Enceladus and what powers the icy geysers and jets? A pair of upcoming flybys by the Cassini spacecraft could help answer those questions. Radio instruments on board will measure the gravity field of Enceladus and focus particularly on the very intriguing south polar hot spot.
Above: At least four distinct plumes of water ice spew out from the south polar region of Saturn's moon Enceladus. Credit: NASA/JPL/Space Science Institute
Of course, the success of these flybys hinges on the Cassini mission controllers being able to wake up the dormant spacecraft which has been in safe mode since November 2. Teams will attempt to
Above: From end to end, the newly discovered gamma-ray bubbles extend 50,000 light-years, or roughly half of the Milky Way's diameter, as shown in this illustration. Credit: NASA be, it is connected to many deep questions in astrophysics.”
in France, Germany, Italy, Japan, Sweden and the United States.
“Fermi scans the entire sky every three hours, and as the mission continues and our exposure deepens, we see the extreme universe in progressively greater detail,” said Julie McEnery, Fermi project scientist at NASA’s Goddard Space Flight Centre. NASA’s Fermi is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners
“Since its launch in June 2008, Fermi repeatedly has proven itself to be a frontier facility, giving us new insights ranging from the nature of space-time to the first observations of a gamma-ray nova,” said Jon Morse, Astrophysics Division director at NASA. “These latest discoveries continue to demonstrate Fermi’s outstanding performance.”
get Cassini up and running again tomorrow, November 24, and they don’t anticipate any problems.
There will be two three-hour “wing” observations before and after closest-approach (from five to eight hours from closest approach on either side), and then three more hours cantered directly around closest approach. The Cassini team is throwing almost the entire gamut of instruments into the flyby program, between radio science (RSS) observations, the imaging science system (ISS) and composite infrared spectrometer (CIRS) which will observe this moon on the inbound leg, and CIRS and the visible and infrared mapping spectrometer (VIMS) which will take data on the outbound leg, with other optical remote sensing and fields, particles and waves instruments also taking data.
Cassini went into the protective standby mode and the likely cause of the problem was a faulty program code line, or a flipped bit in the spacecraft’s command and data system computer. The upcoming flybys of Enceladus will put Cassini very close – about 48 kilometres (30 miles) above the surface. The first will take place on November 30. Pairing this flyby with one on April 28, should provide scientists enough information to determine the nature of the interior right under the hot spot. The next flyby on December 21, Cassini will make 50-kilometer pass over the north pole of Enceladus. The fields and particles instruments will be trying to “sniff” anything coming from the moon.
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Midlands Astronomy Club Magazine
Aside from categorizing galaxies, another component of the Galaxy Zoo project has been asking participants to identify potential supernovae (SNe). The first results are out and have identified “nearly 14,000 supernova candidates from [Palomar Transient Factory, (PTF)] were classified by more than 2,500 individuals within a few hours of data collection.” Although the Galaxy Zoo project is the first to employ citizens as supernova spotters, the background programs have long been in place but were generating vast amounts of data to be processed. “The Supernova Legacy Survey used the MegaCam instrument on the 3.6m Canada-France-Hawaii Telescope to survey 4 deg2” every few days, in which “each square degree would typically generate ~200 candidates for each night of observation.” Additionallly, “the Sloan Digital Sky Survey-II Supernova Survey used the SDSS 2.5m telescope to survey a larger area of 300 deg2” and “human scanners viewed 30005000 objects each night spread over six scanners”. To ease this burden, the highly successful Galaxy Zoo implemented a Supernova Search in which users would be directed through a decision tree to help them determine what computer algorithms were proposing as transient events. Each image would be viewed and decided on by several participants increasing the likelihood of a correct appraisal. Also, “with a large number of people scanning candidates, more candidates can be examined in a shorter amount of time – and with the global Zooniverse (the parent project of Galaxy Zoo) user base this can be done around the clock, regardless of the local time zone the science team happens to be based in” allowing for “interesting candidates to be followed up on the same night as that of the SNe discovery, of particular interest to quickly evolving SNe or transient sources.” To identify candidates for viewing, images are taken using the 48 inch Samuel Oschin telescope at the Palomar Observatory. Images are the n c a lib r a te d to c or r ec t instrumental noise and compared
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automatically to reference images. Those in which an object appears with a change greater than five standard deviations from the general noise are flagged for inspection. While it may seem that this high threshold would eliminate other events, the Supernova Legacy Survey, starting with 200 candidates per night, would only end up identifying ~20 strong candidates. As such, nearly 90% of t h e s e c om p ut e r g e n e r a te d identifications were spurious, likely generated by cosmic rays striking the detector, objects within our own solar system, or other such nuisances and demonstrating the need for human analysis. Still, the PTF identifies between 300 and 500 candidates each night of operation. When exported to the Galaxy Zoo interface, users are presented with three images: The first is the old, reference image. The second is the recent image, and the third is the difference between the two, with brightness values subtracted pixel for pixel.
Sta r s w hic h d i d n’ t c ha n g e brightness would be subtracted to nothing, but those with a large change (such as a supernova), would register as a still noticeable star. Of course, this method is not flawless, which also contributes to the false positives from the computer system that the decision tree helps weed out. The first question (Is there a candidate cantered in the crosshairs of the right-hand [subtracted] image?) eliminates misprocessing by the algorithm due to misalignment. The second question (Has the candidate itself subtracted correctly?) serves to drop stars that were so bright, they saturated the CCD, causing odd errors often resulting in a “bullseye” pattern. Third (Is the candidate star-like and approximately circular?), users eliminate cosmic ray strikes which generally only fill one or two pixels or leave long trails (depending on the angle at which they strike the CCD). Lastly, users are asked if “the candidate centred in a circular host galaxy?” This sets aside identifications of variable stars within our own galaxy that are not events in other galaxies as well as supernovae that appear in the outskirts of their host galaxies.
Midlands Astronomy Club Magazine Each of these questions is assigned a number of positive or negative “points” to give an overall score for the identification. The higher the score, the more likely it is to be a true supernova. With the way the structure is set up, “candidates can only end up with a score of -1, 1 or 3 from each classification, with the most promising SN candidates scored 3.” If enough users rank an event with the appropriate score, the event is added to a daily subscription sent out to interested parties. To confirm the reliability of identifica tions, the top 20 candidates were followed up spectroscopically with the 4.2m William Herschel Telescope. Of them, 15 were confirmed as SNe, with 1 cataclysmic variable, and 4 remain unknown. When compared to followup observations from the PTF team, the Galaxy Zoo correctly identified 93% of supernova that were confirmed spectroscopically from them. Thus, the identification is strong and this large volume of known events will certainly help astronomers learn more about these events in the future. If you’d like to join, head over to their website and register. Presently, all supernovae candidates have been processed, but the next observing run is coming up soon!
