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Journal of the Northern Sydney Astronomical Society Inc. Volume 21 Number 4 October 2010

In this issue s you are certainly aware of, the contributions as you wish. Page 1: Editorial Geoff Welch Literary Competition Your articles do not have to be byzantine. A President’s message is now back on track. You will find In fact they should be an easy and Page 2: Calendar/Communications enclosed a brief background story on this interesting read for all members so, fire Hubble images at Imax competition as well as the amended rules. up your computer and send them to Page 3: Impact on Jupiter [email protected], Richest The competition runs from October to July I’m eagerly waiting for them. Page 4: Synchronous rotation of the following , which means that it Observing from Sydney is now open but you still have 9 months to Cheerio, Page 5: Water vapour on carbon send your entry for this year. Jean-Luc Gaubicher Page 6: Life in the Blue Mountains Page 7: St Ives North PS Star Party Everybody can enter and, for more chance Page 8: Sausage sizzle to win a prize, you can send as many Secret message President’s Message his issue of Reflections should be So what have we done during the year? depend on new members with interest in Treaching you early October, so it’s I’m pleased that we have been able to observing. now the end of the Society’s year. maintain a very high level of presenters from the professional astrophysical field, After having been very static for a couple The NSAS Annual General Meeting will and in particular, we were fortunate to get of , the NSAS website has been be on Tuesday the 19th of October at St. a strong group from Macquarie University completely rebuilt, and quite recently, Ignatius, and as Presidents usually do, I and CSIRO, as support from the traditional has been made much more dynamic, with urge you to attend and make your thoughts Universities has dried up this year. On current astronomical news on the front about the Society known and, if you would the basis of a conscious decision by page. More needs to be done, and will be, like to participate more than you did this last the Committee to back off on outreach as our volunteers have time. year, consider nominating for a position on activities, we have had a more modest year the Committee, or at least volunteering for in this respect, with support of Macquarie Finally, one of the Committee’s one of the many roles in the Society that go Open Night, St. Ignatius Science Week achievements of the current year has been to make up the “little jobs” that make the (washed out) and some schools, including the successful resolution to amend the difference in how the Society delivers to St. Ives North Public. Thanks to all Constitution of the Society to make more its membership. the volunteers who have supported the clear the obligation of members to pay outreach this year. their dues within a reasonable time, and to The Society continues to attract new allow the Society to cancel the membership members but in much lower numbers than The various core groups and streams have of non-financial members, which was not during the IYA09 and, in fact, we have continued with varying interest this year. possible under the Model Constitution had more or less a balance of member The Theory Group continues to work its under which we operate. numbers since the start of the year, with way through “Understanding the Universe” some leaving and some joining, leaving to great satisfaction of the participants. I’ve enjoyed being your President for the us with about 60 members. One of the Observing has had a marginal year, with current year, and whether I continue in that things that we really need to consider is particularly bad weather at Observing dates, role or another depends on whether I can whether this is an adequate membership to but there have been a couple of successful convince some of you to take an active provide the activities and services that the sausage sizzles at North Turramurra, and role in the management Society presently supports. I believe most one good night at Mt White earlier this of the Society for the of the current Committee has come to the year. We’re thinking of another Mt White next year. See you at conclusion that we need to increase our night before the end of the year. The New the AGM. membership to get an adequate number of Astronomers Group has been quite active volunteers to carry out the current activities at times during the year, even though there Best Regards, of the Society, and we will have to come have only been a limited number of new up with some effective recruitment in the members with scopes. As of late, it appears Bob Fuller future. to be tiring, and the future of the NAG may Calendar General Meetings: October 19th Annual General Meeting Guest Speaker: TBA November 16th Guest Speaker: TBA December 21st Christmas Party

NAG Meetings: October 26th November 23rd

Theory Group Meetings: October 12th November 9th December 14th

Observation Nights: October 1st / October 15th November 5th / November 12th December 3rd / December 10th

Deadline: Please send your contributions to the April issue of Reflections in time to reach the editor before December 15th to [email protected]

Hubble Images at Imax was privileged to be able to attend the It was good to see the session before them. I expected school children chatter I preview for teachers of the stunning theirs, as they came pouring in, almost all but the talk was of what had impressed Hubble images, back in August. were school children, What a worthwhile them most, a varied lot of opinions, and Even more interesting was my inclusion audience! all about their admiration of what they had in the attendance of my granddaughter’s I was seated amongst the children, They seen. class of 11-year old students of the same were attentive and obviously impressed 3D performance, the following week. by the overwhelming difficulties that were I certainly found it worthwhile seeing these successfully overcome. Hubble images a second time and was The class travelled down from Morpeth, inspired by the children’s deep appreciation near Maitland, took in the Power House But what surprised me the most, was of their experience. Museum’s Space Display and came on to the discussion on the bus home when I Lydia Bell Imax at Darling Harbour. travelled back up with

