Midlands Astronomy Club Magazine
Sky Guide - Beginner’s targets for May General notes May presents some wonderful observing opportunities this year. Starting off with the naked eye, There are two showers this month. The first shower is the Eta Aquarids which peaks on the morning of the 6th. The predictions for this shower vary between 40 and 85. These are typically fast, bright meteors and are of a similar speed to the Perseids. Some will leave persistent trains. However it is not a well placed shower for us. The radiant only rises at 04:00, however on a positive note, there will be no lunar interference. The second shower this month is a minor one. They are the Eta Lyrids, peaking on the 9th with a ZHR of 3. There will be some lunar interference with first quarter moon in the night sky.
Telescope Targets Many of March's and April's targets are still available for viewing. See those month's picks for these targets. We'll add a couple of globular clusters to our hunt this month. M3 in Cane Venatici is one of the brightest globulars in the sky (along with M13 and Omega Centauri). To find M3, use the end star of the big dipper's handle (Alkaid) and the very bright star Arcturus.
Issue 43 - May, 2013
About halfway between these 2 stars and slightly to the west is a dimmer star called Beta Comae. Place Beta Comea at the edge of your finder's FOV (moving to the east), at this point, M3 should be at the opposite edge of the finderscope field. Centre M3 and enjoy the view! Don't be afraid to increase the power on this one and see how many individual stars you can pick out. The good news is that M3 should be bright enough to be seen even from moderately light polluted locations, the bad news is that Beta Comea will be invisible to hop from. I've managed to find M3 by using Alkaid and Arcturus and scanning the area halfway between them with the scope at low power (albeit somewhat challenging). M3 contains as many a 500,000 stars packed into an area of space approximately 200 Lightyears in diameter. It is located approximately 40,000 light-years from us and it's age is estimated at 10 - 15 billion years old. M53 is another globular cluster which is located in the constellation Coma Berenices. Using Arcturus and a much dimmer star just to the west (Muphrid) as our distance measure go approximately twice this distance and slightly north to M53. M53 will take somewhat darker skies to locate than M3.
M53 contains approximately 100,000 stars spanning about 300 light-years across. It is located approximately 65,000 light-years from us. Also in Coma Berenices is a fairly bright galaxy, M64 (The Blackeye Galaxy). Just north (up from) of M53 is M64 (about the same distance as the distance between Arcturus and Muphrid. Distance estimates to this Spiral Galaxy range from 10 - 40 million lightyears. The size estimates for this one range from 25,000 to 100,000 light-years in diameter. You will need dark skies to hunt this one down.
Club Notes Club Observing: The next club meets every 1st and 3rd Saturday 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).
MAC is a proud member of
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Planets Saturn is visible as an evening object during the month and rises during daylight hours throughout the month. With the planet’s ring plane starting to open up, this is not a good time to try and observe the rings in their full glory. It is however a good time to try and observe the smaller satellites and details on the planet’s surface with the rings out of the picture.
Above: The M3 cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is located at a distance of about 33,900 lightyears away from Earth. Mercury, Venus, Mars, Jupiter, Uranus and Neptune are all in the morning sky this month and are not observable this month.
General notes Check out www.heavensabove.com for the latest passes of the International Space Station and satellites, details of Space Shuttle launches and passes and for details of Iridium Flare activity. Clear skies and good hunting!
By Kevin Daly http://members.aol.com/kdaly10475/index.html
Latest Astronomy and Space News Club News Kids Astronomy Quizzes and Games Monthly Sky Guide Internet Highlights
Midlands Astronomy Club Magazine
Saturn's moons: Facts about the ringed planet's satellites ...... 6 Two fine double stars in the Northern Dippers ...................... 8
Club News Club news ........................................................................... 9
Kids Korner ....................................................................... 10
Sculpted by stellar winds and radiation, the star factory known as Messier 17 (Omega Nebula or the Swan Nebula) lies some 5,500 light-years away in the nebula-rich constellation Sagittarius and spans almost 100 light-years. The sharp, composite, colour image utilizing data from space and ground based telescopes, follows faint details of the region's gas and dust clouds against a backdrop of the Milky Way. Stellar winds and energetic light from hot, massive stars formed from M17's stock of cosmic gas and dust have slowly carved away at the remaining interstellar material producing the cavernous appearance and undulating shapes.
Credit & Copyright: Subaru Telescope (NAOJ), HST, Colour data: Wolfgang Promper, Processing: Robert Gendler
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Methane Giants Class N Reducing Planets Minshara Class Ice Giants
Dark Matter signals recorded in Minnesota mine.................... 8
Kids Section Front cover image:
2. What class of planets does Neptune and Uranus belong to?
Quizzes and Games Exercise your brain ............................................................ 11
Monthly Sky Guide Beginners sky guide for this month .................................... 12
Internet Highlights Special content only available with the online version of the magazine ................................................................ 13
3. Which of the following is NOT true of the all gas giants in our solar system? They all have many moons. They all have ring systems. They all lack a solid surface. They all generate less energy than they take in from the sun. 4. The first extrasolar planet was discovered in 1992. What type of planet was discovered at this time? a a a a
brown dwarf gas giant rocky planet Hot Neptune
5. The precise size of a gas giant can be determined by which of the following planet-finding techniques? wobble method
Their mass is close to the size of Jupiter or larger. They orbit their parent star at a distance of between .015 and 0.5 astronomical units. They most likely formed at their present location in relation to their host star. They have a greater chance of transiting their host star. 7. Some extrasolar gas giants are thought to have migrated to the edge of their solar systems by which type of resonance? Laplace resonance secular resonance Linblad resonance mean motion orbital resonance 8. One type of Jovian planet has a very unusual orbit as well as a very large mass. The presence of this type of planet may cause Earthlike planets to be moved out of the habitable zone of its host star. What are these planets called? Eccentric Jupiters Elliptical Giants Puffy Planets Radical Giants
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Check your answers
Answer 5. The correct answer was transit technique. The transit technique is one in which the observed planet transits or passes directly in front of its home star with respect to the earth. This enables scientists to determine its size.
per hour! ............................................................................ 5
3 6. Which of the following is NOT true of hot Jupiters?
Answer 1. The correct answer was hydrogen and helium. Gas Giants are often called Jovian planets, named after Jupiter, a classic example of a gas giant, although there is a lot of variety among this class of planets.
You can see more about the club and its events on www.midlandsastronomy.com or contact the club via e-mail at midlandsastronomy@gmail.com Meetings are informal and are aimed at a level to suit all ages.
Black Hole flings companion star at 2,000,000 Kilometres
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Answer 2. The correct answer was Ice Giants. Methane is the component that gives Neptune and Uranus their blue colour.
Rain is falling from Saturn’s rings ......................................... 4
hydrogen and methane oxygen and carbon dioxide hydrogen and helium nitrogen and hydrogen
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Answer 6. The correct answer was They most likely formed at their present location in relation to their host star. It is thought that Hot Jupiters migrated from a distance farther out from their host sun to their present location because there would not have been enough material in that close proximity to a star for a planet of such a large size to have formed. One astronomical unit is equal to the distance from the Earth to the sun.
Type Ia Supernova .............................................................. 4
SUDOKU
Answer 3. The correct answer was They all generate less energy than they take in from the sun. Jupiter produces more heat than it receives from the sun. This is thought to be because its "surface" is cooling, which causes compression of its layers resulting in heat production. This is called the KelvinHelmholtz mechanism. Saturn seems to do the same, but it is not certain as to whether the heat production is as great or not. All four of the gas giants in our solar system have rings as well as many moons, from as few as eight to almost twenty.
Hubble telescope breaks record in finding most distant
gravitational microlensing radial velocity technique transit technique
Answer 7. The correct answer was mean motion orbital resonance. The gravitational pull of the orbits of the two planets gradually move them further out. Some believe that it is possible that the mean motion orbital resonance between Jupiter and Saturn caused a gravitational push that sent Uranus and Neptune into higher orbits. This gives new meaning to the term "Dancing With the Stars".
Mysterious hot spots observed in Betelgeuse ........................ 3
1. Two gases make up the main components of Jupiter and Saturn. What are they?
Answer 8. The correct answer was Eccentric Jupiters. Eccentric Jupiters often have an elliptical orbit, like comets. One source sited reported that approximately 7% of the exoplanets are of this type. As research continues that percentage will possibly change.
Latest Astronomy and Space News
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 Saturday of every month..