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The Sun steals Comets from other Stars The next time you thrill at the sight of a comet blazing across the night sky, consider this: it's a stolen pleasure. You're enjoying the spectacle at the expense of a distant star. Sophisticated computer simulations run by researchers at the Southwest Research Institute (SWRI) have exposed the crime. "If the results are right, our Sun snatched comets from neighbouring stars' back yards," says SWRI scientist Hal Levison. And he believes this kind of thievery accounts for most of the comets in the Oort Cloud at the edge of our solar system. "We know that stars form in clusters. The Sun was born within a huge community of other stars that formed in the same gas cloud. In that birth cluster, the stars were close enough together to pull comets away from each other via gravity. It's like neighbourhood children playing in each others' back yards. It's hard to imagine it not happening." According to this "thief" model, comets accompanied the nearest star when the birth cluster blew apart. The Sun made off with quite a treasure – the Oort Cloud, which was swarming with comets fr om a ll over the "neighbourhood." The Oort cloud is an immense cloud of comets orbiting the Sun far beyond Pluto. It is named after mid -20th century Dutch astronomer Jan Oort, who first proposed such a cloud to explain the origin of comets sometimes seen falling into the inner solar system. Although no confirmed direct observations of the Oort cloud have been made, most astronomers believe that it is the source of all long-period and Halley -type comets. The standard model of comet production asserts that our Sun came by these comets honestly. "That model says the comets are dregs of our own solar system's planetary formation and that our planets gravitationally booted them
to huge distances, populating the cloud. But we believe this kind of scenario happened in all the solar systems before the birth cluster dispersed." Otherwise, says Levison, the numbers just don't add up. "The standard model can't produce anywhere near the number of comets we see falling in from the Oort Cloud. The Sun's sibling stars had to have contributed some comets." Comets in the Oort Cloud are typically 1 or 2 miles across, and they're so far away that estimating their numbers is no easy task. But Levison and his team say that, based on observations, that there should be something like 400
Above: Compared to the size of planetary orbits, the Oort cloud is very far away. Indeed, the estimated size of the Oort cloud is approximately 1 light year. If the Sun passed within 2 light years of another sun-like star, the stars' Oort clouds would overlap and their comets would intermingle. Image credit: ESO. billion comets there. The "domestic" model of comet formation can account for a population of only about 6 billion. "That's a pretty anemic Oort Cloud, and a huge discrepancy – too huge to be explained by mistakes in the estimates. There's no way we could be that far off, so there has to be something wrong with the model itself." He points to the cometary orbits as evidence. "These comets are in very odd orbits – highly eccentric long-period orbits that
take them far from our Sun, into remote regions of space. So they couldn't have been born in orbit around the Sun. They had to have formed close to other stars and then been hijacked here." This means comets can tell us not only about the early history of the Sun – but also about the history of other stars.
www.science.nasa.gov
Alien worlds observed in Galaxies beyond Milky Way With some 500 known exoplanet apparently all around us (galactically speaking), a global team of researchers have kicked it up a notch. Signals shining across millions of light years, from other galaxies, indicate the birth of solar systems - and we can see them. The work is based on spectroscopy, the science of examining what wavelengths of light come in and extracting all kinds of information from it (far more than our eyes, which just say "that's blue" and call it a day). Every material has a unique emission spectrum (very specific wavelengths they emit) and any intervening material absorbs it
(according to the same spectroscopic signature). This technique allows us to 'see' even when the light source is too faint or far away to make out detail any other way. The Spitzer Space Telescope and I nfr ar ed Spa c e Obs e r va tor y collected data from over eighty galaxies, and from these mindmeltingly far-flung light sources we can see spectroscopic signs of spawning solar systems. The received light (once adjusted for intergalactic red shift) shows three peaks: a huge spike for stellar material, a second peak from heated interstellar dust, and a faint third bump thought to result from circumstellar discs of material like the one that eventually formed us.
This is awesome science: as well as literally finding new worlds where no-one has gone before, we can use this new discovery as a (limited) window into the history of our own system. Discovering new things, and then using those to learn more new things.
www.dailygalaxy.com
www.midlandsastronomy.com Page - 5
Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
How Jupiter is getting its belt back
Saturn's weird moon, Pan Strange flying-saucer-shaped moons embedded in Saturn's rings have baffled scientists studying images transmitted by the ESA's Cassini Spacecraft. New research suggests that the oddly shaped moons, Pan and Atlas, are born largely from clumps of icy particles in the rings themselves, a discovery that could shed light on how Earth and other planets formed from the disk of matter that once surrounded our newborn sun.
Earlier this year, one of Jupiter’s stripes went missing. The Southern Equatorial Band started to get lighter and paler, and eventually disappeared. Now, follow-up images from both professional and amateur astronomers are showing some activity in the area of the SEB, and scientists now believe the vanished dark stripe is making a comeback. They say these new observations will help our understanding of the interaction between Jupiter’s winds and cloud chemistry. “The reason Jupiter seemed to ‘lose’ this band – camouflaging itself among the surrounding white bands – is that the usual downwelling winds that are dry and keep the region clear of clouds died down,” said Glenn Orton, a research scientist at JPL. “One of the things we were looking for in the infrared was evidence that the darker material emerging to the west of the bright spot was actually the start of clearing in the cloud deck, and that is precisely what we saw.”
The white band wasn’t the only change on the big, gaseous planet. At the same time, Jupiter’s Great Red Spot became a darker red color. Orton said the color of the spot – a giant storm on Jupiter that is three times the size of Earth and a century or more old – will likely brighten a bit again as the South E q ua t or ia l B e l t m a ke s i t s comeback.
This white cloud deck is made up of white ammonia ice. When the white clouds float at a higher altitude, they obscure the missing brown material, which floats at a lower altitude. Every few decades or so, the South Equatorial Belt turns completely white for perhaps one to three years, an event that has puzzled scientists for decades. This extreme change in appearance has
The South Equatorial Be lt underwent a slight brightening, known as a “fade,” just as NASA’s New Horizons spacecraft was flying by on its way to Pluto in 2007. Then there was a rapid “revival” of its usual dark color three to four months later. The last full fade and revival was a double-header event, starting with a fade in 1989, revival in 1990, then another fade and
only been seen with the South Equatorial Belt, making it unique to Jupiter and the entire solar system.
Above: This image of Jupiter is a composite of three colour images taken on Nov. 16, 2010, by NASA's Infrared Telescope Facility. The particles lofted by the initial outbreak are easily identified in green as high altitude particles at the upper right, with a second outbreak to the lower left.
www.midlandsastronomy.com Page - 6
Observations by NASA's Cassini spacecraft revealed the moons Atlas and Pan, each roughly 12 miles (20 kilometers) from pole to pole, have massive ridges bulging from their equators some 3.7 to 6.5 miles (6 to 10.5 kilometers) high, giving them the classic Earthly UFO appearance.
Above: This image is a composite of three color images taken on Nov. 18, 2010, by the Gemini North telescope in Hawaii. The composite image shows a belt that had previously vanished in Jupiter's atmosphere is now reappearing. Image credit: NASA/JPL/UH/NIRI/Gemin revival in 1993. Similar fades and revivals have been captured visually and photographically back to the early 20th century, and they are likely to be a long-term phenomenon in Jupiter’s atmosphere. Scientists are particularly interested in observing this latest event because it’s the first time they’ve been able to use modern instruments to determine the details of the chemical and dynam ica l cha ng es of this phenomenon. Observing this event carefully may help to refine the scientific questions to be posed by NASA’s Juno spacecraft, due to arrive at Jupiter in 2016, and a larger, proposed mission to orbit Jupiter and explore its satellite Europa after 2020. Observations by amateur astronomers Christopher Go of Cebu City, Philippines and Anthony Wesley of Australia have helped, and scientists have used the “big guns” in Hawaii — NASA’s Infrared Telescope Facility, the W.M. Keck Observatory and the Gemini Observatory telescope. Go imaged an outburst that piqued the interest of other astronomers.
