MAC October 2012 Magazine by MAC Realta

Midlands Astronomy Club Magazine

Sky Guide - Beginnerâ&#x20AC;&#x2122;s targets for October For the naked eye in October we have two meteor showers. There is a possible Draconid outburst on the 8th which is predicted to occur around 21:00. However the timing for this event is uncertain and it is best to look as soon as darkness falls. The predicted ZHR is 400, however the presence of a waxing gibbous moon will reduce the number of meteors visible and it is best to keep the moon blocked out by a fence or hedge etc and to look NW where the radiant is visible as soon as darkness falls. The meteors are typically slow and faint and it is unknown how long this event will last for and may only last for a short time. The Orionids peak on the morning of the 22nd with a ZHR of 25. The radiant rises at around 01:00 that morning with a waning crescent moon rising at around 02:00 in Leo causing interference. Telescope Targets The month of October begins with Cassiopeia and Andromeda high overhead in the Northeast. M31 (the Andromeda Galaxy), to locate M31, find the "W" of the Constellation Cassiopeia. The larger part of the base of the "W" points right at the Andromeda Galaxy. Simply follow this line approximately a fist's width and slightly toward the horizon and scan this area with your lowest power eyepiece. You will see a bright blob in the middle with light extending off of both sides. On a very good night from a dark site, Andromeda will fill the field of view of your eyepiece. The Andromeda Galaxy is the most distant object that can be viewed with the naked eye at 2.2 - 2.9 million light years away, which makes this a very easy first galaxy target for your scope. T he A nd r om e d a G a l a x y is considered the Milky Way's twin and is a member of a group of galaxies known as the local group. It's made up of about 300 billion stars and is considerably larger than the Milky Way. M31 is a spiral

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Issue 37 - October, 2012

galaxy, but as we are seeing it edge on no spiral structure can be detected. Within the same low power eyepiece view, you may also detect M32 which is an elliptical galaxy. M32 is a very small smudge just below Andromeda (in the telescope view). It appears to be more of a fuzzy star than a galaxy through most beginners instruments but it's still another distant galaxy composed of millions of s ta r s . M 3 2 is loc a te d approximately 20,000 light-years South of Andromeda. It is a dwarf elliptical galaxy. Also within the same low power field of view as Andromeda is the elusive M110, another galaxy. It's located on the opposite side of Andromeda about the same distance as M32. It will take dark skies to see this one. It's a faint oval smudge even in my 8" scope. This is a dwarf elliptical galaxy containing just a few million stars. Both of these galaxies are orbiting M31. Moving over to Cassiopeia, M103 is our next target. To locate M103 find the star that makes up the bottom of the smaller part of the "W" of Cassiopeia (Ruchbah), M103 is located right next to this star in a straight line from it toward the star that makes the end of the "W" (Epsilon Cygni). M103 is a very loose open cluster of about 60 stars. Next, we'll use Ruchbah again, but with the other side of the "W" to find NGC's 869 and 884 (commonly referred to as the Perseus DoubleCluster). Follow this line down approximately a fist's width, and using your lowest power eyepiece, you will be treated to one of the most beautiful sights in the heavens. NGC 869 and 884 are a pair of Open Clusters each containing approximately 100 stars. It is located a a very rich area of stars which only adds to the beauty of this target. The sight is indeed a memorable one, and one I'm sure you'll return to often to show your friends. Use your lowest power to get the best view of this pair in your eyepiece.

Moving back up through Cassiopeia, our next target will be the open cluster M52. Using the large part of the "W", (alpha and beta Cygni) as our pointer, follow this line straight up about the same distance, and M52 will be in you field of view. M52 is an open cluster containing about 200 members.

The Planets Mercury, Mars and Saturn are not visible this month. Jupiter, Uranus and Neptune are evening objects this month while Venus can be found in the morning

By Kevin Daly http://members.aol.com/kdaly10475/index.html

Club Notes Club Observing: Perseids StarBQ 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).

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Monthly Sky Guide Internet Highlights

Midlands Astronomy Club Magazine

A Black Hole in Orion? ......................................................... 7 Silver in Space: Metal found to form in distinct star explosions........................................................................... 8 Planets can possibly form in the galactic centre ..................... 8 The Flying Unicorn Cluster ................................................... 9

Front cover image: South of Antares, in the tail of the nebularich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, radiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow, dominated by the red emission of hydrogen. At an estimated distance of 6,000 light-years, the region shown is about 250 light-years across, spanning an area equivalent to four full moons on the sky. The nebula is also catalogued as Gum 56 for Australian astronomer Colin Stanley Gum, but seafood-loving astronomers might know this cosmic cloud as The Prawn Nebula.

Credit & Copyright: Marco Lorenzi

NGC 2736: Part of a celestial witch’s broom? ........................ 9

Kids Section Kids Korner ....................................................................... 10

Quizzes and Games Exercise your brain ............................................................ 11

Monthly Sky Guide Beginners sky guide for this month .................................... 12

3. What is a solar eclipse? when the sun explodes when the moon moves between the earth and the sun when the sun emits solar flares when the sun moves between the earth and the moon

galaxy constellation nebula aurora borealis

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8. Why do planets shine? because we are not in a black hole planets have their own source of energy they reflect the sun our galaxy glows

wanderer large meteor fuzzy snowball atlas 10.What is a 'nebula'?