Exercise your brain
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Answer 4. The correct answer was a rocky planet. Actually it was a pair of rocky planets that was discovered in 1992 by two radio astronomers (Aleksander Wolszczan and Dale Frail) and this discovery was quickly confirmed. They were orbiting a star in the constellation Virgo, located 980 light-years from the Earth. The first gas giant was discovered by Michel Mayor and Didier Queloz of the University of Geneva in 1995; it was named 51 Pegasi B-Bellerphon.
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 Why is the Sky Blue?
Like energy passing through the ocean, light energy travels in waves, too. Some light travels in short, "choppy" waves. Other light travels in long, lazy waves. Blue It is easy to see that the sky is blue. light waves are shorter than red Have you ever wondered why? A lot light waves. of other smart people have, and it took a long time to figure it out! All light travels in a straight line unless something gets in the way The light from the Sun looks white. to: But it is really made up of all the colours of the rainbow. • reflect it (like a mirror)
• bend it (like a prism) A prism is a specially shaped crystal. When white light shines • or scatter it (like molecules of the gases in the atmosphere) through a prism, the light is separated into all its colours. The light you see is just one tiny bit of all the kinds of light energy S u n l i g h t r e a c h e s E a r t h ' s beaming around the Universe--and atmosphere and is scattered in all directions by all the gases around you! and particles in the air. Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colours because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.
Closer to the horizon, the sky fades to a lighter blue or white. The sunlight reaching us from low in the sky has passed through even more air than the sunlight reaching us from overhead. As the sunlight has passed through all this air, the air molecules have scattered and rescattered the blue light many times in many directions. Also, the surface of Earth has reflected and scattered the light. All this scattering mixes the colours together again so we see more white and less blue.
Midlands Astronomy Club Magazine What Makes a Red Sunset? As the Sun gets lower in the sky, its light is passing through more of the atmosphere to reach you. Even more of the blue light is scattered, allowing the reds and yellows to pass straight through to your eyes. Sometimes the whole western sky seems to glow. The sky appears red because larger particles of dust, pollution, and water vapour in the atmosphere reflect and scatter more of the reds and yellows. Why Does Light Scattering Matter? How much of the Sun's light gets bounced around in Earth's atmosphere and how much gets reflected back into space? How much light gets soaked up by land and water, asphalt freeways and sunburned surfers? How much light do water and clouds reflect back into space? And why do we care? Sunlight carries the energy that heats Earth and powers all life on Earth. Our climate is affected by how sunlight is scattered by forests, deserts, snow- and ice-covered surfaces, different types of clouds, smoke from forest fires, and other pollutants in the air.
Mysterious hot spots observed in Betelgeuse A new image of Betelgeuse, a nearby red supergiant, shows it has both hot spots and a giant arc of cool gas extending far beyond its atmosphere. Astronomers have released a new image of the outer atmosphere of Betelgeuse — one of the nearest red supergiants to Earth — revealing the detailed structure of the matter being thrown off the star. The new image, taken by the e-MERLIN radio telescope array operated from the Jodrell Bank Observatory in Cheshire in the United Kingdom, also shows regions of surprisingly hot gas in the star's outer atmosphere and a cooler arc of gas weighing almost as much as the Earth. Betelgeuse is easily visible to the unaided eye as the bright red star on the top left shoulder of Orion the Hunter. The star itself is huge — 1,000 times larger than our Sun
— but at a distance of about 650 light-years, it still appears as a tiny dot in the sky, so to see details of the star and the region surrounding it, astronomers must combine telescopes in arrays. The new image of Betelgeuse shows that its atmosphere extends out to five times the size of the visual surface of the star. It also reveals two hot spots within the outer atmosphere and a faint arc of cool gas even farther out beyond the radio surface of the star. The hot spots appear on opposite sides of Betelgeuse, separated by about half the star’s visual diameter. They have a temperature of about 3700°–4700° Celsius, much higher than the average
Above: Betelgeuse can be found in the top left of the constellation Orion.
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temperature of the star’s radio surface (930° C) and even higher than the 3300° C visual surface. The arc of cool gas lies almost 7.4 billion kilometres away from the star — about the same as Pluto’s farthest distance from the Sun. Scientists estimate the gas has a mass almost two-thirds that of the Earth and a temperature of only – 123° C. Lead researcher Anita Richards from University of Manchester said that it was not yet clear why the hot spots are so hot: "One possibility is that shock waves, caused either by the star pulsating or by convection in its outer layers, are compressing and heating the gas. Another is that the outer atmosphere is patchy and we are seeing through to hotter regions within. The arc of cool gas is thought to be the result of a period of increased mass loss from the star at some point in the last century, but its relationship to structures like the hot spots, which lie much closer in, within the star's outer atmosphere, is unknown." The mechanism by which supergiant stars like Betelgeuse lose matter into space is not well understood despite its key role in the life cycle of matter, enriching the interstellar material from which future stars and planets will form. Detailed high-resolution studies of the regions around massive stars are essential to improving our understanding. Richards added: "Betelgeuse produces a wind equivalent to losing the mass of the Earth every three years, enriched with the chemicals that will go into the next generation of star and planet formation. The full details of how these cool, evolved stars launch their winds is one of the remaining big questions in stellar astronomy.”
Above: In this new image of the outer atmosphere of the red supergiant Betelgeuse, the colours represent brightness ranging from faintest (red) to brightest (white). Driving the point home: Betelgeuse with the orbits of the outer planets on it (from the inside out): Jupiter, Saturn, Uranus, and Neptune.
Continuing research will help scientists determine how elements that are the building blocks of life return to space as well as how close Betelgeuse is to exploding as a supernova. www.astronomy.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.
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Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Hubble telescope breaks record in finding most distant Type Ia Supernova Astronomers just keep honing their skills and refining their techniques to get the most out of their telescopes. Scientists using the Hubble Space Telescope have now broken the record for the most distant Type Ia supernova ever imaged. This supernova is over 10 billion light-years away, with a redshift of 1.914. When this star exploded 10 billion years ago, the Universe was in its early formative years and stars were being born at a rapid rate. “This new distance record holder opens a window into the early Universe, offering important new insights into how these supernovae form,” said astronomer David O. Jones of The Johns Hopkins University in Baltimore, Md., lead author on the science paper detailing the discovery. “At that epoch, we can test theories about how reliable these detonations are for understanding the evolution of the Universe and its expansion.” Designated as SN UDS10Wil (and nicknamed SN Wilson after American President Woodrow Wilson (president from 1913-1921), the distant supernova was part of a three-year Hubble program to survey faraway Type Ia supernovae and determine whether they have changed during the 13.8 billion years since the explosive birth of the universe. Since 2010, the CANDELS+CLASH Supernova Project has uncovered more than 100 supernovae of all types that exploded from 2.4 to over 10 billion years ago. The previous record holder for Type Ia was announced earlier this year, a supernova that exploded around 9 billion years ago and has a redshift of 1.7. Although SN Wilson is only 4 percent more distant than the previous record holder, it pushes roughly 350 million years farther back in time. The most distant supernovae ever are a pair of super-luminous supernovae, at redshifts of 2.05 and 3.90, announced in November 2012. Read about that discovery here. Astronomers took advantage of the
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sharpness and versatility of Hubble’s Wide Field Camera 3 to search for supernovae in nearinfrared light and verify their distance with spectroscopy. These bright beacons are prized by astronomers because they can be used as a yardstick for measuring cosmic distances, thereby yielding clues to the nature of dark energy, the mysterious force accelerating the rate of expansion of the Universe.
Additionally, finding remote supernovae provides a powerful method to measure the universe’s accelerating expansion. “The Type Ia supernovae give us the most precise yardstick ever built, but we’re not quite sure if it always measures exactly a yard,” said team member Steve Rodney of Johns Hopkins University. “The more we understand these supernovae, the more precise our cosmic yardstick will become.” www.universetoday.com
Rain is falling from Saturn’s rings Astronomers have known for years there was water in Saturn’s upper atmosphere. New observations have found water is raining down on Saturn, and it is coming from the planet’s rings. Saturn is the first planet to show significant interaction between its atmosphere and ring system. The main effect of ring rain is that it acts to ‘quench’ the ionosphere of Saturn, severely reducing the electron densities in regions in which it falls. Using the Keck Observatory, researchers found charged water particles falling from the planet’s rings into Saturn’s atmosphere. They also found the extent of the ring-rain is far greater, and falls across larger areas of the planet, than previously thought. The work reveals the rain influences the composition and temperature structure of parts of Saturn’s upper atmosphere. The ring’s effect on electron densities is important because it explains why, for many decades, observations have shown electron densities to be unusually low at some latitudes at Saturn.