“I was fortunate to catch the outburst,” said Christopher Go, referring to the first signs that the band was coming back. “I had a meeting that evening and it went late. I caught the outburst just in time as it was rising. Had I imaged earlier, I would not have caught it,” he said.
www.universetoday.com
To help find your way around the night sky, Skymaps.com makes available for free each month. The Evening Sky Map is suitable for all stargazers including newcomers to astronomy and will help you to: • identify planets, stars and major constellations. • find sparkling star clusters, wispy nebulae & distant galaxies. • locate and follow bright comets across the sky. • learn about the night sky and astronomy.
At first glance, one could assume that fast rates of spin might have stretched Atlas and Pan out into such unusual shapes, just as tossing a disk of pizza dough flattens it out. But astronomers discovered that each takes about 14 hours to complete a rotation not nearly fast enough to cause the flattened, disk-like shape.
Carolyn Porco, a planetary scientist at the Space Science Institute in Boulder, Colo., and her colleagues suspected these peculiar moons could be formed mostly from Saturn's rings, rather than just from fragments produced in collisions of larger moons. The location of the ridges lined up precisely with the rings of icy particles in which they were embedded, findings which are detailed in the Dec. 6 issue of the journal Science.
the rings. Computer simulations suggest one-half to two-thirds of these bizarre moons are made of ring material, piled up on massive, dense fragments of bigger moons that disintegrated billions of years ago after catastrophic collisions with one another.
After analyzing the shapes and densities of the moons from data captured by Cassini, Porco's team now finds Pan and Atlas appear to be mostly light, porous, icy bodies, just like the particles making up
Astrophysicist Sebastien Charnoz at University of Paris Diderot, the lead author of a related study suggests that the Saturnian ice-clump moons elongated and bulged out into the flying-saucer shapes in the manner
Dissolving star systems create mess in Orion For young stars, stellar outflows are the rule. T Tauri stars and other young stars eject matter in generally collimated jets. However, a region in Orion‘s giant molecular cloud known as the Becklin-Neugebauer/Kleinmann-Low (BN/KL) region, appears to have a clumpy, scattered set of outflows with “finger-like” projections in numerous directions. A new study explores this odd region. To conduct their study, the team used the Sub-millimetre Array to trace the motion of carbon monoxide gas in the area. Flying away from this region are three massive and young stars. Tracing their paths back, astronomers had previously determined that these stars likely had a common origin as members of a multiple system that for some reason, broke apart an estimated 500 years ago. Likely related to this, the new study discovered several new fingers of gas moving away as well with velocities that implied they came from the same point of origin near
the same time. But what could send stars and gas hurtling outwards? Nearby, the team also discovered a “hot core” of material as well as a “bubble” of empty space near the point of origin of the event. To explain the combination of these three events, the team proposes that an close interaction between the three stars (or perhaps more) occurred. At that time, the interaction tore apart any potential binary system throwing the stars outwards.
Above: Pan is the innermost moon of Saturn. It is a walnut-shaped small moon about 35 kilometres across and 23 km high that orbits within the Encke Gap in Saturn's A Ring. Pan acts as a ring shepherd and is responsible for keeping the Encke Gap free of ring particles.
Since the stars are young and still embedded in a nebula, the team suggests it was likely they also contained circumstellar disks that had not yet formed planets. During the interaction, the outer portions which would be least strongly bound, were thrown outwards, creating the finger-like projections. Material that was bound more tightly but just enough to be torn off, “would find itself with an excess of kinetic energy, and will start to expand” creating the apparent bubble. If that bubble, expanding supersonically for the local medium, encountered a region that was overly dense, it would collide, heating the region and potentially forming the hot core.
of accretion disks, which "are found everywhere in the universe— around black holes, around stars, around Jupiter." Charnoz added that understanding how the icy particles piled up to make these shapes could shed light on how matter in the protoplanetary disks of our Solar System that formed around our newborn sun could have clumped together to make planets.
www.dailygalaxy.com constraints on how planetary systems form since most stars form in open clusters and associations in which such interactions may be commonplace. Yet, the very fact that such destroyed systems have never been found until now imply that interactions sufficiently close to cause such disruption are rare. Regardless, such things will help astronomers form a better picture of the formation of planets.
www.dailygalaxy.com
This new discovery presents a potential first for the discovery of one or more d e s t r o y e d circumstellar disks. Such findings could help impose new
www.midlandsastronomy.com Page - 7
Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
How Jupiter is getting its belt back
Saturn's weird moon, Pan Strange flying-saucer-shaped moons embedded in Saturn's rings have baffled scientists studying images transmitted by the ESA's Cassini Spacecraft. New research suggests that the oddly shaped moons, Pan and Atlas, are born largely from clumps of icy particles in the rings themselves, a discovery that could shed light on how Earth and other planets formed from the disk of matter that once surrounded our newborn sun.
Earlier this year, one of Jupiter’s stripes went missing. The Southern Equatorial Band started to get lighter and paler, and eventually disappeared. Now, follow-up images from both professional and amateur astronomers are showing some activity in the area of the SEB, and scientists now believe the vanished dark stripe is making a comeback. They say these new observations will help our understanding of the interaction between Jupiter’s winds and cloud chemistry. “The reason Jupiter seemed to ‘lose’ this band – camouflaging itself among the surrounding white bands – is that the usual downwelling winds that are dry and keep the region clear of clouds died down,” said Glenn Orton, a research scientist at JPL. “One of the things we were looking for in the infrared was evidence that the darker material emerging to the west of the bright spot was actually the start of clearing in the cloud deck, and that is precisely what we saw.”
The white band wasn’t the only change on the big, gaseous planet. At the same time, Jupiter’s Great Red Spot became a darker red color. Orton said the color of the spot – a giant storm on Jupiter that is three times the size of Earth and a century or more old – will likely brighten a bit again as the South E q ua t or ia l B e l t m a ke s i t s comeback.
This white cloud deck is made up of white ammonia ice. When the white clouds float at a higher altitude, they obscure the missing brown material, which floats at a lower altitude. Every few decades or so, the South Equatorial Belt turns completely white for perhaps one to three years, an event that has puzzled scientists for decades. This extreme change in appearance has
The South Equatorial Be lt underwent a slight brightening, known as a “fade,” just as NASA’s New Horizons spacecraft was flying by on its way to Pluto in 2007. Then there was a rapid “revival” of its usual dark color three to four months later. The last full fade and revival was a double-header event, starting with a fade in 1989, revival in 1990, then another fade and
only been seen with the South Equatorial Belt, making it unique to Jupiter and the entire solar system.
Above: This image of Jupiter is a composite of three colour images taken on Nov. 16, 2010, by NASA's Infrared Telescope Facility. The particles lofted by the initial outbreak are easily identified in green as high altitude particles at the upper right, with a second outbreak to the lower left.
www.midlandsastronomy.com Page - 6
Observations by NASA's Cassini spacecraft revealed the moons Atlas and Pan, each roughly 12 miles (20 kilometers) from pole to pole, have massive ridges bulging from their equators some 3.7 to 6.5 miles (6 to 10.5 kilometers) high, giving them the classic Earthly UFO appearance.