Special content only available with the online version of the magazine ................................................................ 13 Confused???

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million miles billion miles light years trillion miles

4. A group of stars named by ancient people because of heroes or 9. The word 'planet' comes animals they reminded from a Greek word meaning…? them of is called a ...

Check your answers on this page.

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93 93 93 93

a fast moving comet a cloud of gas and dust a new star the shadow of distant stars

5 5

4 8 7

Check your answers

through the different layers of air in our atmosphere, are bent, making them appear to twinkle!

Jupiter explosion spotted by amateur astronomers ................ 6

Answer 1: The correct answer was third rock. That's right folks, we are the third rock from the sun! The order goes: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Planets in our Solar System may have formed in fits and starts ........................................................................... 5

2. About how many stars 6. What is the name of the closest star to our Earth? could you see WITHOUT the use of a telescope or Alpha Centauri binoculars, if you were Andromeda away from the city on a Polaris clear night? Sol 20 2 billion 7. How far away from the 2 million Earth is our sun, 2000 approximately...?

Answer 6: The correct answer was Sol. The name 'Sol' is the word the ancient Romans gave to our sun. It was named after their sun god, Sol.

Amateur Astronomer creates detailed map of Ganymede ....... 5

Answer 2: The correct answer was 2000. With the use of a powerful telescope, you could see millions of stars in just one small part of the sky.

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.

Small Magellanic Cloud reveals a challenge to Big Bang Physics ....................................................................... 4

Answer 7: The correct answer was 93 million miles. If we could travel at the speed of 25,000 miles per hour, it would take more than 5 months to reach the sun. But I don't think we would want to get that close!

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..

Answer 3: A lunar eclipse is when the Earth moves between the sun and the moon. The Earth then casts its shadow upon the moon.

New Comet discovered may become “One of the brightest in history” ............................................................. 4

Answer 8: Planets are like huge mirrors in the sky. The sun shines light onto the planets, and that light is reflected back out into space, making them visible to us.

A cluster with a secret ......................................................... 3

Answer 9: The correct answer was wanderer. Atlas, according to a Greek myth, was a giant whose shoulders supported the heavens. A comet is a fuzzy snowball. Planets move in a path around the sun. Each planet has a different and unique orbiting path around the sun.

Streams of water once flowed on Mars; NASA says photos prove it .................................................................... 3

SUDOKU

1. Compared to the other 5. Why do stars appear to twinkle when we look at planets in our solar them? system, where is the Earth? The _____ from stars are different colours the sun? the earth's atmospheric closest layers bend their light middle rock rays stars fluctuate their sizes furthest only little stars twinkle third rock

Answer 4: The correct answer was constellation. Two constellations named after heroes in their myths include, Hercules and Orion. Some constellations named for what they looked like include Lyra (a harp), Corona Borealis a (crown), Leo ( a lion), Lupus (a wolf), and Ursa Major (a bear). One of the most famous conste llations in the Nor ther n Hemisphere is Ursa Major, the Big Bear. This is where you will find the Big Dipper, which looked to the ancient people like, what else, a huge dipper in the sky!

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Exercise your brain

Answer 10: The correct answer was a cloud of gas and dust. Nebula comes from the Latin word meaning cloud.

contents

Answer 5: If you were in space, the stars would usually shine with a steady light. But their light rays, when passing

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 What are Constellations anyway? A constellation is group of stars like a dot-to-dot puzzle. If you join the dots--stars, that is--and use lots of imagination, the picture would look like an object, animal, or person. For example, Orion is a group of stars that the Greeks thought looked like a giant hunter with a sword attached to his belt.

shapes and positions of the constellations in Earth's sky change very, very slowly. During one human lifetime, they change hardly at all. So, since humans first noticed the night sky they have navigated by the stars. Sailors have steered their ships by the stars. Even the Apollo astronauts going to the Moon had to know how to Other than making a pattern in navigate by the stars in case their Earth's sky, these stars may not be navigation instruments failed. related at all. For example, Alnitak, the star at the left side of Orion's belt, is 817 light years away. (A light year is the distance light travels in We see different views of the one Earth year, almost 6 trillion Universe from where we live as miles!) Alnilam, the star in the Earth makes its yearly trip around middle of the belt, is 1340 light the solar system. That is why years away. And Mintaka at the right we have a different Star Finder side of the belt is 916 light years for each month, as different away. Yet they all appear from Earth constellations come into view. Also, as Earth rotates on its axis toward to have the same brightness. the east throughout the hours of Even the closest star is almost unimaginably far away. Because they are so far away, the

Finding the Constellations

the night, the whole sky seems to shift toward the west. The Star Finder charts are for a latitude of 34º N, which is about as far north of the equator as Los Angeles, California. (Charts are from The Griffith Observer magazine.) The farther north you are, the more the constellations will be shifted south from the Star Finder charts. The Star Finder charts show the sky at about 10 PM for the first of the month, 9 PM for the middle of the month, and 8 PM for the last of the month. These are local standard times. For months with Daylight Savings Time, star chart times are an hour later. The star charts are maps of the sky overhead. So, to get the directions lined up, hold the map over your head and look up at it, and turn it so the northern horizon side is facing north. If you live where big city lights drown out the beauty of the stars, you may see only a few of the brightest stars and planets. How sad! But see if you can find at least one or two constellations on a clear, Moonless night.