In the early 1980s, images from NASA’s Voyager spacecraft showed two to three dark bands on Saturn and scientists theorized that water could have been showering down into those bands from the rings. Then astronomers using ESA’s Infrared Observatory discovered the presence of trace amounts of water in Saturn’s atmosphere back in 1997, but couldn’t really find an explanation for why it was there and how it got there. Then in 2011 observations with the Herschel space observatory determined water ice from geysers on Enceladus formed a giant ring of water vapour around Saturn. But the bands seen by Voyager were not seen again until 2011 as well, when the team observed the planet with Keck Observatory’s NIRSPEC, allowing the observers to clearly see subtle emissions from the bright parts of Saturn.
Recent Events COSMOS 2013 - probably our best ever! COSMOS 2013 took place over the weekend of April 12th to 14th last. And what a weekend it was! This year, Friday night was widely publicised as a family-orientated night, with our guest speaker, Prof. Ian Morison delivering a thoroughly interesting lecture about how NOT to be afraid of black holes! There were kids hampers and a telescope from K-Tec Telescopes as prizes for the raffle that night, which brought in a full house. Below: This is a NASA/ESA Hubble Space Telescope view looking long ago and far away at a supernova that exploded over 10 billion years ago — the most distant Type Ia supernova ever detected. The supernova’s light is just arriving at Earth, having travelled more than 10 billion light-years (redshift 1.914) across space.
The ring rain’s effect occurs in Saturn’s ionosphere where charged particles are produced when the otherwise neutral atmosphere is exposed to a flow of energetic particles or solar radiation. When the scientists tracked the pattern of emissions of a particular hydrogen molecule consisting of three hydrogen atoms they expected to see a uniform planet-wide infrared glow. What they observed instead was a series of light and dark bands with a pattern mimicking the planet’s rings. Saturn’s magnetic field “maps” the water-rich rings and the water-free gaps between rings onto the planet’s atmosphere. “Where Jupiter is glowing evenly across its equatorial regions, Saturn has dark bands where the water is falling in, darkening the ionosphere. We’re now also trying to investigate these features with an instrument on NASA’s Cassini spacecraft. If we’re successful, Cassini may allow us to view in more detail the way that water is removing ionized particles, such as any changes in the altitude or effects that come with the time of day.” www.universetoday.com
Saturday and Sunday were the highlight of the weekend, with speakers delivering top class lectures, exhibits to educate, and even a rocket launch that will be duly added to next year’s programme as a competition! We thank all of our sponsors for their generous donations, and the tremendously hard work the committee put in during the months leading up to COSMOS. COSMOS 2014 dates are confirmed as April 4th to 6th, so mark your diaries now.
April’s Lecture: Quasars & Beyond Seanie Morris presented April 2nd’s talk entitled “Quasars & Beyond: Looking Back in Time”, showing just how hard it is to understand the concept of space-time! He even couldn’t get his head around some of the theories and concepts, and he was the one delivering the talk! Suffice to say that the Universe is around 13.7 billion years old, and will be around for a pretty long time to come. April Lyrids a disappointment This annual Spring meteor shower peaked on the night of April 22nd/23rd, but passed with pretty much little activity. April Lyrids have been disappointing in recent years, with annual rates struggling to meet forecasted ZHRs of around 15 an hour. Go back 20-30 years an you would have expected 20-25 an hour. Our next big meteor shower will be the Perseids on August 12th/13th. More details about them in the June edition of Réalta.
Upcoming Club Events May 7th: Sunspots and Aurora: The Connection” by Laurence Rigney, MAC. May 10th: Outreach Event with the Athlone Girl Guides. Details from the MAC Secretary, you are most welcome to chip in and come along. The first photo of the entire MAC committee since the AGM, the driving force of COSMOS 2013. L-r: Laurence Rigney, Declan Molloy, Dave Connolly, Paul Fitzgerald, Seanie Morris, John Lally, Adrian Waters and Jason Fallon.
May 18th: Observing Session. Weather permitting, at our Clonminch Observing Site. June 4th: “Curious About Mars” by Sean McKenna, MAC. Our lectures take place on the first Tuesday of the month (except July) in the Presbyterian Hall, High Street in Tullamore at 8:00pm. All are welcome to attend, admission is €2.00.
Below: MAC member Dave Connolly took this great image of comet Pan-STARRS using an ioptron skytracker.
Keep an eye out for...
Above: Noctilucent Clouds, these high atmospheric meteorological phenomenae are visible from a narrow band of latitudes with only a window last 6 to 10 weeks centred on June 21st.
Noctilucent Clouds: These high atmospheric meteorological phenomenae are visible from a narrow band of latitudes with only a window last 6 to 10 weeks centred on June 21st. Lying on the outermost edge of our atmosphere, these filament structures catch arced sunlight a couple hours after sunset and shine throughout the night. Thought to be fine dust suspended in the atmosphere covered in ice crystals, the dust itself is believed to be the debris of meteors that burned up on entering the atmosphere. Keep an eye from around an hour or two after sunset from mid May onwards.
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Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Two fine double stars in the Northern Dippers Two of the most famous stars in the far-northern heavens are also superb double stars for small telescopes. If you’re just starting out with a telescope, or if you got out of practice over a long winter, or if you simply wish to visit two old friends, then join in on this mini-tour of these fine stars. And the best news? They couldn’t be easier to find… Our first stop on this mini-tour is the star Mizar, the middle star in the handle of the Big Dipper. Without optics, most observers can barely see a second fainter star about just 1/6 of a degree northeast of Mizar. This 4th-magnitude star is Alcor, which astronomers for decades believed was unassociated with Mizar. Recent measurements, however, suggest it’s loosely bound with the brighter star despite their hefty separation of one light year. Mizar and Alcor were used as a test of vision for young men entering the army in ancient Athens and Sparta. The stars are easily resolved by (modern) younger observers with normal vision. Older stargazers find the pair more challenging. You can find Mizar and the rest of the stars of the Big Dipper by looking high in the northnortheastern sky from April through June. In a small telescope, even at lowest magnification, Mizar and Alcor split cleanly. Now look closer. Mizar has a very close-in companion star some 14? away which becomes visible in a small telescope at 50x or more. Both component stars are themselves unresolved double stars, as is Alcor itself. So the Mizar-Alcor system consists of a total of six stars. The group is about 78 light years away and belong to the Ursa Major Moving Group, a new group of associated stars that makes up most of the stars of the Big Dipper. Halfway between Mizar and Alcor and just off the centre line between them lies an 8th-magnitude star. It’s an unremarkable star, but an 18thcentury German astronomer named Johann Liebknecht caused quite a stir when he announced this star was in fact a newly discovered planet, which he named Sidus Ludoviciana (“Ludwig’s Star”) after
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the German king. He was wrong of course. This is no planet, just star which is aligned by chance, but unassociated, with Mizar and Alcor. Now to the second double star of the tour… Polaris, the North Star. Yes, the North Star is a pleasing double star for a small scope, with the 2nd magnitude primary separated by 18” from a 9thmagnitude secondary. That’s a generous separation, but the large difference in brightness makes for a modest challenge in picking the fainter star out of the glare of the primary. Try 50x or more to put some dark sky between the two. Polaris also lies on the circumference of a lovely nearcircular group of stars called the “Engagement Ring”, a group so-
named because Polaris appears as a diamond in a band of fainter 9thmagnitude stars. This unmistakable group is about half a degree in diameter, easily visible at low magnification in a telescope. Polaris is also a variable star, a Cepheid variable, in fact, which changes brightness from magnitude
1.9 to 2.1 over a period of nearly 4 days. Astronomers use Cepheid variables in other galaxies to determine the distance scale of the nearby universe. So Polaris, as one of the nearest Cepheids, is heavily studied by astronomers. www.oneminuteastronomer.com
Dark Matter signals recorded in Minnesota mine More hints of dark matter have emerged from the Cryogenic Dark sources. The three possible WIMP events popped out of data in which Matter Search (CDMS), which hunts for the theorized particles 0.7 similar events would be from the depths of a mine in Minnesota. Eight silicon detectors recorded three events that may represent collisions from weakly interacting massive particles, or WIMPs. Physicists have found hints of the existence of WIMPs before, but they remain elusive. Two other possible detections from the CDMS search, reported in 2010, turned out to be indistinguishable from background collisions from other, non-WIMP, sources. The same may yet hold true for the latest findings. The work was reported on 13 April at the American Physical Society meeting in Denver. “We do not believe this result rises to the level of a discovery, but it does call for further investigation. CDMS-II, the second generation of the search,
ran between 2003 and 2008. The earlier WIMP suspects were spotted in its 19 germanium detectors. The new work comes from a subset of its 11 silicon detectors, which are more sensitive than germanium to collisions from low-energy particles. Cooled to a temperature of just 40 millikelvins, the CDMS-II detectors sense heat given off when a particle collides with one of their crystals. The challenge is distinguishing a possible WIMP collision from the many collisions of other particles, such as neutrons. The CDMS tries to get around that by shielding its detectors as much as possible and by precisely calculating the rate of expected collisions from other, background
expected from background, McCarthy said. Two of them occurred in the same detector.