Above: This image is a composite of three color images taken on Nov. 18, 2010, by the Gemini North telescope in Hawaii. The composite image shows a belt that had previously vanished in Jupiter's atmosphere is now reappearing. Image credit: NASA/JPL/UH/NIRI/Gemin revival in 1993. Similar fades and revivals have been captured visually and photographically back to the early 20th century, and they are likely to be a long-term phenomenon in Jupiter’s atmosphere. Scientists are particularly interested in observing this latest event because it’s the first time they’ve been able to use modern instruments to determine the details of the chemical and dynam ica l cha ng es of this phenomenon. Observing this event carefully may help to refine the scientific questions to be posed by NASA’s Juno spacecraft, due to arrive at Jupiter in 2016, and a larger, proposed mission to orbit Jupiter and explore its satellite Europa after 2020. Observations by amateur astronomers Christopher Go of Cebu City, Philippines and Anthony Wesley of Australia have helped, and scientists have used the “big guns” in Hawaii — NASA’s Infrared Telescope Facility, the W.M. Keck Observatory and the Gemini Observatory telescope. Go imaged an outburst that piqued the interest of other astronomers.
“I was fortunate to catch the outburst,” said Christopher Go, referring to the first signs that the band was coming back. “I had a meeting that evening and it went late. I caught the outburst just in time as it was rising. Had I imaged earlier, I would not have caught it,” he said.
www.universetoday.com
To help find your way around the night sky, Skymaps.com makes available for free each month. The Evening Sky Map is suitable for all stargazers including newcomers to astronomy and will help you to: • identify planets, stars and major constellations. • find sparkling star clusters, wispy nebulae & distant galaxies. • locate and follow bright comets across the sky. • learn about the night sky and astronomy.
At first glance, one could assume that fast rates of spin might have stretched Atlas and Pan out into such unusual shapes, just as tossing a disk of pizza dough flattens it out. But astronomers discovered that each takes about 14 hours to complete a rotation not nearly fast enough to cause the flattened, disk-like shape.
Carolyn Porco, a planetary scientist at the Space Science Institute in Boulder, Colo., and her colleagues suspected these peculiar moons could be formed mostly from Saturn's rings, rather than just from fragments produced in collisions of larger moons. The location of the ridges lined up precisely with the rings of icy particles in which they were embedded, findings which are detailed in the Dec. 6 issue of the journal Science.
the rings. Computer simulations suggest one-half to two-thirds of these bizarre moons are made of ring material, piled up on massive, dense fragments of bigger moons that disintegrated billions of years ago after catastrophic collisions with one another.
After analyzing the shapes and densities of the moons from data captured by Cassini, Porco's team now finds Pan and Atlas appear to be mostly light, porous, icy bodies, just like the particles making up
Astrophysicist Sebastien Charnoz at University of Paris Diderot, the lead author of a related study suggests that the Saturnian ice-clump moons elongated and bulged out into the flying-saucer shapes in the manner
Dissolving star systems create mess in Orion For young stars, stellar outflows are the rule. T Tauri stars and other young stars eject matter in generally collimated jets. However, a region in Orion‘s giant molecular cloud known as the Becklin-Neugebauer/Kleinmann-Low (BN/KL) region, appears to have a clumpy, scattered set of outflows with “finger-like” projections in numerous directions. A new study explores this odd region. To conduct their study, the team used the Sub-millimetre Array to trace the motion of carbon monoxide gas in the area. Flying away from this region are three massive and young stars. Tracing their paths back, astronomers had previously determined that these stars likely had a common origin as members of a multiple system that for some reason, broke apart an estimated 500 years ago. Likely related to this, the new study discovered several new fingers of gas moving away as well with velocities that implied they came from the same point of origin near
the same time. But what could send stars and gas hurtling outwards? Nearby, the team also discovered a “hot core” of material as well as a “bubble” of empty space near the point of origin of the event. To explain the combination of these three events, the team proposes that an close interaction between the three stars (or perhaps more) occurred. At that time, the interaction tore apart any potential binary system throwing the stars outwards.
Above: Pan is the innermost moon of Saturn. It is a walnut-shaped small moon about 35 kilometres across and 23 km high that orbits within the Encke Gap in Saturn's A Ring. Pan acts as a ring shepherd and is responsible for keeping the Encke Gap free of ring particles.
Since the stars are young and still embedded in a nebula, the team suggests it was likely they also contained circumstellar disks that had not yet formed planets. During the interaction, the outer portions which would be least strongly bound, were thrown outwards, creating the finger-like projections. Material that was bound more tightly but just enough to be torn off, “would find itself with an excess of kinetic energy, and will start to expand” creating the apparent bubble. If that bubble, expanding supersonically for the local medium, encountered a region that was overly dense, it would collide, heating the region and potentially forming the hot core.
of accretion disks, which "are found everywhere in the universe— around black holes, around stars, around Jupiter." Charnoz added that understanding how the icy particles piled up to make these shapes could shed light on how matter in the protoplanetary disks of our Solar System that formed around our newborn sun could have clumped together to make planets.
www.dailygalaxy.com constraints on how planetary systems form since most stars form in open clusters and associations in which such interactions may be commonplace. Yet, the very fact that such destroyed systems have never been found until now imply that interactions sufficiently close to cause such disruption are rare. Regardless, such things will help astronomers form a better picture of the formation of planets.
www.dailygalaxy.com
This new discovery presents a potential first for the discovery of one or more d e s t r o y e d circumstellar disks. Such findings could help impose new
www.midlandsastronomy.com Page - 7
Midlands Astronomy Club Magazine
Aside from categorizing galaxies, another component of the Galaxy Zoo project has been asking participants to identify potential supernovae (SNe). The first results are out and have identified “nearly 14,000 supernova candidates from [Palomar Transient Factory, (PTF)] were classified by more than 2,500 individuals within a few hours of data collection.” Although the Galaxy Zoo project is the first to employ citizens as supernova spotters, the background programs have long been in place but were generating vast amounts of data to be processed. “The Supernova Legacy Survey used the MegaCam instrument on the 3.6m Canada-France-Hawaii Telescope to survey 4 deg2” every few days, in which “each square degree would typically generate ~200 candidates for each night of observation.” Additionallly, “the Sloan Digital Sky Survey-II Supernova Survey used the SDSS 2.5m telescope to survey a larger area of 300 deg2” and “human scanners viewed 30005000 objects each night spread over six scanners”. To ease this burden, the highly successful Galaxy Zoo implemented a Supernova Search in which users would be directed through a decision tree to help them determine what computer algorithms were proposing as transient events. Each image would be viewed and decided on by several participants increasing the likelihood of a correct appraisal. Also, “with a large number of people scanning candidates, more candidates can be examined in a shorter amount of time – and with the global Zooniverse (the parent project of Galaxy Zoo) user base this can be done around the clock, regardless of the local time zone the science team happens to be based in” allowing for “interesting candidates to be followed up on the same night as that of the SNe discovery, of particular interest to quickly evolving SNe or transient sources.” To identify candidates for viewing, images are taken using the 48 inch Samuel Oschin telescope at the Palomar Observatory. Images are the n c a lib r a te d to c or r ec t instrumental noise and compared
www.midlandsastronomy.com Page - 8
automatically to reference images. Those in which an object appears with a change greater than five standard deviations from the general noise are flagged for inspection. While it may seem that this high threshold would eliminate other events, the Supernova Legacy Survey, starting with 200 candidates per night, would only end up identifying ~20 strong candidates. As such, nearly 90% of t h e s e c om p ut e r g e n e r a te d identifications were spurious, likely generated by cosmic rays striking the detector, objects within our own solar system, or other such nuisances and demonstrating the need for human analysis. Still, the PTF identifies between 300 and 500 candidates each night of operation. When exported to the Galaxy Zoo interface, users are presented with three images: The first is the old, reference image. The second is the recent image, and the third is the difference between the two, with brightness values subtracted pixel for pixel.