Right: An artist's impression of the TacSat-2 satellite in space.

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What Else are Constellations Good For? Star patterns are also very helpful for navigating a spacecraft. Most spacecraft have steered by the stars--or at least checked the stars once in a while to make sure the spacecraft was still on course and pointed in the right direction. Space Technology 6 is a mission to test a new, very small and energy-efficient kind of reference system. This new system is called an Inertial (in-ER-shul) Stellar Compass, or ISC. The ISC is made up of a star tracker and a gyroscope. Working together, they keep the spacecraft on course. The star tracker, like a camera, takes a picture of the star patterns in its view and compares the picture with its built-in star maps. This is how it can tell the spacecraft exactly which way it is pointed. In between pictures from the star tracker, the gyroscope tells the spacecraft how it is pointed. Together the star tracker and gyroscope keep the spacecraft stable and oriented in the right direction in space (for example, not flying "upside-down" or sideways). But the gyroscope can hold stable for only a short time. To keep the gyroscope perfectly accurate, information from the star tracker is sent to the gyroscope every few seconds. The thing that is new and different with the Space Technology 6 ISC is that the two devices are combined into one tiny, light-weight system that needs little power to run. The ISC was tested on the U.S. Air Force TacSat-2 microsatellite, and it worked just fine. Now the ISC technology can be used on future spacecraft sent on missions of discovery.

Streams of water once flowed on Mars; NASA says photos prove it NASA's Curiosity rover has found definitive proof that water once ran across the surface of Mars, the agency announced today. NASA scientists say new photos from the rover show rocks that were smoothed and rounded by water. The rocks are in a large canyon and nearby channels that were cut by flowing water, making up an alluvial fan. "You had water transporting these gravels to the downslope of the fan," NASA researchers say. The gravel then formed into a conglomerate rock, which was in turn likely covered before being exposed again. The agency's scientists presented their findings of the former streambed on Mars at a news conference today. "A River Ran Through It," Curiosity's operators recently tweeted. "I found evidence of an ancient streambed on Mars, similar to some on Earth." "From the size of gravels it carried, we can interpret the water was moving about 3 feet per second," s a id C ur ios ity s c ie nc e c oinvestigator William Dietrich, "with

a depth somewhere between ankle and hip deep." The rocks have not undergone scientific analysis. But the NASA team says that taken with geographic data from Mars orbiters, the photographs tell a story all their own. The images show rocks with round, smooth surfaces; many of them have been broken down into sizes smaller than one inch in diameter. "The shapes tell you they were transported and the sizes tell you they couldn't be transported by wind," co-investigator Rebecca Willia ms s aid . "T he y wer e transported by water flow."

A cluster with a secret A recent survey of the stars in globular cluster M4 has uncovered one sun with more lithium than expected. A new image from the European Southern Observatory's (ESO) La Silla Observatory in Chile shows the spectacular globular star cluster Messier 4. This ball of tens of thousands of ancient stars is one of the closest and most studied of the globular clusters, and recent work has revealed that one of its stars has strange and unexpected properties, apparently possessing the secret of eternal youth. The Milky Way Galaxy is orbited by more than 150 globular star clusters that date back to the distant past of the universe. One of the closest to the Earth is the cluster M4 (also known as NGC 6121) in the constellation of Scorpius the Scorpion. This bright

object can be easily seen in binoculars, close to the bright red star Antares, and a small amateur telescope can show some of its constituent stars. This new image of the cluster from the Wide Field Imager (WFI) on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory reveals many more of the cluster’s tens of thousands of stars and shows the cluster against the rich background of the Milky Way. Astronomers have also studied many of the stars in the cluster individually using instruments on ESO’s Very Large Telescope. By splitting the light from the stars up into its component colours they can work out their chemical composition and ages. New results for the stars in M4 have been surprising. The stars in

"There is e a r l i e r evidence for the presence of water on Mars," the agency said in a press release, "but this evidence — images of r o c k s containing ancient streambed gravels — is the first of its kind." NASA's team has named the rock outcrop that reveals the former streambed "Hottah," after Canada's Hottah Lake. Scientists have not yet estimated the age of the rocks, which may have been buried beneath the surface. Their age could be several billion years. The next step will be to find a good spot to drill into the rock, NASA says. And they'll be looking for possible carbon deposits to determine whether the water on Mars once supported life. globular clusters are old and hence not expected to be rich in the heavier chemical elements. But in a recent survey, astronomers found that one the M4 stars has much more of the rare light element lithium than expected. The source of this lithium is mysterious. Normally, this element is g r a d u a l l y destroyed over the billions of years of a star’s life, but this one star among thousands seems to have the secret of eternal youth. It has either somehow managed to retain its original lithium, or it has found a way to enrich itself with freshly made lithium. www.astronomy.com