He reported the signal at a 99.81% confidence level, or around three sigma in statistical language. “We favor the WIMP plus background hypothesis,” he said. But the CDMS-II result would imply a WIMP with a mass of 8.6 gigaelectronvolts, far lighter than physicists might expect. The experiment’s successor, SuperCDMS, is now running in the Soudan mine and may yet yield more insight. www.scientificamerican.com
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Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Saturn's moons: Facts about the ringed planet's satellites Sixty-two moons travel around Saturn. They come in a variety of sizes and compositions, from almost pure ice to rocky material, as well as a combination of both. Their journeys around the ringed planet average from half an Earth day to just over four Earth years. Saturn's moons formed early in the history of the solar system. One of the moons, Titan, makes up 96 percent of the mass orbiting the planet. Scientists think that the system may have originally housed two such moons, but the second broke up, creating the debris that formed the rings and smaller, inner moons. Another theory suggests that the system originally housed several large moons, similar to Jupiter's Galilean moons, but two fused into Titan. The violent collision could have scattered the debris that would have later drawn together into the smaller moons.
discovery of the rest.
Some of the moons travel inside the gaps of the rings, clearing paths through the debris. Others orbit farther out. Several of the moons interact with one another, affecting their orbits. Larger moons may trap smaller moons, keeping them nearby. Sixteen of the moons are tidally locked, with one face permanently turned toward Saturn.
Let's look at the eight major moons of Saturn:
The first moon was discovered in 1655. Over the next 200 years, the other seven major satellites were spotted. By 1997, astronomers on Earth had found 18 moons in orbit around the planet. The close orbit of NASA's Cassini mission, along with advances in technology for Earthbased telescopes, enabled the
In 1847, British astronomer Sir John Herschel suggested that the moons of Saturn take their names from the Titans. The mythical siblings of the Greek god Cronus — Saturn to the Romans — the Titans battled the Olympian gods and lost. Once the names of the Titans were used, the moons began to be called after other characters from Roman and Greek mythology. Only 53 of Saturn's moons have names; the rest are identified by a numerical designation relating to their year of discovery.
Titan Titan is the largest of Saturn's moons and the first to be discovered. Titan is the only moon in the solar system known to have
resembles an elongated potato rather than a sphere, a form that may have been created when an impact demolished a larger moon long ago. Hyperion has a spongy shape, possibly due to its low density and porous surface. Impacts seem to be absorbed by the moon, and most of the ejecta is thrown into space. a significant atmosphere. Nitrogen and methane extend around the moon 10 times as far into space as Earth's atmosphere, sometimes falling to the surface in the form of methane rain. This atmosphere makes it one of the best potential candidates for hosting life. Titan is larger than the planet Mercury, though not nearly as massive. Dione Dione is thought to be a dense rocky core surrounded by waterice. The tidally locked moon is heavily cratered not on its leading side but on its back side. Astronomers think a collision could
have spun the moon on its axis. Enceladus Enceladus contains more than 70 geysers at its south pole. Tidal heating causes portions of the icy planet to melt, spewing icy material
Iapetus Iapetus features light and dark contrasts on its surface, giving the moon a yin-yang shape. Dark hydrocarbons falling to the moon long ago, perhaps from the nearby moon Phoebe, may have had more time to absorb more heat, gradually growing and spreading over time. Iapetus has a walnut-like shape, with its center bulging outward,
into space from its "tiger stripes." The tiny bits of ice travel together to create Saturn's E ring. The satellite's icy surface makes it one of the brightest objects in the solar system. Hyperion Hyperion was the last of the major satellites to be discovered. Hyperion is a small moon with an irregular appearance. The flattened object
and a ridge running around its equator. The moon also contains some of the highest mountains in the solar system. Mimas Mimas has a gaping crater that gives the rocky moon a strong resemblance to fictional Death Star in the "Star Wars" movies. The impact stands out despite the fact that Mimas is one of the most heavily cratered bodies in the solar system, with overlapping impacts covering the surface. The smallest and closest orbiting of Saturn's major moons, Mimas cleared the gap known as the Cassini division between two of the planet's rings.
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known oxygen atmosphere in the solar system. Radiation from Saturn's magnetosphere could release oxygen and carbon dioxide from the icy surface.
Mimas is made up primarily of water-ice, but despite its proximity to the planet (and the resulting tidal heating that should occur), the surface of the moon remains unchanged; none of the ice seems to be melting, though such melting occurs on other, more distant moons.
Tethys Tethys travels close to Saturn and feels the gravitational pull of the planet. The heat from Saturn may allow the moon's icy surface to melt slightly, filling in craters and other signs of impact. Made up almost entirely of water ice, the surface is highly reflective. A large trench crosses the moon, running diagonally from its north to south pole and spanning three-quarters of the satellite's circumference. A
large crater on the other side of the moon covers nearly two-fifth of the moon's diameter and is nearly the size of Mimas. www.space.com
Rhea Rhea is a heavily cratered moon and lacks a core at its center. Instead, the entire body is composed of ice, with traces of rock mixed in, causing it to resemble a dirty snowball. The second largest of the planet's major moons, Rhea is still rather small, about half the size of Earth's moon. The satellite contains a faint oxygen atmosphere, about 5 trillion times less dense than the one found on Earth, but the only
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Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Saturn's moons: Facts about the ringed planet's satellites Sixty-two moons travel around Saturn. They come in a variety of sizes and compositions, from almost pure ice to rocky material, as well as a combination of both. Their journeys around the ringed planet average from half an Earth day to just over four Earth years. Saturn's moons formed early in the history of the solar system. One of the moons, Titan, makes up 96 percent of the mass orbiting the planet. Scientists think that the system may have originally housed two such moons, but the second broke up, creating the debris that formed the rings and smaller, inner moons. Another theory suggests that the system originally housed several large moons, similar to Jupiter's Galilean moons, but two fused into Titan. The violent collision could have scattered the debris that would have later drawn together into the smaller moons.
discovery of the rest.
Some of the moons travel inside the gaps of the rings, clearing paths through the debris. Others orbit farther out. Several of the moons interact with one another, affecting their orbits. Larger moons may trap smaller moons, keeping them nearby. Sixteen of the moons are tidally locked, with one face permanently turned toward Saturn.
Let's look at the eight major moons of Saturn:
The first moon was discovered in 1655. Over the next 200 years, the other seven major satellites were spotted. By 1997, astronomers on Earth had found 18 moons in orbit around the planet. The close orbit of NASA's Cassini mission, along with advances in technology for Earthbased telescopes, enabled the
In 1847, British astronomer Sir John Herschel suggested that the moons of Saturn take their names from the Titans. The mythical siblings of the Greek god Cronus — Saturn to the Romans — the Titans battled the Olympian gods and lost. Once the names of the Titans were used, the moons began to be called after other characters from Roman and Greek mythology. Only 53 of Saturn's moons have names; the rest are identified by a numerical designation relating to their year of discovery.