Sta r s w hic h d i d n’ t c ha n g e brightness would be subtracted to nothing, but those with a large change (such as a supernova), would register as a still noticeable star. Of course, this method is not flawless, which also contributes to the false positives from the computer system that the decision tree helps weed out. The first question (Is there a candidate cantered in the crosshairs of the right-hand [subtracted] image?) eliminates misprocessing by the algorithm due to misalignment. The second question (Has the candidate itself subtracted correctly?) serves to drop stars that were so bright, they saturated the CCD, causing odd errors often resulting in a “bullseye” pattern. Third (Is the candidate star-like and approximately circular?), users eliminate cosmic ray strikes which generally only fill one or two pixels or leave long trails (depending on the angle at which they strike the CCD). Lastly, users are asked if “the candidate centred in a circular host galaxy?” This sets aside identifications of variable stars within our own galaxy that are not events in other galaxies as well as supernovae that appear in the outskirts of their host galaxies.
Midlands Astronomy Club Magazine Each of these questions is assigned a number of positive or negative “points” to give an overall score for the identification. The higher the score, the more likely it is to be a true supernova. With the way the structure is set up, “candidates can only end up with a score of -1, 1 or 3 from each classification, with the most promising SN candidates scored 3.” If enough users rank an event with the appropriate score, the event is added to a daily subscription sent out to interested parties. To confirm the reliability of identifica tions, the top 20 candidates were followed up spectroscopically with the 4.2m William Herschel Telescope. Of them, 15 were confirmed as SNe, with 1 cataclysmic variable, and 4 remain unknown. When compared to followup observations from the PTF team, the Galaxy Zoo correctly identified 93% of supernova that were confirmed spectroscopically from them. Thus, the identification is strong and this large volume of known events will certainly help astronomers learn more about these events in the future. If you’d like to join, head over to their website and register. Presently, all supernovae candidates have been processed, but the next observing run is coming up soon!
www.universetoday.com
The Sun steals Comets from other Stars The next time you thrill at the sight of a comet blazing across the night sky, consider this: it's a stolen pleasure. You're enjoying the spectacle at the expense of a distant star. Sophisticated computer simulations run by researchers at the Southwest Research Institute (SWRI) have exposed the crime. "If the results are right, our Sun snatched comets from neighbouring stars' back yards," says SWRI scientist Hal Levison. And he believes this kind of thievery accounts for most of the comets in the Oort Cloud at the edge of our solar system. "We know that stars form in clusters. The Sun was born within a huge community of other stars that formed in the same gas cloud. In that birth cluster, the stars were close enough together to pull comets away from each other via gravity. It's like neighbourhood children playing in each others' back yards. It's hard to imagine it not happening." According to this "thief" model, comets accompanied the nearest star when the birth cluster blew apart. The Sun made off with quite a treasure – the Oort Cloud, which was swarming with comets fr om a ll over the "neighbourhood." The Oort cloud is an immense cloud of comets orbiting the Sun far beyond Pluto. It is named after mid -20th century Dutch astronomer Jan Oort, who first proposed such a cloud to explain the origin of comets sometimes seen falling into the inner solar system. Although no confirmed direct observations of the Oort cloud have been made, most astronomers believe that it is the source of all long-period and Halley -type comets. The standard model of comet production asserts that our Sun came by these comets honestly. "That model says the comets are dregs of our own solar system's planetary formation and that our planets gravitationally booted them
to huge distances, populating the cloud. But we believe this kind of scenario happened in all the solar systems before the birth cluster dispersed." Otherwise, says Levison, the numbers just don't add up. "The standard model can't produce anywhere near the number of comets we see falling in from the Oort Cloud. The Sun's sibling stars had to have contributed some comets." Comets in the Oort Cloud are typically 1 or 2 miles across, and they're so far away that estimating their numbers is no easy task. But Levison and his team say that, based on observations, that there should be something like 400
Above: Compared to the size of planetary orbits, the Oort cloud is very far away. Indeed, the estimated size of the Oort cloud is approximately 1 light year. If the Sun passed within 2 light years of another sun-like star, the stars' Oort clouds would overlap and their comets would intermingle. Image credit: ESO. billion comets there. The "domestic" model of comet formation can account for a population of only about 6 billion. "That's a pretty anemic Oort Cloud, and a huge discrepancy – too huge to be explained by mistakes in the estimates. There's no way we could be that far off, so there has to be something wrong with the model itself." He points to the cometary orbits as evidence. "These comets are in very odd orbits – highly eccentric long-period orbits that
take them far from our Sun, into remote regions of space. So they couldn't have been born in orbit around the Sun. They had to have formed close to other stars and then been hijacked here." This means comets can tell us not only about the early history of the Sun – but also about the history of other stars.
www.science.nasa.gov
Alien worlds observed in Galaxies beyond Milky Way With some 500 known exoplanet apparently all around us (galactically speaking), a global team of researchers have kicked it up a notch. Signals shining across millions of light years, from other galaxies, indicate the birth of solar systems - and we can see them. The work is based on spectroscopy, the science of examining what wavelengths of light come in and extracting all kinds of information from it (far more than our eyes, which just say "that's blue" and call it a day). Every material has a unique emission spectrum (very specific wavelengths they emit) and any intervening material absorbs it
(according to the same spectroscopic signature). This technique allows us to 'see' even when the light source is too faint or far away to make out detail any other way. The Spitzer Space Telescope and I nfr ar ed Spa c e Obs e r va tor y collected data from over eighty galaxies, and from these mindmeltingly far-flung light sources we can see spectroscopic signs of spawning solar systems. The received light (once adjusted for intergalactic red shift) shows three peaks: a huge spike for stellar material, a second peak from heated interstellar dust, and a faint third bump thought to result from circumstellar discs of material like the one that eventually formed us.
This is awesome science: as well as literally finding new worlds where no-one has gone before, we can use this new discovery as a (limited) window into the history of our own system. Discovering new things, and then using those to learn more new things.
www.dailygalaxy.com
www.midlandsastronomy.com Page - 5
Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Tenuous Oxygen atmosphere found around Saturn’s moon Rhea A few years ago, astronomers thought they found wispy rings around Saturn’s moon Rhea. Although the possibility of rings around this icy moon was later nixed, astronomers knew there was still something around Rhea that was causing a strange, symmetrical structure in the charged-particle environment around Saturn’s second-largest moon. Now, new observations have shown something else around Rhea that was completely unexpected: an oxygen atmosphere. In March of this year, the Cassini spacecraft made a close flyby of Rhea and recorded data showing a thin atmosphere made up of oxygen and carbon dioxide. The source of the oxygen is not really a surprise: Rhea’s density of 1.233 times that of liquid water suggests that Rhea is three quarters ice and one quarter rock. The moon’s tenuous atmosphere is maintained by the on going chemical decomposition of ice water on the moon’s surface by irradiation from Saturn’s magnetosphere. Oxygen has also recently been detected in the atmospheres of two of Jupiter’s moons, Europa and Ganymede. Since oxygen is a main
component of the atmosphere surrounding Satur n’s ring s, astronomers think there could be similar atmospheres around other icy moons that orbit inside Saturn’s magnetosphere. “The new results suggest that active, complex chemistry involving oxygen may be quite common throughout the solar system and even our universe,” said lead author Ben Teolis, a Cassini team scientist. “Such chemistry could be a prerequisite for life. All evidence from Cassini indicates that Rhea is too cold and devoid of the liquid water necessary for life as we know it.”