Pictures by the author

Shop 3075, Westfield Shopping Centre Cnr Florence and Hunter Streets Hornsby NSW 2077 Australia Phone: 02 9257 0092 www.australiangeographic.com.au Impact on Jupiter... Again! am a frequent visitor to the forums of Bird is actually Anthony Wesley, an I IceInSpace as it is a great place to catch amateur astronomer in Broken Hill who up with what is happening with amateur became famous in July 2009 by being the astronomy in Australia. first to detect the impact of an asteroid on While I was browsing through the various Jupiter which left clearly visible marks on forums, I happened across one post which the planet.. had just been added. Well Anthony Wesley It was dated 3rd June 2010 at 9:20 pm and has done it again and was titled “Jupiter Impact, June 3 2010“ the post above was how You can probably see why this article he revealed that just caught my eye. I looked at the post and this 11 months later he has is what it said: witnessed and recorded a 2nd impact on Jupiter..... Jupiter Impact, June 3 2010. this time an impact which Morning all :-) has left no marks. This is not a hoax, at approximately Though there are no visible 20:30utc this morning I recorded a large signs of the impact, the fireball on Jupiter, it lasted a couple of video footage and images seconds and was very bright. of the event are amazing. I have it recorded on video :-) One person reading the I’m at Trevors place at the moment, using posts by “Bird” suggested his internet, I’ll put together a short video that NASA should put later. him on their payroll if he This was a large fireball, but it doesn’t keeps on discovering new seem to have left any mark, probably all events. gone in the upper atmosphere before it Roy Jordan reached the clouds. How exciting! Cheers, Bird

Richest Planetary System Discovered stronomers using ESO’s world- long study of the Sun-like star HD 10180, –Sun distance from their central star. Aleading HARPS instrument have located 127 light-years away in the southern “We also have good reasons to believe that discovered a planetary system of two other planets are present,” says Lovis. containing at least five planets, . HARPS One would be a -like planet (with a orbiting the Sun-like star HD is an instrument minimum of 65 Earth ) orbiting 10180. with unrivalled in 2200 days. The other would be the least measurement massive ever discovered, with a The researchers also have stability and mass of about 1.4 times that of the Earth. tantalising evidence that two great precision It is very close to its host star, at just 2 other planets may be present, and is the percent of the Earth–Sun distance. One one of which would have the world’s most “year” on this planet would last only 1.18 lowest mass ever found. This successful Earth-days. would make the system similar exoplanet to our in terms of hunter. the number of planets (seven as Thanks to the compared to the Solar System’s 190 individual eight planets). Furthermore, HARPS the team also found evidence measurements, that the distances of the planets t h e ESO 3.6 m telescope, from their star follow a regular pattern, as also seen in our Solar System. astronomers detected the tiny back and “We have found what is most likely forth motions of the star caused by the the system with the most planets yet complex gravitational attractions from five discovered,” says Christophe Lovis, lead or more planets. The five strongest signals HD 10180 author of the paper reporting the result. correspond to planets with Neptune-like Image Credit: ESO and Digitized Sky Survey 2. masses — between 13 and 25 Earth masses Acknowledgment: Davide De Martin The team of astronomers used the HARPS — which orbit the star with periods ranging spectrograph, attached to ESO’s 3.6-metre from about 6 to 600 days. These planets telescope at La Silla, Chile, for a six-year- are located between 0.06 and 1.4 times the Continued on page 6 Back to Basics: Synchronous rotation ynchronous rotation is a phenomenon planet, which creates frictions that dissipate causes rotational energy to be lost. that occurs when a satellite (moon) energy and slow down the moon’s rotation. Eventually, over eons, the moon slows orbitsS its planet close enough so that This slowing-down is dependent on the down until its rotation about its axis exactly the period of rotation of the satellite is magnitude of the forces of friction that are matches its and keeping synchronized with its period of revolution. impeding the re-alignment of the bulges: it always the same face toward the planet. Seen from the planet, it always presents can be greater in case of a highly rigid body This is called tidal synchronization the same face. Or seen from the satellite, or it can be less important if the bulges are the planet appears fixed in the sky. fluid, which is the case for the Earth with As a matter of fact, all moons in the solar its oceanic and atmospheric tides. system are synchronized with their planets, Gravitational attraction between two The result of these constantly changing tidal the only known exception being Hyperion, celestial bodies produces tidal forces that distortions is the production of heat that one of the many moons of Saturn. tend to stretch them in the In the case of Pluto and its moon Charon, it direction of the axis planet- goes one step further, both are tidally locked moon. This is because the to each other: viewed from Pluto’s surface gravitational forces on the Charon has always the same position in the near sides of the bodies are sky and, viewed from Charon’s surface, greater than the gravitational Pluto too has always the same position in forces at the centres of these the sky. bodies and even greater than Syncrhonous rotation can be achieved the ones on the far sides. pretty quickly when the mass difference If the bodies in question are between moon and planet is large enough: sufficiently flexible and if the it is estimated that it took ony a few tens of tidal forces are sufficiently millions of years for our Moon to become strong these bodies will be tidally locked. slightly deformed. When it comes to Earth, it too is slowing As the majority of the moons down. It is estimated that the energy are spherical under the dissipated by the tidal forces caused by the action of their own gravity, Moon and the Sun is approximately 2.75 the action of the tidal terawatt, which brings about a lengthening forces give them a slightly of Earth’s of approximately 2 ms: one elongated shape (football The far side of the Moon day, billions of years from now, Earth too shaped) pointing toward the planet. Image Credit: NASA, Apollo 16 crew will be in synchronous rotation with the As the moon turns the tidal forces try Moon. to keep the bulges aligned with its Jean-Luc Gaubicher