Titan Titan is the largest of Saturn's moons and the first to be discovered. Titan is the only moon in the solar system known to have
resembles an elongated potato rather than a sphere, a form that may have been created when an impact demolished a larger moon long ago. Hyperion has a spongy shape, possibly due to its low density and porous surface. Impacts seem to be absorbed by the moon, and most of the ejecta is thrown into space. a significant atmosphere. Nitrogen and methane extend around the moon 10 times as far into space as Earth's atmosphere, sometimes falling to the surface in the form of methane rain. This atmosphere makes it one of the best potential candidates for hosting life. Titan is larger than the planet Mercury, though not nearly as massive. Dione Dione is thought to be a dense rocky core surrounded by waterice. The tidally locked moon is heavily cratered not on its leading side but on its back side. Astronomers think a collision could
have spun the moon on its axis. Enceladus Enceladus contains more than 70 geysers at its south pole. Tidal heating causes portions of the icy planet to melt, spewing icy material
Iapetus Iapetus features light and dark contrasts on its surface, giving the moon a yin-yang shape. Dark hydrocarbons falling to the moon long ago, perhaps from the nearby moon Phoebe, may have had more time to absorb more heat, gradually growing and spreading over time. Iapetus has a walnut-like shape, with its center bulging outward,
into space from its "tiger stripes." The tiny bits of ice travel together to create Saturn's E ring. The satellite's icy surface makes it one of the brightest objects in the solar system. Hyperion Hyperion was the last of the major satellites to be discovered. Hyperion is a small moon with an irregular appearance. The flattened object
and a ridge running around its equator. The moon also contains some of the highest mountains in the solar system. Mimas Mimas has a gaping crater that gives the rocky moon a strong resemblance to fictional Death Star in the "Star Wars" movies. The impact stands out despite the fact that Mimas is one of the most heavily cratered bodies in the solar system, with overlapping impacts covering the surface. The smallest and closest orbiting of Saturn's major moons, Mimas cleared the gap known as the Cassini division between two of the planet's rings.
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known oxygen atmosphere in the solar system. Radiation from Saturn's magnetosphere could release oxygen and carbon dioxide from the icy surface.
Mimas is made up primarily of water-ice, but despite its proximity to the planet (and the resulting tidal heating that should occur), the surface of the moon remains unchanged; none of the ice seems to be melting, though such melting occurs on other, more distant moons.
Tethys Tethys travels close to Saturn and feels the gravitational pull of the planet. The heat from Saturn may allow the moon's icy surface to melt slightly, filling in craters and other signs of impact. Made up almost entirely of water ice, the surface is highly reflective. A large trench crosses the moon, running diagonally from its north to south pole and spanning three-quarters of the satellite's circumference. A
large crater on the other side of the moon covers nearly two-fifth of the moon's diameter and is nearly the size of Mimas. www.space.com
Rhea Rhea is a heavily cratered moon and lacks a core at its center. Instead, the entire body is composed of ice, with traces of rock mixed in, causing it to resemble a dirty snowball. The second largest of the planet's major moons, Rhea is still rather small, about half the size of Earth's moon. The satellite contains a faint oxygen atmosphere, about 5 trillion times less dense than the one found on Earth, but the only
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Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Two fine double stars in the Northern Dippers Two of the most famous stars in the far-northern heavens are also superb double stars for small telescopes. If you’re just starting out with a telescope, or if you got out of practice over a long winter, or if you simply wish to visit two old friends, then join in on this mini-tour of these fine stars. And the best news? They couldn’t be easier to find… Our first stop on this mini-tour is the star Mizar, the middle star in the handle of the Big Dipper. Without optics, most observers can barely see a second fainter star about just 1/6 of a degree northeast of Mizar. This 4th-magnitude star is Alcor, which astronomers for decades believed was unassociated with Mizar. Recent measurements, however, suggest it’s loosely bound with the brighter star despite their hefty separation of one light year. Mizar and Alcor were used as a test of vision for young men entering the army in ancient Athens and Sparta. The stars are easily resolved by (modern) younger observers with normal vision. Older stargazers find the pair more challenging. You can find Mizar and the rest of the stars of the Big Dipper by looking high in the northnortheastern sky from April through June. In a small telescope, even at lowest magnification, Mizar and Alcor split cleanly. Now look closer. Mizar has a very close-in companion star some 14? away which becomes visible in a small telescope at 50x or more. Both component stars are themselves unresolved double stars, as is Alcor itself. So the Mizar-Alcor system consists of a total of six stars. The group is about 78 light years away and belong to the Ursa Major Moving Group, a new group of associated stars that makes up most of the stars of the Big Dipper. Halfway between Mizar and Alcor and just off the centre line between them lies an 8th-magnitude star. It’s an unremarkable star, but an 18thcentury German astronomer named Johann Liebknecht caused quite a stir when he announced this star was in fact a newly discovered planet, which he named Sidus Ludoviciana (“Ludwig’s Star”) after
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the German king. He was wrong of course. This is no planet, just star which is aligned by chance, but unassociated, with Mizar and Alcor. Now to the second double star of the tour… Polaris, the North Star. Yes, the North Star is a pleasing double star for a small scope, with the 2nd magnitude primary separated by 18” from a 9thmagnitude secondary. That’s a generous separation, but the large difference in brightness makes for a modest challenge in picking the fainter star out of the glare of the primary. Try 50x or more to put some dark sky between the two. Polaris also lies on the circumference of a lovely nearcircular group of stars called the “Engagement Ring”, a group so-
named because Polaris appears as a diamond in a band of fainter 9thmagnitude stars. This unmistakable group is about half a degree in diameter, easily visible at low magnification in a telescope. Polaris is also a variable star, a Cepheid variable, in fact, which changes brightness from magnitude
1.9 to 2.1 over a period of nearly 4 days. Astronomers use Cepheid variables in other galaxies to determine the distance scale of the nearby universe. So Polaris, as one of the nearest Cepheids, is heavily studied by astronomers. www.oneminuteastronomer.com
Dark Matter signals recorded in Minnesota mine More hints of dark matter have emerged from the Cryogenic Dark sources. The three possible WIMP events popped out of data in which Matter Search (CDMS), which hunts for the theorized particles 0.7 similar events would be from the depths of a mine in Minnesota. Eight silicon detectors recorded three events that may represent collisions from weakly interacting massive particles, or WIMPs. Physicists have found hints of the existence of WIMPs before, but they remain elusive. Two other possible detections from the CDMS search, reported in 2010, turned out to be indistinguishable from background collisions from other, non-WIMP, sources. The same may yet hold true for the latest findings. The work was reported on 13 April at the American Physical Society meeting in Denver. “We do not believe this result rises to the level of a discovery, but it does call for further investigation. CDMS-II, the second generation of the search,
ran between 2003 and 2008. The earlier WIMP suspects were spotted in its 19 germanium detectors. The new work comes from a subset of its 11 silicon detectors, which are more sensitive than germanium to collisions from low-energy particles. Cooled to a temperature of just 40 millikelvins, the CDMS-II detectors sense heat given off when a particle collides with one of their crystals. The challenge is distinguishing a possible WIMP collision from the many collisions of other particles, such as neutrons. The CDMS tries to get around that by shielding its detectors as much as possible and by precisely calculating the rate of expected collisions from other, background
expected from background, McCarthy said. Two of them occurred in the same detector.
He reported the signal at a 99.81% confidence level, or around three sigma in statistical language. “We favor the WIMP plus background hypothesis,” he said. But the CDMS-II result would imply a WIMP with a mass of 8.6 gigaelectronvolts, far lighter than physicists might expect. The experiment’s successor, SuperCDMS, is now running in the Soudan mine and may yet yield more insight. www.scientificamerican.com
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Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Hubble telescope breaks record in finding most distant Type Ia Supernova Astronomers just keep honing their skills and refining their techniques to get the most out of their telescopes. Scientists using the Hubble Space Telescope have now broken the record for the most distant Type Ia supernova ever imaged. This supernova is over 10 billion light-years away, with a redshift of 1.914. When this star exploded 10 billion years ago, the Universe was in its early formative years and stars were being born at a rapid rate. “This new distance record holder opens a window into the early Universe, offering important new insights into how these supernovae form,” said astronomer David O. Jones of The Johns Hopkins University in Baltimore, Md., lead author on the science paper detailing the discovery. “At that epoch, we can test theories about how reliable these detonations are for understanding the evolution of the Universe and its expansion.” Designated as SN UDS10Wil (and nicknamed SN Wilson after American President Woodrow Wilson (president from 1913-1921), the distant supernova was part of a three-year Hubble program to survey faraway Type Ia supernovae and determine whether they have changed during the 13.8 billion years since the explosive birth of the universe. Since 2010, the CANDELS+CLASH Supernova Project has uncovered more than 100 supernovae of all types that exploded from 2.4 to over 10 billion years ago. The previous record holder for Type Ia was announced earlier this year, a supernova that exploded around 9 billion years ago and has a redshift of 1.7. Although SN Wilson is only 4 percent more distant than the previous record holder, it pushes roughly 350 million years farther back in time. The most distant supernovae ever are a pair of super-luminous supernovae, at redshifts of 2.05 and 3.90, announced in November 2012. Read about that discovery here. Astronomers took advantage of the
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sharpness and versatility of Hubble’s Wide Field Camera 3 to search for supernovae in nearinfrared light and verify their distance with spectroscopy. These bright beacons are prized by astronomers because they can be used as a yardstick for measuring cosmic distances, thereby yielding clues to the nature of dark energy, the mysterious force accelerating the rate of expansion of the Universe.