Fermi telescope finds giant structure in the Milky Way
Of course, there’s always the possibility of life as we don’t know it. And, there must be s om e s or t of organics on the moon – meaning carbon compounds. The source of the carbon dioxide in Rhea’s atmosphere is not yet known, but its presence Above: Rhea, as seen by Cassini. Credit: NASA suggests that radiolysis reactions between oxidants and organics dioxide of around 20 billion are on going at the moon’s molecules per cubic meter. surface. The plasma spectrometer saw clear This latest data came from Cassini’s signatures of flowing streams of ion and neutral mass spectrometer positive and negative ions, with a n d t h e C a s s i n i p l a s m a masses that corresponded to ions spectrometer during flybys on Nov. of oxygen and carbon dioxide. The 26, 2005, Aug. 30, 2007, and oxygen appears to rise to an March 2, 2010. The ion and neutral a t m o s p h e r e w h e n S a t u r n’ s mass spectrometer saw peak magnetic field rotates over Rhea. densities of oxygen of around 50 Energetic particles trapped in the billion molecules per cubic meter. It planet‘s magnetic field pepper the detected peak densities of carbon moon’s water-ice surface. They cause chemical reactions that decompose the surface and release oxygen. Releasing oxygen through surface irradiation could help generate conditions favourable for life at an icy body other than Rhea that has liquid water under the surface. If the oxygen and carbon dioxide from the surface could somehow get transported down to a subsurface ocean, that would provide a much more hospitable environment for more complex compounds and life to form. The scientists are unsure how the carbon dioxide is released. It could be the result of “dry ice” trapped from the primordial solar nebula, as is the case with comets, or it may be due to similar irradiation processes operating on the organic molecules trapped in the water ice of Rhea. The carbon dioxide could also come from carbon-rich materials deposited by tiny meteors that bombarded Rhea’s surface.
Above: The 2 March 2010 Rhea flyby trajectory and simulated oxygen atmosphere distribution. Inset: Predicted oxygen density (yellow) compared to the INMS measurement (white) during the flyby.
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NASA’s Fermi Gamma-ray Space Telescope has unveiled a previously unseen structure centred in the Milky Way. The feature spans 50,000 light-years and may be the remnant of an eruption from a supersized black hole at the centre of our galaxy. “What we see are two gamma-rayemitting bubbles that extend 25,000 light-years north and south of the galactic centre,” said Doug Finkbeiner, an astronomer at the Harvard-Smithsonian Centre for Astrophysics, who first recognised the feature. “We don’t fully understand their nature or origin.” The structure spans more than half of the visible sky, from the c ons te lla tio n V ir g o to t he constellation Grus, and it may be millions of years old. A paper about the findings has been accepted for publication in The Astrophysical Journal. Scientists now are conducting more analyses to better understand how the never-before-seen structure was formed. The bubble emissions are much more energetic than the gamma-ray fog seen elsewhere in the Milky Way. The bubbles also appear to have well-defined edges. The s truc tur e’s s hape a nd
emissions suggest it was formed as a result of a large and relatively rapid energy release — the source of which remains a mystery. One possibility includes a particle jet from the supermassive black hole at the galactic centre. In many other galaxies, astronomers see fast particle jets powered by matter falling toward a central black hole. While there is no evidence the Milky Way’s black hole has such a jet today, it may have in the past. The bubbles also may have formed as a result of gas outflows from a burst of star formation, perhaps the one that produced many massive star clusters in the Milky Way’s centre several million years ago. “In other galaxies, we see that starbursts can drive enormous gas outflows,” said David Spergel, a scientist at Princeton University. “Whatever the energy source behind these huge bubbles may
Upcoming flybys could provide clues to interior of Enceladus What is going on inside Saturn’s moon Enceladus and what powers the icy geysers and jets? A pair of upcoming flybys by the Cassini spacecraft could help answer those questions. Radio instruments on board will measure the gravity field of Enceladus and focus particularly on the very intriguing south polar hot spot.
Above: At least four distinct plumes of water ice spew out from the south polar region of Saturn's moon Enceladus. Credit: NASA/JPL/Space Science Institute
Of course, the success of these flybys hinges on the Cassini mission controllers being able to wake up the dormant spacecraft which has been in safe mode since November 2. Teams will attempt to
Above: From end to end, the newly discovered gamma-ray bubbles extend 50,000 light-years, or roughly half of the Milky Way's diameter, as shown in this illustration. Credit: NASA be, it is connected to many deep questions in astrophysics.”
in France, Germany, Italy, Japan, Sweden and the United States.
“Fermi scans the entire sky every three hours, and as the mission continues and our exposure deepens, we see the extreme universe in progressively greater detail,” said Julie McEnery, Fermi project scientist at NASA’s Goddard Space Flight Centre. NASA’s Fermi is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners
“Since its launch in June 2008, Fermi repeatedly has proven itself to be a frontier facility, giving us new insights ranging from the nature of space-time to the first observations of a gamma-ray nova,” said Jon Morse, Astrophysics Division director at NASA. “These latest discoveries continue to demonstrate Fermi’s outstanding performance.”
get Cassini up and running again tomorrow, November 24, and they don’t anticipate any problems.
There will be two three-hour “wing” observations before and after closest-approach (from five to eight hours from closest approach on either side), and then three more hours cantered directly around closest approach. The Cassini team is throwing almost the entire gamut of instruments into the flyby program, between radio science (RSS) observations, the imaging science system (ISS) and composite infrared spectrometer (CIRS) which will observe this moon on the inbound leg, and CIRS and the visible and infrared mapping spectrometer (VIMS) which will take data on the outbound leg, with other optical remote sensing and fields, particles and waves instruments also taking data.
Cassini went into the protective standby mode and the likely cause of the problem was a faulty program code line, or a flipped bit in the spacecraft’s command and data system computer. The upcoming flybys of Enceladus will put Cassini very close – about 48 kilometres (30 miles) above the surface. The first will take place on November 30. Pairing this flyby with one on April 28, should provide scientists enough information to determine the nature of the interior right under the hot spot. The next flyby on December 21, Cassini will make 50-kilometer pass over the north pole of Enceladus. The fields and particles instruments will be trying to “sniff” anything coming from the moon.
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Midlands Astronomy Club Magazine
Kid’s Korner Do constellations ever break apart ever or change? Our friends at the Cable Natural History Museum in Cable, Wisconsin, ask whether constellations ever break apart or change. To answer this, first let's think about what the constellations are, and then we can see whether they change. When we look at the night sky, we see distant stars shining like faint lights. Now we know they are really brilliant lights, like the Sun, that are incredibly far away from us and from each other. Astronomers have used some wonderfully inventive methods to discover the distances to the stars, but to our eyes, they all look as if they are pinpoints of light at the same distance. As an extreme example of this, the red planet Mars is tens of millions of times closer than the red star Antares (Greek for "Rival of Mars"), but you certainly can't tell that just by looking at them when they appear near each other in our skies.
of the nature of stars and space, saw these patterns and thought they might be important symbols. Cultures throughout history have created different names and descriptions for the arrangements of stars. The constellations most of us are familiar with were created by people living in the Mediterranean and the Middle East. Many of the stories of the constellations tell us about the myths and legends of the people who gave them names thousands of years ago, but they tell us nothing about the stars themselves.