Above: NASA says that water shaped the rocks on the left, in a photograph taken by the Mars rover Curiosity. For comparison, the agency released an image of rocks from the Earth (right). The photographs released Thursday are among more than 13,000 raw images Curiosity has captured. The rover took the photos during its mission to Mars' Gale Crater. The rocks in question lie between the crater's north rim and Mount Sharp, a mountain inside the crater. www.npr.org

This image shows the globular star cluster Messier 4. This great ball of ancient stars is one of the closest of such stellar systems to the Earth. New observations have revealed that one star (marked on this picture) has much more lithium than the other stars in the cluster. The source of this lithium is mysterious. Normally this element is gradually destroyed over the billions of years of a star's life.

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Midlands Astronomy Club Magazine

The Flying Unicorn Cluster

New Comet discovered may become “One of the brightest in history”

The constellation Aquila, the Eagle, has few sights for a small telescope. Which is surprising, since the constellation lies along the northern Milky Way between the rich star clouds of Cygnus and the galactic opulence of Sagittarius. But a handful of clusters and nebulae fleck patches of stars in Aquila that stand out from the dark clouds of the Great Rift of the Milky Way. Perhaps the finest open cluster in the constellation is NGC 6709. It’s a sprawling irregular group of stars which, to some stargazers, looks like a sparkling unicorn.

If astronomers' early predictions hold true, the holidays next year may hold a glowing gift for stargazers—a super bright comet, just discovered streaking near Saturn. Even with powerful telescopes, comet 2012 S1 (ISON) is now just a faint glow in the constellation Cancer. But the ball of ice and rocks might become visible to the naked eye for a few months in late 2013 and early 2014—perhaps outshining the moon, astronomers say. The comet is already remarkably bright, given how far it is from the sun. What's more it seems to be following the path of the Great Comet of 1680, considered one of the most spectacular ever seen. "If it lives up to expectations, this comet may be one of the brightest in history," said Samra, of the H.R. M a cM illa n Sp a c e C e ntr e in Vancouver, Canada. So what makes a comet a showstopper? A lot depends on how much gas and dust is blasted off the central core of ice and rocks. The bigger the resulting cloud and tail,

the more reflective the body. Because 2012 S1 appears to be fairly large and will fly very close to the sun it’s calculated that the comet may shine brighter, though not bigger, than the full moon in the evening sky. Refugee From the Edge of the Solar System? First spotted late last week by Russian astronomers Artyom Novichonok and Vitali Nevski of the International Scientific Optical Network (ISON), comet 2012 S1 was confirmed by the International Astronomical Union on Monday. But while we know what 2012 S1 is, it's still unclear where it came from. Its orbit suggests the comet may be a runaway from the Oort cloud, where billions of comets orbit on the edge of the solar system. "For astronomers, these distant origins are exciting because it allows us to study one of the

Small Magellanic Cloud reveals a challenge to Big Bang Physics Stars in the Milky Way have about four times less lithium on the surface than expected by Big Bang predictions. Some scientists suggest that stellar activity might destroy lithium, or the element might sink from the surface through lighter hydrogen, but the remarkably consistent ratio from star to star is a challenge to those explanations. Observations of gas in the Small Magellanic Cloud revealed the amount of lithium that predictions say would have been produced at the Big Bang, but leave no room for subsequent production of the element. One explanation could be a novel kind of physics operating at the Big Bang that left less lithium than the Standard Model predicts. J. Christopher Howk, Nicolas Lehner and Grant Mathews of the Centre for Astrophysics at the University of Notre Dame published a paper this week in the journal Nature titled

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"Observation of interstellar lithium in the low-metallicity Small Magellanic Cloud." The astrophysicists have explored a discrepancy between the amount of lithium predicted by the standard models of elemental production during the Big Bang

Above: Sky-watchers in Australia ogle comet Lovejoy late last year. oldest objects in the solar system still in its original, pristine condition."

star's intense heat and gravity could cause the ice and rubble to break apart, scotching the sky show.

New Comet Bound for Glory? Right now, 2012 S1 appears to be about 990 million kilometres from Earth, between the orbits of Saturn and Jupiter. Current orbital predictions indicate the comet will look brightest to us in the weeks just after its closest approach to the sun, on November 28, 2013, if it survives the experience.