Additionally, finding remote supernovae provides a powerful method to measure the universe’s accelerating expansion. “The Type Ia supernovae give us the most precise yardstick ever built, but we’re not quite sure if it always measures exactly a yard,” said team member Steve Rodney of Johns Hopkins University. “The more we understand these supernovae, the more precise our cosmic yardstick will become.” www.universetoday.com
Rain is falling from Saturn’s rings Astronomers have known for years there was water in Saturn’s upper atmosphere. New observations have found water is raining down on Saturn, and it is coming from the planet’s rings. Saturn is the first planet to show significant interaction between its atmosphere and ring system. The main effect of ring rain is that it acts to ‘quench’ the ionosphere of Saturn, severely reducing the electron densities in regions in which it falls. Using the Keck Observatory, researchers found charged water particles falling from the planet’s rings into Saturn’s atmosphere. They also found the extent of the ring-rain is far greater, and falls across larger areas of the planet, than previously thought. The work reveals the rain influences the composition and temperature structure of parts of Saturn’s upper atmosphere. The ring’s effect on electron densities is important because it explains why, for many decades, observations have shown electron densities to be unusually low at some latitudes at Saturn.
In the early 1980s, images from NASA’s Voyager spacecraft showed two to three dark bands on Saturn and scientists theorized that water could have been showering down into those bands from the rings. Then astronomers using ESA’s Infrared Observatory discovered the presence of trace amounts of water in Saturn’s atmosphere back in 1997, but couldn’t really find an explanation for why it was there and how it got there. Then in 2011 observations with the Herschel space observatory determined water ice from geysers on Enceladus formed a giant ring of water vapour around Saturn. But the bands seen by Voyager were not seen again until 2011 as well, when the team observed the planet with Keck Observatory’s NIRSPEC, allowing the observers to clearly see subtle emissions from the bright parts of Saturn.
Recent Events COSMOS 2013 - probably our best ever! COSMOS 2013 took place over the weekend of April 12th to 14th last. And what a weekend it was! This year, Friday night was widely publicised as a family-orientated night, with our guest speaker, Prof. Ian Morison delivering a thoroughly interesting lecture about how NOT to be afraid of black holes! There were kids hampers and a telescope from K-Tec Telescopes as prizes for the raffle that night, which brought in a full house. Below: This is a NASA/ESA Hubble Space Telescope view looking long ago and far away at a supernova that exploded over 10 billion years ago — the most distant Type Ia supernova ever detected. The supernova’s light is just arriving at Earth, having travelled more than 10 billion light-years (redshift 1.914) across space.
The ring rain’s effect occurs in Saturn’s ionosphere where charged particles are produced when the otherwise neutral atmosphere is exposed to a flow of energetic particles or solar radiation. When the scientists tracked the pattern of emissions of a particular hydrogen molecule consisting of three hydrogen atoms they expected to see a uniform planet-wide infrared glow. What they observed instead was a series of light and dark bands with a pattern mimicking the planet’s rings. Saturn’s magnetic field “maps” the water-rich rings and the water-free gaps between rings onto the planet’s atmosphere. “Where Jupiter is glowing evenly across its equatorial regions, Saturn has dark bands where the water is falling in, darkening the ionosphere. We’re now also trying to investigate these features with an instrument on NASA’s Cassini spacecraft. If we’re successful, Cassini may allow us to view in more detail the way that water is removing ionized particles, such as any changes in the altitude or effects that come with the time of day.” www.universetoday.com
Saturday and Sunday were the highlight of the weekend, with speakers delivering top class lectures, exhibits to educate, and even a rocket launch that will be duly added to next year’s programme as a competition! We thank all of our sponsors for their generous donations, and the tremendously hard work the committee put in during the months leading up to COSMOS. COSMOS 2014 dates are confirmed as April 4th to 6th, so mark your diaries now.
April’s Lecture: Quasars & Beyond Seanie Morris presented April 2nd’s talk entitled “Quasars & Beyond: Looking Back in Time”, showing just how hard it is to understand the concept of space-time! He even couldn’t get his head around some of the theories and concepts, and he was the one delivering the talk! Suffice to say that the Universe is around 13.7 billion years old, and will be around for a pretty long time to come. April Lyrids a disappointment This annual Spring meteor shower peaked on the night of April 22nd/23rd, but passed with pretty much little activity. April Lyrids have been disappointing in recent years, with annual rates struggling to meet forecasted ZHRs of around 15 an hour. Go back 20-30 years an you would have expected 20-25 an hour. Our next big meteor shower will be the Perseids on August 12th/13th. More details about them in the June edition of Réalta.
Upcoming Club Events May 7th: Sunspots and Aurora: The Connection” by Laurence Rigney, MAC. May 10th: Outreach Event with the Athlone Girl Guides. Details from the MAC Secretary, you are most welcome to chip in and come along. The first photo of the entire MAC committee since the AGM, the driving force of COSMOS 2013. L-r: Laurence Rigney, Declan Molloy, Dave Connolly, Paul Fitzgerald, Seanie Morris, John Lally, Adrian Waters and Jason Fallon.
May 18th: Observing Session. Weather permitting, at our Clonminch Observing Site. June 4th: “Curious About Mars” by Sean McKenna, MAC. Our lectures take place on the first Tuesday of the month (except July) in the Presbyterian Hall, High Street in Tullamore at 8:00pm. All are welcome to attend, admission is €2.00.
Below: MAC member Dave Connolly took this great image of comet Pan-STARRS using an ioptron skytracker.
Keep an eye out for...
Above: Noctilucent Clouds, these high atmospheric meteorological phenomenae are visible from a narrow band of latitudes with only a window last 6 to 10 weeks centred on June 21st.
Noctilucent Clouds: These high atmospheric meteorological phenomenae are visible from a narrow band of latitudes with only a window last 6 to 10 weeks centred on June 21st. Lying on the outermost edge of our atmosphere, these filament structures catch arced sunlight a couple hours after sunset and shine throughout the night. Thought to be fine dust suspended in the atmosphere covered in ice crystals, the dust itself is believed to be the debris of meteors that burned up on entering the atmosphere. Keep an eye from around an hour or two after sunset from mid May onwards.
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Midlands Astronomy Club Magazine
Kid’s Korner Why is the Sky Blue?
Like energy passing through the ocean, light energy travels in waves, too. Some light travels in short, "choppy" waves. Other light travels in long, lazy waves. Blue It is easy to see that the sky is blue. light waves are shorter than red Have you ever wondered why? A lot light waves. of other smart people have, and it took a long time to figure it out! All light travels in a straight line unless something gets in the way The light from the Sun looks white. to: But it is really made up of all the colours of the rainbow. • reflect it (like a mirror)
• bend it (like a prism) A prism is a specially shaped crystal. When white light shines • or scatter it (like molecules of the gases in the atmosphere) through a prism, the light is separated into all its colours. The light you see is just one tiny bit of all the kinds of light energy S u n l i g h t r e a c h e s E a r t h ' s beaming around the Universe--and atmosphere and is scattered in all directions by all the gases around you! and particles in the air. Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colours because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.
Closer to the horizon, the sky fades to a lighter blue or white. The sunlight reaching us from low in the sky has passed through even more air than the sunlight reaching us from overhead. As the sunlight has passed through all this air, the air molecules have scattered and rescattered the blue light many times in many directions. Also, the surface of Earth has reflected and scattered the light. All this scattering mixes the colours together again so we see more white and less blue.
Midlands Astronomy Club Magazine What Makes a Red Sunset? As the Sun gets lower in the sky, its light is passing through more of the atmosphere to reach you. Even more of the blue light is scattered, allowing the reds and yellows to pass straight through to your eyes. Sometimes the whole western sky seems to glow. The sky appears red because larger particles of dust, pollution, and water vapour in the atmosphere reflect and scatter more of the reds and yellows. Why Does Light Scattering Matter? How much of the Sun's light gets bounced around in Earth's atmosphere and how much gets reflected back into space? How much light gets soaked up by land and water, asphalt freeways and sunburned surfers? How much light do water and clouds reflect back into space? And why do we care? Sunlight carries the energy that heats Earth and powers all life on Earth. Our climate is affected by how sunlight is scattered by forests, deserts, snow- and ice-covered surfaces, different types of clouds, smoke from forest fires, and other pollutants in the air.