If stars never changed, then constellations wouldn't change. But the stars, including the Sun, travel in their own separate orbits through the Milky Way galaxy. The stars move along with fantastic speeds, but they are so far away that it takes a It's normal for us to find patterns in long time for natural arrangements of things. For their motion to example, most people can imagine they see faces or other familiar objects in some clouds or rock formations. It's the same with the stars. Ancient observers, without the benefit of our m o d e r n understanding
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be visible to us. You can understand this by moving your finger in front of your eyes. Even when you move it very slowly, it may appear to move faster than a speeding jet that is many miles away. Even the fastest stars take a long time to travel a noticeable distance. A faint star named Barnard's Star moves the fastest through our skies. Still, for it to change its position only by an amount equal to the width of the moon would take about 180 years. The constellations surely change shape, but seeing the changes would require superhuman patience!
Midlands Astronomy Club Magazine was enough for Halley to realize that those stars must have moved. If you waited long enough, the patterns of stars you would see in the sky would change completely. The Big Dipper is the easily recognizable part of a constellation called Ursa Major, or the Great Bear. The star at the end of the handle and the one at the far tip of the bowl happen to be moving in the opposite direction from the other stars in the Big Dipper. In the future, the handle will appear to be more bent, and the bowl will spread out. To me, the shape in 5 0 , 00 0
years will be more like that of a tadpole than a dipper. Be s id e s th e i r m o t io n, t he appearances of stars change as they age. Take my favourite constellation Scorpius, for example. A couple of years ago, the middle of the three stars that make the head of the scorpion became brighter. The constellation now has a new look! The constellations are a very convenient way to locate objects in the splendid night sky, making a kind of natural map. If you knew the names of the constellations, you could follow directions to all sorts of beautiful and interesting objects, just as if you knew the names of streets, you could follow directions on how to get to a friend's house.
The person who discovered that the stars move was the great British astronomer Edmond Halley, who also has a famous comet named after him. Almost 300 years ago he noticed that a few stars in charts made by Greek sky watchers were not in quite the same location anymore. Those charts were more than 1600 years old then, and even over that time, the bright stars Sirius, Arcturus, and Aldebaran had shifted position only slightly. Still, it
To make your own star finder and learn some of the constellations, go to The Space Place Web site at spaceplace.nasa.gov and click on "Make spacey things." Then I hope you will go outside to look at the stars, and use the constellations to find your way around. Remember, though, that what's important is not these patterns themselves, but rather the richness of the universe they will help you discover.
"Limits of organic life": NASA to search for 'weird' non-carbon-based life The recent announcement by NASA of the discovery of the possibility of arsenic-based life in Mono Lake fits hand-in-glove with NASA's strategy to expand the search for life beyond Earth to extreme non-carbon-based life. No discovery that we can make in our exploration of the solar system would have greater impact on our view of our position in the cosmos, or be more inspiring, than the discovery of an alien life form, even a primitive microbial one. The discovery over the past decade of extreme life forms thriving on Earth at the super-heated walls of Ocean volcanic vents and in the interior regions of the planet's crust, led to a seminal 2009 report, The Limits of Organic Life in Planetary Systems, by the National Research Council (NRC). The NASA sponsored report recommended that the search for beyond Earth’s solar system
should be widened throughout the universe to include the possibility of “weird” life. "Nothing," the report concludes, "would be more tragic in the American exploration of space than
Above: An image GFAJ-1 grown on arsenic. Left: Felisa Wolfe-Simon processing mud from Mono Lake to inoculate media to grow microbes on arsenic.
Above: An image of Mono Lake Research area where the discovery of arsenicbased life has been discovered. to encounter alien life and fail to recognise it.” Earth did not accumulate oxygen during the first roughly 3 billion years, or form an ozone layer until about 1.5 billion years ago. There is considerable emphasis on looking for contemporary Earth atmospheres that have oxygen and an ozone layer, but, the report hits home, we should also be using models with different anaerobic microbial non-carbon ecosystems, atmospheres that might parallel the different stages in the evolution of Earth's atmospheres over 4 billion years, and conditions that could indicate the presence of a tectonically active planet. The report pointed out that the exploration of the planet is concentrated on looking for places
where liquid water exists—which goes along with the idea of where life is found on the Earth. However, they emphasize that liquids such as ammonia, methane, and formamide could also be the building blocks for life. Saturn's moon, Titan is a perfect candidate: the discovery of evidence of liquid water-ammonia on Titan provides the potential for life-bearing polar fluids outside what is normally regarded as the habitable zone. The stay of the Cassini-Huygens mission on the surface of Titan was unfortunately brief; but Titan is the locale that is likely to support exotic life, which could be discovered using robotic remote sensing devices. http://www.dailygalaxy.com
ISS Celebrates 10 Years of Human Habitation Last month the International Space Station has had a human crew since 2000. Ten years! Ten years, 200 inhabitants, 15 nations, 600 experiments and NASA's first robot space assistant signalling the beginning of the Age of Space Droids! An international outpost one official wag dubbed the "zero gravity United Nations." A rare and refreshing a symbol of international cooperation and worldwide unity. More than 200 orbiting explorers have visited the space complex; 15 nations have contributed to the missions, providing modules and hardware; and more than 600 experiments have been carried out on board. http://www.dailygalaxy.com
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Midlands Astronomy Club Magazine
Galaxy Zoo: The hunt for supernovae ................................... 8 Fermi telescope finds giant structure in the Milky Way ........... 9
Front cover image: Spooky shapes seem to haunt this starry expanse, drifting through the night in the royal constellation Cepheus. Of course, the shapes are cosmic dust clouds faintly visible in dimly reflected starlight. Far from your own neighbourhood on planet Earth, they lurk at the edge of the Cepheus Flare molecular cloud complex some 1,200 light-years away. Over 2 light-years across the ghostly nebula known as vdB 141 or Sh2-136 is near the centre of the field. The core of the dark cloud on the right is collapsing and is likely a binary star system in the early stages of formation.
Upcoming flybys could provide clues to interior of Enceladus ....................................................................... 9
Kids Section Kids Korner ....................................................................... 10
Quizzes and Games Exercise your brain ............................................................ 11
Monthly Sky Guide Beginners sky guide for December ..................................... 12
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4. The smaller, Earth-like planets are called 'terrestrial' planets. What are the larger planets called? Saturnine Jovian Torrential Uranian 5. Which moon of Saturn is one of the only two moons in the solar system with an atmosphere? Titan Io Triton Charon
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9. The galaxy known as IRAS F10214+4724 is how many times brighter than the sun? 500 7,000 5,000 300,000,000,000,000 10.What was the name of the comet that made its closest approach to Earth on March 22, 1997? Hale-Bopp Encke's comet Halley's comet Herschel's comet
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8. What is it called when we have a second full moon within one month? Blue moon New moon Full moon To the moon Alice!