"While some predictions suggest it may become as bright as the full moon, and even visible during the day, one should be cautious when predicting how exciting a comet may get. Some comets have been notorious for creating a buzz but failing to put on a dazzling display," he said. "Only time will tell." www.nationalgeographic.com

As the comet comes within about 2 million kilometres of the sun, the and the amount of lithium observed in the gas of the Small Magellanic Cloud, a galaxy near to our own. "The paper involves measuring the amount of lithium in the interstellar gas of a nearby galaxy, but it may have implications for fundamental physics, in that it could imply the presence of dark matter particles in the early universe that decay or annihilate one another," Howk says. "This may be a probe of physics in the early universe that gives us a handle on new physics we don't have another way to get a handle on right now." Using observations from European Southern Observatory's Very Large Telescope (VLT) in Chile, the team measured the amount of lithium in the interstellar gas of the Small Magellanic Cloud, which has far fe w e r s tar -p rod uc e d he a vy

elements than the Milky Way. In addition to the production of elements by fusion in the core of stars, scientists believe conditions immediately after the Big Bang led to the formation of some elements, including a small amount of lithium. The team will conduct three nights of observations on the VLT in November. They will look for the lithium isotope 7Li in the Large Magellanic Cloud and 6Li in both the Large Magellanic Cloud and the Small Magellanic Cloud. The standard model predicts that no 6Li was created at the Big Bang. www.dailygalaxy.com

NGC 6709 lies off the northern wing of Aquila near the intersection with the constellations Hercules and Ophiuchus. Look for the group about 5º SW of ζ (zeta) Aquilae. It forms a narrow right triangle with zeta and ε (epsilon) Aquilae (see map). This 7th-magnitude cluster is easily visible in 7×50 binoculars, and higher-magnification binoculars begin to resolve the group. In a 3inch or larger telescope the cluster bursts open like a small backyard firework, with chains and loops of stars spread over a quarter degree of sky. The cluster reveals detail at all magnifications. At 25-40x, you

can take in the overall shape of the group and enjoy the dense tapestry of background stars. Medium and high magnifications reveal, to the patient observer, numerous double stars among the cluster’s loops and chains. At low power, look for two irregular groups to the east and west of the cluster’s sparse centre. The western group looks like an irregular “V” while the eastern appears as an inverted “J” with fainter loops to the west. Let your eye and imagination relax, and you may see the western “V” as the front leg, head, and horn of a unicorn, with the rounded body

Above: Red circle at right shows the position of NGC 6709 in the constellation Aquila . and rear leg to the east. Look carefully at the image at the top of the page. The unicorn is facing right…

A new view of the Pencil Nebula shows large, wispy filamentary the gas was heated to millions of structures, smaller bright knots of gas, and patches of diffuse degrees, but it then subsequently cooled down and is still giving off gas. The Vela supernova remnant is an expanding shell of gas that originated from the supernova explosion. Initially, the shock wave was moving at millions of kilometres per hour, but as it expanded through space, it ploughed through the gas between the stars, which has slowed it considerably and created strangely shaped folds of nebulosity. The Pencil Nebula is the brightest part This new image from the Wide Field of this huge shell. Imager shows the Pencil Nebula against a rich starry background. This new image shows large, This oddly shaped cloud, which is wispy filamentary structures, also known as NGC 2736, is a small smaller bright knots of gas, and part of a supernova remnant in the patches of diffuse gas. The southern constellation of Vela the nebula’s luminous appearance Sails. The brightest part resembles comes from dense gas regions that a pencil but the whole structure have been struck by the supernova looks rather more like a traditional shock wave. As the shock wave travels through space, it rams into witch’s broom. the interstellar material. At first,

www.oneminuteastronomer.com

NGC 6709 is about 3,900 light years away and spans about 17 light years. Spectroscopic studies of the

NGC 2736: Part of a celestial witch’s broom?

The Pencil Nebula is pictured in a new image from the European Southern Observatory’s (ESO) La Silla Observatory in Chile. This peculiar cloud of glowing gas is part of a huge ring of wreckage left over after a supernova explosion that took place about 11,000 years ago. The Wide Field Imager on the MPG/ ESO 2.2-meter telescope produced this detailed view.

group’s 110 members suggest it formed about 300 million years ago.

the faint glow that was captured in the new image. By looking at the different colours of the nebula, astronomers have been able to map the temperature of the gas. Some regions are still so hot that the emission is dominated by ionized oxygen atoms, which glow blue in the picture. Other cooler regions are seen glowing red, due to emissions of hydrogen. The Pencil Nebula measures about 0.75 light-year across and is

moving through the interstellar medium at about 650,000 km/h. Remarkably, even at its distance of approximately 800 light-years from Earth, this means that it will noticeably change its position relative to the background stars within a human lifetime. Even after 11,000 years, the supernova explosion is still changing the face of the night sky. www.astronomy.com

Above: The Pencil Nebula, a strangely shaped leftover from a vast explosion.

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Midlands Astronomy Club Magazine

Silver in Space: Metal found to form in distinct star explosions

Amateur Astronomer creates detailed map of Ganymede

It's long been known that earthly metals like gold and silver were forged in supernova explosions, but the metals' exact origins have been shrouded in mystery. Now a new study has identified the unique nuclear recipe for silver in space.

As frequent “Astrophoto” posts from amateur astronomers and photographers attest as well as the rise of citizen science, the latest technology allows amateurs to make significant contributions to the field of astronomy.