Observing the night skies from Sydney October 2010 47 Tucanae (NGC 104) Constellation name: Tucana A globular cluster, 16,000 light years away, 47 Tuc is a naked eye object shining at magnitude 4.5. It is the second brightest cluster after Omega Centauri but its core is much more compact and is very bright

The Sculptor (NGC 253) Constellation name: Sculptor NGC 253 is a large spiral galaxy seen almost edge-on. that is approximately 11 millions ligt-years distant. Itis a “starburtst galaxy” where star formation is taking place a t an exceptionaly high rate. At magnitude NGC 253 can be seen through binoculars under dak skies but larger telescopes are 47 Tucanae necessary to show some texture. Image Credit: ESO

Omicron Ceti (Mira) Constellation name: Cetus Omicron Ceti is the most variable star. Discovered in 1596, it was named it Mira Stella, the Wonderful Star, by Johannes Hevelius in 1662. Its magnitude varies between 3.4 and 9.3 with a periodicity of 332 days. According to AAVSO, its next maximum should take place on the 16th of this month.

November 2010 Zeta Piscium Constellation name: Pisces Zeta Piscium is a magnificent double star. Its 2 , a whight dwarf star and a pale-yellow star of magnitude 5.6 and 6.5, are separated by 24 arcseconds that can be easily resolved with a medium size telescope. The Andromeda Galaxy (M 31) Constellation name: AndromedaThe Andromeda Galaxy is part of the local cluster of the closest spirsal galaxy to us. Under dark skies it is one of the most distant object visible to the naked eye at a distance of aproximately 2.5 million light-years. A small telescope will also reveal 2 companion eliptical galaxies: M 32 and M 110.

M 15 (NGC 7078) Constellation name: Pegasus M 15 is a globular luster about 34,000 light -years away from the Earth and is estimated to be 13 old . Its 6.2 magnitude makes it a binocular object but a telescope of 200mm is necessary to resolve it in individual stars.

December 2010 The Great Barred Galaxy (NGC 1365) M 31 Constellation name: Fornax Image Credit: JL Gaubicher/ESA/ESO/ The Fornax cluster is one of the largest cluster of galaxies. One of its best known member NASA Fits Liberator is the Great Barred Galaxy. Despite its name, you will need a fairly large telescope and good conditions to view NGC 1365’s bar. Situated at a distance 56 million light- years its magnitude is around 10.3.

Omicron 2 Eridani (40 Eridani - Keid) Constellation name: EridanusOmicron 2 Eridani is an interesting triple star less than 16.5 light-years away.The primary star, a magnitude 4 orange dwarf, is easily visible to the naked eye.. The 2 other components are a magnitude 9 white dwarf and a magnitude 11 red dwarf.