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Check your answers
Answer 1: Plasma is usually an ionized gas, meaning that one electron has been taken or added to an accumulation of atoms or molecules.
Dissolving star systems create mess in Orion ........................ 7
White layers of clouds on Jupiter The division of the large and small planets Space between the asteroids and Mars A gap in Saturn's rings
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Answer 6: The correct answer was Southern Cross. The 'crux' of this matter is that you can only see the Southern Cross in the sky if you live in the southern hemisphere...it's worth the trip (unless you already live there, then no trip is needed of course!)
Saturn's weird moon, Pan .................................................... 7
3. What in our solar system is the Cassini Division?
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Answer 2: Edwin Hubble was a great American astronomer from the early 20th century. One of his major discoveries was to ascertain with proof that there are other galaxies outside the Milky Way.
How Jupiter is getting its belt back ....................................... 6
Great and little dog Big and little dipper Orion and his dog Big and little lion
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Answer 7: The 3 stars in the bow that makes up the handle of the Big Dipper direct ones eye toward the North Star, Polaris. Polaris lies at the tip of the Little Dipper's handle. By the way, the term 'Ursa' is Latin for 'bear'...the great and small bear.
Alien worlds observed in Galaxies beyond Milky Way ............. 5
Mercutio Galileo Edwin Isaac
7. P o r t i o n s of the constellations Ursa Major and Ursa Minor are also known as what?
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Answer 8: The correct answer was Blue moon. I will leave this one to your imagination, as I hum the tune 'Blue Moon'...
The Sun steals Comets from other Stars ............................... 5
2. We have all heard of the Hubble space telescope. What was the first name of the astronomer with the last name Hubble?
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Answer 3: Gioovanni Domenico Cassini was an Italian-French astronomer from the late 17th-early 18th century. He followed up on Galileo's work with a more powerful telescope, one that allowed him to discover four moons of Saturn and the gaps in Saturn's rings that bear his name.
You can see more about the club and its events on www.midlandsastronomy.com or contact the club via e-mail at tullamoreastronomy@yahoo.co.uk. Meetings are informal and are aimed at a level to suit all ages.
Tenuous Oxygen atmosphere found around Saturn’s moon Rhea ......................................................................... 4
Northern Crown Northern Cross Southern Cross Southern Crown
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Answer 9: The correct answer was 300,000,000,000,000. Do not, I repeat, do not look at this galaxy with your naked eye. Well, actually from Earth you would have no problem...you see, it's millions of light years away from us and barely visible with the naked eye.
ISS Celebrates 10 Years of Human Habitation ....................... 3
Gas Plasma Solid Liquid
SUDOKU
6. The constellation 'Crux' is probably better known as what?
Answer 4: The 'terrestrial' planets are so named because they have hard, rocky surfaces like the Earth...terra firma. The Jovian planets are named for Jupiter, the king of the Roman gods and the largest planet. They are also called the 'gas giants'.
"Limits of Organic Life": NASA to Search for 'Weird' Non-Carbon-Based Life ........................................................ 3
1. What state of matter is our Sun mainly consisted of?
Answer 10: Not coincidentally, the Hale -Bopp comet was discovered by a pair of scientists with the last names 'Hale' and 'Bopp'!
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All are welcome to attend. It also holds infrequent Observing Nights at its Observing Site in Clonminch, or at a member’s house (weather permitting) on the first Friday of every month..
Exercise your brain
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Answer 5: Titan is though to have its own atmosphere, it is not the largest moon in the solar system. That title belongs to Jupiter's moon Ganymede! Triton, a moon of Neptune, also has a thin but viable atmosphere.
MAC meets on the first Tuesday of the month in the Presbyterian Hall, High Street, Tullamore from 8pm.
Midlands Astronomy Club Magazine
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Midlands Astronomy Club Magazine
Sky Guide - Beginner’s targets for December The good news in December is that it gets dark nice and early allowing for long observing sessions. The bad news for those of us in the North is that the price we pay for the early evenings is the cold that accompanies it. So, fill your thermos with some nice hot coffee or hot chocolate and enjoy the wonderful winter skies. We'll start off again this month naked eye. The Geminid Meteor Shower peaks on the 13th. This is usually one of the best meteor showers of the year and should offer excellent viewing this year as the moon is in good position (waning crescent). The Geminids will seem to radiate from a point near the stars Castor and Pollux. Castor and Pollux are to the upper right of the famed Betelgeuse in Orion. Watch this area of the sky from a dark site and you can expect to see as many as 60 - 80 meteors an hour. Telescope Targets December continues to offer wonderful views of Cassiopea, Andromeda, Auriga and Perseus. See October's and November's picks pages for targets in these constellations. The Pleiades (M45) or also known as the Seven Sisters is a wonderful low power open cluster in the constellation Taurus. It is among the nearest star clusters, and is
Issue 19 - December, 2010
probably the best known, and is certainly the most obvious to the naked eye. It is easily identified high in the Southeast early after sunset. Look for 6 stars that appear to be a miniature version of the big dipper. Point your telescope with it's lowest power eyepiece at this and you'll be shocked at how many stars are visible. They are located at a distance of 400 light years from us and contain 100 stars. This cluster is approximately 78 million years old. Also in the same area of sky are the Hyades. This is one of those targets best seen with binoculars. The Hyades are a huge open cluster of 350 stars located at a distance of 150 Light years from us. The Hyades are below the Pleiades. Look for the "V" shaped grouping of stars and point your binoculars or your telescope toward them. The Hyades hold the distinction of being the closest open cluster to us.
Taurus is one of the constellations of the zodiac. It sits large and prominent in the Northern Hemisphere winter sky, between Aries to the west and Gemini to the east; to the north lie Perseus and Auriga, to the southeast Orion, to the south Eridanus, and to the southwest Cetus. Behind the star Aldebaran lie the Hyades, the nearest distinct open star cluster, that with it form a V, or an A, in the sky marking the bull's head. In the west of the constellation lie the Pleiades, one of the best known open clusters, easily visible to the eye. Another object, visible in a telescope, is the Crab Nebula (M1), a supernova remnant northwest of Îś Tauri. The explosion, seen on Earth on July 4, 1054, was bright enough to be seen by day. It is mentioned in Chinese history texts.
Well, that's about it for this month. Orion is rising in the south and will offer lots of targets for late evening this month also. I will detail these in January's picks.
Clear skies and good hunting!
By Kevin Daly http://members.aol.com/kdaly10475/index.html
Planets Jupiter is in excellent position for viewing right after sunset positioned high in the southern sky. Saturn is also in great position for viewing in the Southeast in the early evening. Show some family or friends this superstar of the sky.
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Club Notes Club Observing: Remember the next club meets every first Friday of the month for our observing sessions held in the MAC grounds. If you wish to be informed of these sessions please email your name and mobile number to midlandsastronomy@gmail.com who will confirm if the session is going ahead (depending on weather).
Kids Astronomy
MAC is a proud member of The Pleiades cluster is dominated by hot blue stars that have formed within the last 100 million years. Dust that forms a faint reflection nebulosity around the brightest stars was thought at first to be left over from the formation of the cluster, but is now known to be an unrelated dust cloud in the interstellar medium that the stars are currently passing through. Astronomers estimate that the cluster will survive for about another 250 million years, after which it will disperse due to gravitational interactions with its galactic neighbourhood.
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Quizzes and Games Monthly Sky Guide