While most common light elements like hydrogen and helium were formed in the big bang, heavier elements like carbon and oxygen are formed within stars through nuclear fusion. Rare heavy metals like silver and gold, however, need the most extreme stellar environments to form—found only during the explosions of massive stars, or supernovae. When these stellar titans die and explode, they spew new materials into space—the origin of most heavy metal elements on Earth, said lead study author Camilla Hansen, an astronomer at Heidelberg University in Germany. To pinpoint just how silver is produced, Hansen's team used computer modelling as well as

Case in point Emmanuel Kardasis of the Hellenic Amateur Astronomy Association who produced the first amateur albedo map of Jupiter’s moon Ganymede. He used an off -the -s he lf te le s c op e , camera and computer equipment and put his observing skills to the test.

observations of more than 70 massive stars. The team analysed light wavelengths to discern the stars' chemical makeups. "The amount of each element is directly connected to how strong the spectral lines are, which relates to how hot the star is," Hansen said. The researchers concluded that Above: Metals like gold and silver spring from supernovae. silver production occurs in less massive stars than those that -mass supernovae and create quite low—as little as a billionth of produce gold—and through an elements up to palladium and the original mass of the star—these entirely different type of nuclear silver," she said, "but not heavier." silver-producing supernovae may be fusion, called the weak r-process. more widespread than their larger, What's more, she said, "it seems gold-producing cousins. The discovery allowed the team to that this weak r-process can be put a limit on the metals certain connected to supernovae of much That cosmic disparity, Hansen said, types of supernovae can create. lower masses than what we may help explain why silver on Earth is so much more abundant thought earlier." "Stars with masses eight to nine than gold. times that of the sun may explode So while the amount of the metal www.nationalgeographic.com at the end of their lives as faint low ejected by a single star may be

Planets can possibly form in the galactic centre

destroyed, the stars that remain in the ring can hold onto their disks. Therefore, they may form planets despite their hostile surroundings.

For proof, scientists point to the recent discovery of a cloud of Murray-Clay and colleague Avi Loeb hydrogen and helium plunging toward the galactic centre, arguing propose a different explanation. N e w - b o r n s t a r s r e t a i n a As the star continues its plunge over that it represents the remains of a planet-forming disk. At first glance, the centre of the Milky Way seems like a very inhospitable place to try to form a planet. Stars crowd each other as they whiz through space like cars on a rush-hour motorway. Supernova explosions blast out shock waves and bathe the region in intense radiation. Powerful gravitational forces from a supermassive black hole twist and warp the fabric of space itself. Yet new research by astronomers at the HarvardSmithsonian Centre for Astrophysics (CfA) shows that planets still can form in this cosmic maelstrom. For proof, they point to the recent discovery of a cloud of hydrogen and helium plunging toward the

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galactic centre. They argue that this cloud represents the shredded remains of a planet-forming disk orbiting an unseen star. “This unfortunate star got tossed toward the central black hole. Now it’s on the ride of its life, and while it will survive the encounter, its protoplanetary disk won’t be so lucky”. Last year, a team of astronomers discovered the cloud in question using the Very Large Telescope in Chile. The group speculated that it formed when gas streaming from two nearby stars collided, like windblown sand gathering into a dune.

surrounding disk of gas and dust for millions of years. If one such star dived toward our galaxy’s central black hole, radiation and gravitational tides would rip apart its disk in a matter of years.

They also identify the likely source of the stray star — a ring of stars known to orbit the galactic centre at a distance of about one-tenth of a light-year. Astronomers have detected dozens of young, bright O -type stars in this ring, which suggests that hundreds of fainter Sun-like stars also exist there. Interactions between the stars could fling one inward along with its accompanying disk. Although this protoplanetary disk is being

“Ganymede has a tiny disk as seen from Earth so was a good test for my techniques,” said Kardasis. “If the same methods were applied to other worlds, perhaps the volcanic moon Io, we could capture s ur fa c e f luc t ua t ions . Professional observatories may create better images but they cannot monitor our rapidly and everchanging Universe.”

the next year, more and more of the disk’s outer material will be torn away, leaving only a dense core. The stripped gas will swirl down into the maw of the black hole. Friction will heat it to high enough temperatures that it will glow in Xrays. “It’s fascinating to think about planets forming so close to a black hole,” said Loeb. “If our civilization inhabited such a planet, we could have tested Einstein’s theory of gravity much better, and we could have harvested clean energy from throwing our waste into the black hole.” www.universetoday.com

Like many amateurs, Kardasis attached a camera to his telescope and recorded a video of

Planets in our Solar System may have formed in fits and starts Conventional thinking says our Solar System all formed at the same time. But new research indicates that a series of shockwaves emitted from our very young Sun may have caused the planets to form at different times over millions of years. “The planets formed in intervals – not altogether, as was previously thought,” said Dr. Tagir Abdylmyanov, Associate Professor from Kazan State Power Engineering University in Russia. Abdylmyanov’s research, which models the movements of particles in fluids and gasses and in the gas cloud from which our Sun accreted,

indicates that the first series of shockwaves during short but very rapid changes in solar activity would have created the protoplanetary rings for Uranus, Neptune, and dwarf planet Pluto first. Jupiter, Saturn, and the asteroid belt would have come next during a series of less powerful shockwaves. Mercury,