Mysterious hot spots observed in Betelgeuse A new image of Betelgeuse, a nearby red supergiant, shows it has both hot spots and a giant arc of cool gas extending far beyond its atmosphere. Astronomers have released a new image of the outer atmosphere of Betelgeuse — one of the nearest red supergiants to Earth — revealing the detailed structure of the matter being thrown off the star. The new image, taken by the e-MERLIN radio telescope array operated from the Jodrell Bank Observatory in Cheshire in the United Kingdom, also shows regions of surprisingly hot gas in the star's outer atmosphere and a cooler arc of gas weighing almost as much as the Earth. Betelgeuse is easily visible to the unaided eye as the bright red star on the top left shoulder of Orion the Hunter. The star itself is huge — 1,000 times larger than our Sun
— but at a distance of about 650 light-years, it still appears as a tiny dot in the sky, so to see details of the star and the region surrounding it, astronomers must combine telescopes in arrays. The new image of Betelgeuse shows that its atmosphere extends out to five times the size of the visual surface of the star. It also reveals two hot spots within the outer atmosphere and a faint arc of cool gas even farther out beyond the radio surface of the star. The hot spots appear on opposite sides of Betelgeuse, separated by about half the star’s visual diameter. They have a temperature of about 3700°–4700° Celsius, much higher than the average
Above: Betelgeuse can be found in the top left of the constellation Orion.
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temperature of the star’s radio surface (930° C) and even higher than the 3300° C visual surface. The arc of cool gas lies almost 7.4 billion kilometres away from the star — about the same as Pluto’s farthest distance from the Sun. Scientists estimate the gas has a mass almost two-thirds that of the Earth and a temperature of only – 123° C. Lead researcher Anita Richards from University of Manchester said that it was not yet clear why the hot spots are so hot: "One possibility is that shock waves, caused either by the star pulsating or by convection in its outer layers, are compressing and heating the gas. Another is that the outer atmosphere is patchy and we are seeing through to hotter regions within. The arc of cool gas is thought to be the result of a period of increased mass loss from the star at some point in the last century, but its relationship to structures like the hot spots, which lie much closer in, within the star's outer atmosphere, is unknown." The mechanism by which supergiant stars like Betelgeuse lose matter into space is not well understood despite its key role in the life cycle of matter, enriching the interstellar material from which future stars and planets will form. Detailed high-resolution studies of the regions around massive stars are essential to improving our understanding. Richards added: "Betelgeuse produces a wind equivalent to losing the mass of the Earth every three years, enriched with the chemicals that will go into the next generation of star and planet formation. The full details of how these cool, evolved stars launch their winds is one of the remaining big questions in stellar astronomy.”
Above: In this new image of the outer atmosphere of the red supergiant Betelgeuse, the colours represent brightness ranging from faintest (red) to brightest (white). Driving the point home: Betelgeuse with the orbits of the outer planets on it (from the inside out): Jupiter, Saturn, Uranus, and Neptune.
Continuing research will help scientists determine how elements that are the building blocks of life return to space as well as how close Betelgeuse is to exploding as a supernova. www.astronomy.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.
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Midlands Astronomy Club Magazine
Saturn's moons: Facts about the ringed planet's satellites ...... 6 Two fine double stars in the Northern Dippers ...................... 8
Club News Club news ........................................................................... 9
Kids Korner ....................................................................... 10
Sculpted by stellar winds and radiation, the star factory known as Messier 17 (Omega Nebula or the Swan Nebula) lies some 5,500 light-years away in the nebula-rich constellation Sagittarius and spans almost 100 light-years. The sharp, composite, colour image utilizing data from space and ground based telescopes, follows faint details of the region's gas and dust clouds against a backdrop of the Milky Way. Stellar winds and energetic light from hot, massive stars formed from M17's stock of cosmic gas and dust have slowly carved away at the remaining interstellar material producing the cavernous appearance and undulating shapes.
Credit & Copyright: Subaru Telescope (NAOJ), HST, Colour data: Wolfgang Promper, Processing: Robert Gendler
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Methane Giants Class N Reducing Planets Minshara Class Ice Giants
Dark Matter signals recorded in Minnesota mine.................... 8
Kids Section Front cover image:
2. What class of planets does Neptune and Uranus belong to?
Quizzes and Games Exercise your brain ............................................................ 11
Monthly Sky Guide Beginners sky guide for this month .................................... 12
Internet Highlights Special content only available with the online version of the magazine ................................................................ 13
3. Which of the following is NOT true of the all gas giants in our solar system? They all have many moons. They all have ring systems. They all lack a solid surface. They all generate less energy than they take in from the sun. 4. The first extrasolar planet was discovered in 1992. What type of planet was discovered at this time? a a a a
brown dwarf gas giant rocky planet Hot Neptune
5. The precise size of a gas giant can be determined by which of the following planet-finding techniques? wobble method
Their mass is close to the size of Jupiter or larger. They orbit their parent star at a distance of between .015 and 0.5 astronomical units. They most likely formed at their present location in relation to their host star. They have a greater chance of transiting their host star. 7. Some extrasolar gas giants are thought to have migrated to the edge of their solar systems by which type of resonance? Laplace resonance secular resonance Linblad resonance mean motion orbital resonance 8. One type of Jovian planet has a very unusual orbit as well as a very large mass. The presence of this type of planet may cause Earthlike planets to be moved out of the habitable zone of its host star. What are these planets called? Eccentric Jupiters Elliptical Giants Puffy Planets Radical Giants
9 1
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8
1
7
4 5
2
8
9 6
6
8
1
8
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9
5
4 9
5
2 7
Check your answers
Answer 5. The correct answer was transit technique. The transit technique is one in which the observed planet transits or passes directly in front of its home star with respect to the earth. This enables scientists to determine its size.
per hour! ............................................................................ 5
3 6. Which of the following is NOT true of hot Jupiters?
Answer 1. The correct answer was hydrogen and helium. Gas Giants are often called Jovian planets, named after Jupiter, a classic example of a gas giant, although there is a lot of variety among this class of planets.
You can see more about the club and its events on www.midlandsastronomy.com or contact the club via e-mail at midlandsastronomy@gmail.com Meetings are informal and are aimed at a level to suit all ages.
Black Hole flings companion star at 2,000,000 Kilometres
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Answer 2. The correct answer was Ice Giants. Methane is the component that gives Neptune and Uranus their blue colour.
Rain is falling from Saturn’s rings ......................................... 4
hydrogen and methane oxygen and carbon dioxide hydrogen and helium nitrogen and hydrogen
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Answer 6. The correct answer was They most likely formed at their present location in relation to their host star. It is thought that Hot Jupiters migrated from a distance farther out from their host sun to their present location because there would not have been enough material in that close proximity to a star for a planet of such a large size to have formed. One astronomical unit is equal to the distance from the Earth to the sun.
Type Ia Supernova .............................................................. 4
SUDOKU
Answer 3. The correct answer was They all generate less energy than they take in from the sun. Jupiter produces more heat than it receives from the sun. This is thought to be because its "surface" is cooling, which causes compression of its layers resulting in heat production. This is called the KelvinHelmholtz mechanism. Saturn seems to do the same, but it is not certain as to whether the heat production is as great or not. All four of the gas giants in our solar system have rings as well as many moons, from as few as eight to almost twenty.
Hubble telescope breaks record in finding most distant
gravitational microlensing radial velocity technique transit technique
Answer 7. The correct answer was mean motion orbital resonance. The gravitational pull of the orbits of the two planets gradually move them further out. Some believe that it is possible that the mean motion orbital resonance between Jupiter and Saturn caused a gravitational push that sent Uranus and Neptune into higher orbits. This gives new meaning to the term "Dancing With the Stars".
Mysterious hot spots observed in Betelgeuse ........................ 3
1. Two gases make up the main components of Jupiter and Saturn. What are they?
Answer 8. The correct answer was Eccentric Jupiters. Eccentric Jupiters often have an elliptical orbit, like comets. One source sited reported that approximately 7% of the exoplanets are of this type. As research continues that percentage will possibly change.
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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 Saturday of every month..
Exercise your brain
contents
Answer 4. The correct answer was a rocky planet. Actually it was a pair of rocky planets that was discovered in 1992 by two radio astronomers (Aleksander Wolszczan and Dale Frail) and this discovery was quickly confirmed. They were orbiting a star in the constellation Virgo, located 980 light-years from the Earth. The first gas giant was discovered by Michel Mayor and Didier Queloz of the University of Geneva in 1995; it was named 51 Pegasi B-Bellerphon.