NGC 1399 and NGC 1404 Constellation name: Fornax A wide-field eyepice should allow you to see another interseting view in Fornax. NGC 1399 and NGC 1404 are two elliptical galaxies that lies just a few arcminutes apart in the midst of a few other faint galaxies NGC 1365 Image Credit: ESO/IDA

Water vapour discovered on carbon star team of astronomers led by Leen instruments can change our picture clumpy structure in the dusty envelope ADecin (University of Amsterdam and completely,” says Decin. The superb around IRC+10216. The astronomers Katholieke Universiteit Leuven, Belgium) sensitivity of Herschel’s instruments has realised that ultraviolet light emitted by have found water vapour in the atmosphere revealed that the water stars can reach deep into the of a carbon star using the Herschel space around IRC+10216 varies envelope between the clumps observatory. in temperature from and break up molecules such about –200°C to 800°C, as carbon monoxide and Until now the formation of water vapour in which indicates that it silicon monoxide, releasing the atmosphere of such a star was deemed is being formed much oxygen atoms. The oxygen impossible. closer to the star than atoms then attach themselves When the astronomers discovered the comets can stably exist. to hydrogen molecules, unexpected cloud of water vapour forming water. around the old red giant star CW Leonis IRC+10216 is a red giant (IRC+10216) in 2001, they immediately star, hundreds of times the CW Leonis “This is the only began searching for the source. Sun’s size, although only Image Credit: ESA/PACS/SPIRE/MESS mechanism that Stars like IRC+10216 are known as carbon a few times its mass. It is explains the full stars and are thought not to make much 500 light years away and while it is barely range of the water’s temperature,” says water. Initially they suspected the star’s detectable at visible wavelengths, even in Decin.The closer to the star the water is heat must have been evaporating water the largest telescopes, it is the brightest star formed, the hotter it will be. from comets or even dwarf planets. in the sky in the infrared at a wavelength of Now, Herschel’s PACS and SPIRE 10µm. This is because of a huge envelope Decin and her colleagues now plan to instruments have revealed that the secret of dust that surrounds it and absorbs almost extend the observations to other carbon ingredient is ultraviolet light, because the all its visible radiation and re-emits it as stars. “We are very hopeful that Herschel water is too hot to have come from the infrared light. will find the same situations around those destruction of icy celestial bodies. It is in this envelope that the water vapour stars too,” she says. has been found. But how did it get there? SRON “This is a good example of how better Observations had already revealed the Netherlands Institute for space Research Life in the Blue Mountains: An Astronomer and a Politician rederick Eccleston Du Faur was born in Sir Henry Parkes emigrated to Australia FLondon in 1832 and died in Australia with his wife Clarinda in 1839. 1915. In the mid 1870s he built a country retreat He had arrived in Australia in 1853 and on land in the Blue Mountains which he was chief draftsman in the Crown Lands named Faulconbridge after his mother, Office in the 1870s. He was a member of Martha Faulconbridge. an intellectual group, the Royal Society. On his death in 1896 his family declined the pomp and ceremony of a State funeral. He formed a strong attachment to the Blue Woodford Astronomicla Station Mountains landscape and purchased land The event attracted a vast array of Picture by Joseph Bischoff at Mt Wilson in 1875. dignitaries and citizens. The mourners In 1874 Du Faur was chosen as one of the filled six carriages of the special funeral official observers of the Transit of Venus, train that bore his body from the Sydney expected on 9th December that year, and Mortuary Station to Faulconbridge. last observed in 1769 by Captain James There Sir Henry was laid to rest beside his Cook. wife in the small cemetery he had earlier Of the four government Astronomical set aside from his estate as sacred ground. Stations established, the one at Woodford Photos of him and his funeral cortege are was set up in the seven hectare former shown. police paddock to the west of Alfred Fairfax’s house. The observation was By a strange twist of fate politics and successfully accomplished on the expected astronomy somehow share a link, the town date. of Parkes being the home of the famous radio telescope. Du Faur introduced the artist William Arthur Boyd Piguenit (1836–1914) and landscape photographer Joseph Bischoff to Grose Sir Henry Parkes at Faulconbridge Valley in 1875. (Springwood Historical Society)