Above: The original observations (top) and interpretations (bottom) of the first ever amateur albedo map of Ganymede. Credit: Manos Kardasis. Ganymede. Selecting only the sharpest frames of the video allowed him to obtain a series of images when the atmospheric conditions, known as "seeing", were most favourable. These best images were then stacked and aligned, before being enhanced through photo-editing software. An albedo map details higher areas of reflectivity on an object’s surface recording where material is brighter or darker. Kardasis’ albedo map closely aligns with professional images of Ganymede’s surface, indicating features such as Phrygia Sulcus and the Nicholson region (a low-lying darker area). “Creating images of planets requires a telescope of at least eight inches in diameter. For tiny Venus, Earth, and Mars would have formed last, when the Sun was far calmer. This means that our own planet is one of the youngest in the Solar System. “It is difficult to say exactly how much time would have separated these groups but the protoplanetary rings for Uranus, Neptune and Pluto would have likely formed very close to the Sun’s birth. 3 million years later and we would see the debris ring destined to form Saturn. Half a million years after this we would see something similar but for Jupiter. The asteroid belt would have begun to form about a million years after that, and another half a million years on we would see the very early stages of

discs, such as the moons of Jupiter, bigger is definitely better. You also need a good motor drive on your tripod, a sensitive camera, some freely-available software, and lots of patience!” Kardasis presented his images at the European Planetary Science Congress in Spain. He suggests that future amateur programs could monitor both surface and atmospheric changes on worlds as varied as Uranus , Nep tune a nd Titan, complementing more detailed but far less regular observations made by professionals. Kardasis says, “I hope my work will inspire anyone interested in astronomy to use whatever equipment they have to make useful observations.” www.universetoday.com

Mercury, Venus, Earth and Mars.” The shockwaves emitted from the new-born Sun would have rippled out material at different times, creating a series of debris rings around the Sun from which the planets formed. Abdylmayanov hopes that this research will help us understand the development of planets around dis ta nt sta rs . “Stud ying the brightness of stars that are in the process of forming could give indications as to the intensity of stellar shockwaves. In this way we may be able to predict the location of planets around far-flung stars millions of years before they have formed.” www.universetoday.com

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Midlands Astronomy Club Magazine

Jupiter explosion spotted by amateur astronomers

A Black Hole in Orion? The Orion Nebula Cluster might be home to a black hole more than 100 times the mass of the Sun, according to a recent simulation. At 1,300 light-years away, that would make it the closest known black hole to Earth.

Early this month amateur astronomers spotted a bright light squiggling across the upper cloud deck of Jupiter. Both assumed they'd witnessed a large meteor or comet impact, and so far, professional astronomers seem to agree. NASA's Amy Simon Miller, though, cautioned that, "at this point, we can only confirm based on the fact that there were two independent reports." Official observations will have to wait. Such a strike would be the fourth impact seen on Jupiter in just the last three years. And the fact that the explosion was visible via backyard telescopes more than 730 million kilometres away—indicates it was probably a significant event. "Although we don't yet know the size or exact nature of the impactor, based on the flash brightness we expect it is slightly bigger and energetic than the one seen in 2010, which was estimated to be on the order of 10 meters in size," said Miller, chief of the planetary systems laboratory at Goddard Spaceflight Centre in Maryland. "By contrast, the impactor in 2009 was likely 200 to 500 meters." Leaving a Mark on Jupiter? Amateur astronomer Dan Peterson,

in Racine, Wisconsin, watched the Jupiter impact live while peering through a 12-inch telescope. Later, his counterpart to the south— George Hall of Dallas, Texas— realized he'd accidentally caught the flash on video, thanks to a webcam-telescope link. "My best guess is that it was a small undetected comet that is now history," wrote Peterson on a telescope message board post titled "I observed an explosion on Jupiter this morning!" "Hopefully," he added, "it will sign its name on Jupiter's cloud tops." Searching for that signature—dark markings on Jupiter's cloud tops— is exactly what astronomers should do next, NASA's Miller said. "An impact superheats the immediate atmosphere and will essentially produce soot," she said. Only if such stains are spotted will heavy-duty telescopes be enlisted to confirm the Jupiter blast, she said. "Professional telescopes and

Most of space is empty. Even when galaxies collide, individual stars are far more likely to exchange passing glances than meet head-on.

H u b b l e a r e t y p ic a l l y ve r y oversubscribed and won't be called into action unless a debris field is confirmed first by amateurs." Jupiter Impacts "Probably Quite Frequent" Before the recent rash of Jovian collisions, it was thought that Jupiter impacts were rare cosmic events—with the 1994 death of comet Shoemaker-Levy 9 a spectacular exception. That impactor consisted of at least 21 fragments, some as wide as 2 kilometres, according to NASA. Now astronomers have begun to think the impacts are in fact fairly common. On Jupiter "very small e ve nts a r e p roba b ly quite frequent," Miller said, though many would occur on the half of the planet we can't see. "In fact, they probably happen up to once a week, but some would be too small to even make a flash." With more tech-savvy amateurs like Peterson and Hall monitoring Jupiter on a regular basis, she said, scientists hope to get a better grip on the number of meteors floating in Jupiter's vicinity—one grainy video at a time. "The impacts in 2009 and then 2010 showed that there were very many smaller objects out near Jupiter with the potential to impact," Miller said.