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 May General notes May presents some wonderful observing opportunities this year. Starting off with the naked eye, There are two showers this month. The first shower is the Eta Aquarids which peaks on the morning of the 6th. The predictions for this shower vary between 40 and 85. These are typically fast, bright meteors and are of a similar speed to the Perseids. Some will leave persistent trains. However it is not a well placed shower for us. The radiant only rises at 04:00, however on a positive note, there will be no lunar interference. The second shower this month is a minor one. They are the Eta Lyrids, peaking on the 9th with a ZHR of 3. There will be some lunar interference with first quarter moon in the night sky.
Telescope Targets Many of March's and April's targets are still available for viewing. See those month's picks for these targets. We'll add a couple of globular clusters to our hunt this month. M3 in Cane Venatici is one of the brightest globulars in the sky (along with M13 and Omega Centauri). To find M3, use the end star of the big dipper's handle (Alkaid) and the very bright star Arcturus.
Issue 43 - May, 2013
About halfway between these 2 stars and slightly to the west is a dimmer star called Beta Comae. Place Beta Comea at the edge of your finder's FOV (moving to the east), at this point, M3 should be at the opposite edge of the finderscope field. Centre M3 and enjoy the view! Don't be afraid to increase the power on this one and see how many individual stars you can pick out. The good news is that M3 should be bright enough to be seen even from moderately light polluted locations, the bad news is that Beta Comea will be invisible to hop from. I've managed to find M3 by using Alkaid and Arcturus and scanning the area halfway between them with the scope at low power (albeit somewhat challenging). M3 contains as many a 500,000 stars packed into an area of space approximately 200 Lightyears in diameter. It is located approximately 40,000 light-years from us and it's age is estimated at 10 - 15 billion years old. M53 is another globular cluster which is located in the constellation Coma Berenices. Using Arcturus and a much dimmer star just to the west (Muphrid) as our distance measure go approximately twice this distance and slightly north to M53. M53 will take somewhat darker skies to locate than M3.
M53 contains approximately 100,000 stars spanning about 300 light-years across. It is located approximately 65,000 light-years from us. Also in Coma Berenices is a fairly bright galaxy, M64 (The Blackeye Galaxy). Just north (up from) of M53 is M64 (about the same distance as the distance between Arcturus and Muphrid. Distance estimates to this Spiral Galaxy range from 10 - 40 million lightyears. The size estimates for this one range from 25,000 to 100,000 light-years in diameter. You will need dark skies to hunt this one down.
Club Notes Club Observing: The next club meets every 1st and 3rd Saturday 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).
MAC is a proud member of
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Planets Saturn is visible as an evening object during the month and rises during daylight hours throughout the month. With the planet’s ring plane starting to open up, this is not a good time to try and observe the rings in their full glory. It is however a good time to try and observe the smaller satellites and details on the planet’s surface with the rings out of the picture.
Above: The M3 cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is located at a distance of about 33,900 lightyears away from Earth. Mercury, Venus, Mars, Jupiter, Uranus and Neptune are all in the morning sky this month and are not observable this month.
General notes Check out www.heavensabove.com for the latest passes of the International Space Station and satellites, details of Space Shuttle launches and passes and for details of Iridium Flare activity. Clear skies and good hunting!
By Kevin Daly http://members.aol.com/kdaly10475/index.html
Latest Astronomy and Space News Club News Kids Astronomy Quizzes and Games Monthly Sky Guide Internet Highlights
Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Internet Highlights
Stories of the Solar System From our first views of Venus, to rover tracks on Mars, to the outskirts of deep space get an inside peek at the past 50 years of solar system exploration from the men and women who experienced it first-hand. http://youtu.be/dQp_qxw6RTQ
Each month we will try and bring you the best of the web for astronomy online resources such as movies, podcasts and free software. If you have any suggestions for content in these pages please contact us at midlandsastronomy@gmail.com Please click on the links provided to view the material and not the images.
Virtual Star Party - April 28, 2013
NASA 360 - Robots, Rocks, & Rovers
Tonight's Sky: May 2013
Let's Celebrate 23 Years of Hubble
Explore how NASA solves problems - like how to get samples from distant worlds back here to Earth - and spurs innovation through the Centennial Challenges.
Backyard stargazers get a monthly guide to the northern hemisphere's skywatching events with "Tonight's Sky." May is a great month for eclipses, both lunar and solar! And the Eta Aquarid meteors are here to shower the night with lovely sights.
http://youtu.be/DqAdFNoHAKU
http://youtu.be/fHguHHypiwo
http://youtu.be/rnPPfmBspaU
ScienceCasts: A Whiff of Dark Matter on the ISS
Podcast: Earthquakes We always say that the Universe is trying to kill you, but actually, the Earth isn't so fond of you either. Certain parts of planet Earth are prone to earthquakes, where the planet's shifting plates can cause the ground to shake violently. We've had a few devastating earthquakes in recent years, but do they also happen on other worlds? http://www.astronomycast.com/
Podcast: The Jodcast
http://youtu.be/54AxeJFlVgI
A podcast about astronomy including the latest news, what you can see in the night sky, interviews with astronomers and more. It is created by astronomers from The University of Manchester's Jodrell Bank for anyone interested in things out of this world.
http://youtu.be/M1p32TDiydE
Useful free astronomy resources Midlands Astronomy Club have created a Google+ page so that our members and non-members alike can: • Keep up-to-date on future outreach events. • Be informed of upcoming lectures. • Have online access to the latest astronomy news as it happens. • See photos of all club events and activities.
IFAS Website
http://www.irishastronomy.org
Stellarium
http://www.stellarium.org
Virtual Moon Atlas
http://www.astrosurf.com/avl/UK_index.html
Celestia
http://www.shatters.net/celestia/index.html
Sky Maps
http://skymaps.com/index.html
Heavens-Above
http://www.heavens-above.com/
http://www.jodcast.net/archive/
www.midlandsastronomy.com Page - 13
www.midlandsastronomy.com Page - 14
Midlands Astronomy Club Magazine
Midlands Astronomy Club Magazine
Internet Highlights
Stories of the Solar System From our first views of Venus, to rover tracks on Mars, to the outskirts of deep space get an inside peek at the past 50 years of solar system exploration from the men and women who experienced it first-hand. http://youtu.be/dQp_qxw6RTQ
Each month we will try and bring you the best of the web for astronomy online resources such as movies, podcasts and free software. If you have any suggestions for content in these pages please contact us at midlandsastronomy@gmail.com Please click on the links provided to view the material and not the images.
Virtual Star Party - April 28, 2013
NASA 360 - Robots, Rocks, & Rovers
Tonight's Sky: May 2013
Let's Celebrate 23 Years of Hubble
Explore how NASA solves problems - like how to get samples from distant worlds back here to Earth - and spurs innovation through the Centennial Challenges.
Backyard stargazers get a monthly guide to the northern hemisphere's skywatching events with "Tonight's Sky." May is a great month for eclipses, both lunar and solar! And the Eta Aquarid meteors are here to shower the night with lovely sights.
http://youtu.be/DqAdFNoHAKU
http://youtu.be/fHguHHypiwo
http://youtu.be/rnPPfmBspaU
ScienceCasts: A Whiff of Dark Matter on the ISS
Podcast: Earthquakes We always say that the Universe is trying to kill you, but actually, the Earth isn't so fond of you either. Certain parts of planet Earth are prone to earthquakes, where the planet's shifting plates can cause the ground to shake violently. We've had a few devastating earthquakes in recent years, but do they also happen on other worlds? http://www.astronomycast.com/
Podcast: The Jodcast
http://youtu.be/54AxeJFlVgI
A podcast about astronomy including the latest news, what you can see in the night sky, interviews with astronomers and more. It is created by astronomers from The University of Manchester's Jodrell Bank for anyone interested in things out of this world.
http://youtu.be/M1p32TDiydE
Useful free astronomy resources Midlands Astronomy Club have created a Google+ page so that our members and non-members alike can: • Keep up-to-date on future outreach events. • Be informed of upcoming lectures. • Have online access to the latest astronomy news as it happens. • See photos of all club events and activities.
IFAS Website
http://www.irishastronomy.org
Stellarium
http://www.stellarium.org
Virtual Moon Atlas
http://www.astrosurf.com/avl/UK_index.html
Celestia
http://www.shatters.net/celestia/index.html
Sky Maps
http://skymaps.com/index.html
Heavens-Above
http://www.heavens-above.com/
http://www.jodcast.net/archive/
www.midlandsastronomy.com Page - 13
www.midlandsastronomy.com Page - 14