The funeral cortege of Sir Henry Parkes at Central Station on 29 April 1896 (Springwood Historical Society) Richest Planetary System Discovered Continued from page 3 massive planets there Furthermore, the is that there is a relationship between the “This object causes a wobble of its star system probably has no Jupiter-like gas mass of a planetary system and the mass of only about 3 km/hour— slower than giant. In addition, all the planets seem to and chemical content of its host star. All walking speed — and this motion is very have almost circular orbits. very massive planetary systems are found hard to measure,” says team member around massive and metal-rich stars, while Damien Ségransan. Using the new discovery as well as data for the four lowest-mass systems are found If confirmed, this object would be another other planetary systems, the astronomers around lower-mass and metal-poor stars. example of a hot rocky planet, similar to found an equivalent of the Titius–Bode Such properties confirm current theoretical Corot-7b. law that exists in our Solar System: the models. The newly discovered system of planets distances of the planets from their star The discovery was announced on 24 August around HD 10180 is unique in several seem to follow a regular pattern. “This 2010 at the international colloquium respects. First of all, with at least five could be a signature of the formation “Detection and dynamics of transiting Neptune-like planets lying within a distance process of these planetary systems,” says ”, at the Observatoire de Haute- equivalent to the orbit of Mars, this system team member Michel Mayor. Provence, France. is more populated than our Solar System Another important result found by the For more details go to: in its inner region, and has many more astronomers while studying these systems http://ww.eso.org/public/news/eso1035/ St Ives North PS Star Night his evening was organised by Paul a scope it turned out each one came to One boy said he could see the ice cap on TBrooks who is a parent at the school have a look, with a parent in tow, and Mars, while an adult seriously enquired and was held on 11th August 2010. they moved on very quickly. There was a “Where does the sun go in the evening?” teacher standing by to assist when this was This Star night turned out to be a worthwhile required. The evening lasted until about 8pm when event with a very clear sky, the children, most people had left and by 8.30pm the parents and teachers enjoyed themselves Initially we looked at Venus, Mars and sky was clouded over. and found it an informative evening and Saturn and later on some shifted to everything ran very smoothly. formations such as the Jewel Box. We all enjoyed the evening and learnt how The children were very impressed with to do it better next time. Although only 3 of us from NSAS Saturn, just with its shape and its rings. Peter Korber eventually made it to the school, we were Some were amazed by the gaps between welcomed with offers of food and coffee or the rings and many expressed astonishment tea and, later on, were presented with a bag at seeing Saturn “in the flesh”. of goodies to tie us over for the evening.; a very warm welcome. For many it was the first time they had ever looked through a telescope and this was an While Paul Brooks had organised for exciting experience for both children and specific intervals for each child to beat parents.

Pictures by Lara Kepitis

The Binocular and Telescope Shop 84 Wentworth Park Road Glebe NSW 2037 Phone: (02) 9518 7255 Sausage Sizzle at Tarrumarra

Find the Secret Message by Roy Jordan Find and circle all of the Astronomy related words that are hidden in the grid. The remaining letters spell a secret message. T H T F A R C E C A P S P E L F A I R S ANDROMEDA GALAXY MOON O R B I T S R T S P M E M I E V R E S O APOGEE ASTEROID NEBULA N T O D S P S A E A R I G O O T I Q H R ASTRONOMER ORBIT S S F I R A U O T I T H L N O R O U E E ATMOSPHERE R O T O E C N E G S T E R K U N B I C D AURORA PERIGEE A L E R M E O E P Y Y E L A Y B O N A G BINARY STAR POLARIS S A C E O S E N E O P R T L L W N O P I BLACK HOLE PROXIMA CENTAURI PULSARS L R L T N H T A S U C N A E I S A X S A CONSTELLATION CORONA QUASARS U W I S O U R R S T E S F N O T M Y P N CRATER RED GIANT P I P A R T A H E C E R E L I M E A E T DEEP SPACE SATELLITE O N S P T T O N A G A L A L W B T U E G ECLIPSE SOLAR SYSTEM A D E O S L A M A W S R L Y E S E R D A EQUINOX SOLAR WIND L R D G A E I L D R S A E A T T O O N L GALAXIES SPACE SHUTTLE SPACECRAFT U E I E E X A E A Y I L N L T I R R C I GALILEO GRAVITY STARS B T T E O X T S S I R A L O P I V A E L HUBBLE SUN E A A R I I A T M O S P H E R E O A S E KEPLER SUPERNOVA N R P E H U E L O H K C A L B O K N R O LIGHT YEAR TELESCOPE R C S W Q M M U N I V E R S E S C T A G METEOR TIDES A N D R O M E D A G A L A X Y R O N P G MILKY WAY UNIVERSE WHITE DWARF Solution: Use a mirror to discover the secret message Armstrong Neil was Moon the on foot set to person first The

Reflections is published quarterly by the Northern Sydney Astronomical Society Inc PO Box 56 Lane Cove 1595 Tel: 0423 971 374 E-mail: [email protected] Web site: www.nsas.org.au