Above: This graphic of Jupiter by UK astronomer Pete Lawrence shows the location of the Jupiter impact region from Sept. 12, 2012, as seen through an inverting astronomical telescope. The impact site is located at longitude system II 335, latitude +12.

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"At that point we expected that many more sightings would occur," she added, "so this new one confirms our hypothesis." www.nationalgeographic.com

Above: Amateur astronomer George Hall captured this image of an apparent impact on Jupiter while recording video telescope observations of the planet on Sept. 10, 2012, from Dallas. The bright flash captured on amateur video lasted roughly two seconds.

Some interesting facts about Jupiter Jupiter's famous Red Spot is in fact a storm the size of Earth that has raged for hundreds of years. Jupiter has a thin set of rings, hardly visible with telescopes from Earth. Jupiter is the vacuum cleaner of the Solar System. It sucks in comets, asteroids and meteorites which could be on a collision course for Earth. Jupiter takes only 9 hours and 55 minutes to spin on its axis. This means a day on Jupiter is less than 10 hours long. If we were able to stand on the surface of Jupiter, we would weigh three times as much as we would weigh on Earth. The mass of Jupiter is 318 greater than the mass of Earth. Jupiter's moon, Ganymede, is the biggest moon in the Solar System. If we were able to see Jupiter's radiation belt from Earth, Jupiter would appear as big as the Sun.

But space is a little less empty in the Orion Nebula Cluster, one of the many star clusters hanging from the mythic warrior’s belt. In the cluster’s early years, stars might have been packed so tightly that physical run-ins would be unavoidable. According to a new simulation conducted by Ladislav Šubr (Charles University, Czech Republic) and his colleagues in the September 20th Astrophysical Journal, these multiple mergers could have created a massive black hole that dominates the core of Orion Nebula Cluster. The odds that a star will run directly into another star increase with the star’s mass. When two normal stars do collide, the result is a single, more massive star. Because this larger star is more likely to have yet another star run into it (because it’s bigger than it was before), collisions can lead to a runaway effect, as this star

continues to cannibalism.

grow

via

stellar

The computer simulation performed by Šubr and his colleagues shows that this runaway string of collisions could grow a central black hole up to 150 times more massive than the Sun. The idea of runaway black hole growth in stellar clusters isn’t new, but previous studies have focused on high-mass star clusters, ideal breeding grounds for black holes thousands of times the mass of the Sun. The new simulation is the first to show that even low-mass star clusters could grow their own, more modest black holes, says Jan Pflamm-Altenburg (Bonn Astronomy Institute), who was not involved in this study.

The team’s simulation is simple in principle — the computer code calculates primarily the gravitational interactions between thousands of stars. If two stars get too close together, the code merges them into one. Stars can also escape the cluster if they gain enough speed t h r o u g h interactions with other stars. Stellar mergers happen often in the simulated cluster’s early years, when the newborn stars huddle closer t o g e t h e r . Multiple runs of the simulation make clear that, assuming the Orion Nebula Cluster was more compact in its past, a black hole with a mass of at least 100 i s Above: A 150-solar-mass black hole could explain the high S u n s inevitable. speeds of the Trapezium stars, the four hottest and most massive stars in the Orion Nebula Cluster.

Above: The Orion Nebula star cluster is tucked in the center of the photogenic Orion Nebula. The cluster core is dominated by the four Trapezium stars. If it exists, that black hole probably isn’t growing much toda y. Astronomers think that after only a few hundred thousand years, the Orion cluster’s hottest, most massive stars began emitting intense radiation that drove away the star-forming gas enshrouding the young cluster. The cluster swells in size as the gas escapes because there is less mass holding the cluster together, and some weakly bound stars escape. The simulation mimics this expulsion, producing a cluster that loses about two-thirds of its mass and expands to five times its initial size. In the expanded cluster stars collide less frequently, and the runaway growth of the black hole slows down. In the simulation, many of the heaviest stars either merge or escape, which might explain why only 10 OB stars are currently observed in the cluster, much fewer than the 40 OB stars expected. Even if a black hole is inevitable in the Orion cluster, the trick will be to observe it. In general, black holes become visible when they feed on gas from their surroundings, because the gas

heats up and emits light. But there’s not enough gas in the Orion Nebula Cluster to feed the black hole in sufficient quantities. And even though the simulation indicates that the black hole probably forms a binary system with a star, the two will likely be too far apart for the black hole to feed off its companion. A black hole could also be observed indirectly, by measuring its effect on the stars whirling in the cluster core. Šubr and his colleagues suggest that a 150-solar-mass black hole could explain the high speeds of the Trapezium stars, which lie at the Orion Nebula’s heart. But thorough observations of the cluster’s innermost 0.2 light-year are still needed to reveal whether the black hole exists, the authors conclude. The Orion Nebula Cluster is one of the closest young star clusters, about 1300 light-years away, making it easier to study than the massive clusters, which lie at greater distances. “If a black hole really exists in the ONC, then it might be the closest black hole known to Earth,” Pflamm-Altenburg adds. www.skyandtelescope.com

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