WESTERN AUSTRALIAN AASTRONOMSTRONOMYY ALMANACALMANAC FREEINCLUDES CD

TheThe reallyreally usefuluseful guideguide toto thethe wonderswonders ofof thethe nightnight skysky

Highlights: Mid January C/2005 P1 (McNaught)(McNaught) maymay bebe visiblevisible March 4 Total Eclipse of the April 20 visible in daytime May 20 Venus visible in daytime June Two full July 17 Lunar of Regulus June 18 Venus visible in daytime August 28 Total Eclipse of the Moon October 7 Venus visible in daytime November 6 Venus visible in daytime 20072007 2007

JANUARY 2007 FEBRUARY 2007 MARCH 2007 Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat 123456 123 123

7 8 9 10 11 12 13 45678910 45678910

14 15 16 17 18 19 20 11 12 13 14 15 16 17 11 12 13 14 15 16 17

21 22 23 24 25 26 27 18 19 20 21 22 23 24 18 19 20 21 22 23 24

28 29 30 31 25 26 27 28 25 26 27 28 29 30 31

APRIL 2007 MAY 2007 JUNE 2007 Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat 1234567 12345 12

8 9 10 11 12 13 14 6 7 8 9 10 11 12 3456789

15 16 17 18 19 20 21 13 14 15 16 17 18 19 10 11 12 13 14 15 16

22 23 24 25 26 27 28 20 21 22 23 24 25 26 17 18 19 20 21 22 23

29 30 27 28 29 30 31 24 25 26 27 28 29 30

JULY 2007 AUGUST 2007 SEPTEMBER 2007 Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat 1234567 1234 30 1

8 9 10 11 12 13 14 5 6 7 8 91011 2345678

15 16 17 18 19 20 21 12 13 14 15 16 17 18 9101112131415

22 23 24 25 26 27 28 19 20 21 22 23 24 25 16 17 18 19 20 21 22

29 30 31 26 27 28 29 30 31 23 24 25 26 27 28 29

OCTOBER 2007 NOVEMBER 2007 2007 Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat 123456 123 30 31 1

7 8 9 10 11 12 13 45678910 2345678

14 15 16 17 18 19 20 11 12 13 14 15 16 17 9101112131415

21 22 23 24 25 26 27 18 19 20 21 22 23 24 16 17 18 19 20 21 22

28 29 30 31 25 26 27 28 29 30 23 24 25 26 27 28 29

New Moon First Quarter Full Moon Last Quarter WESTERN AUSTRALIAN AASTRONOMSTRONOMYY ALMANACALMANAC 2007CONTENTS Introduction 3 Getting Started 4 How To Use This Almanac 6 January 8 February 12 March 16 April 20 May 24 June 28 July 32 August 36 September 40 October 44 November 48 December 52 Special Events – Eclipses & 56 Information 60 & Non-Stellar Objects 95 Background & General Information 99 Western Australian Places of Astronomical Interest 120

© Perth Observatory 2006 This book is copyright. Apart from any fair dealings for purposes of private study, criticism or review, as permitted under the Copyright Act, no part may be reproduced by any process without written permission. Inquiries should be made to the publishers. ISBN 0-9581963-6-2 Published in December 2006 by: Perth Observatory, 337 Walnut Rd, Bickley 6076, Western Australia Phone: (08) 9293 8255 Fax: (08) 9293 8138 Website: www.perthobservatory.wa.gov.au Email: [email protected] Western Australian Astronomy Almanac 2007 may be purchased directly from Perth Observatory, Phone (08) 9293 8255, or from all good booksellers. Disclaimer: Perth Observatory has gone to a great deal of effort to ensure that all the details in this almanac are correct. However, the Perth Observatory cannot be held responsible for any eventuality arising out of the use of the data herein. It is advisable to contact Perth Observatory directly with your astronomical data requirements in order to maximise their quality. Please note that charges apply for such consultancies. ACKNOWLEDGEMENTS

Thanks to Perth Observatory staff for proof reading and input, Peter Pieloor of Ali B Design for all the graphic design work, and the taxpayers of Western Australia who have supported Perth Observatory for over a century.

Information for this almanac was adapted from the following sources: ‘Astronomical Almanac for the 2007’, (US Naval Observatory/H.M. Nautical Almanac Office, Rutherford Appleton Laboratory). ‘Astronomical Tables of the Sun, Moon and ’, 2nd ed., 1995, by Jean Meeus, Willmann-Bell Inc. ‘Astronomy and Astrophysics in the New Millennium’, National Research Council USA, National Academy Press. ‘The Cambridge Guide to the ’, 1995, by Michael E Bakich, Cambridge University Press. ‘Eclipse! The What, Where, When, Why and How Guide to Watching Solar and Lunar Eclipses’, 1997, by Philip Harrington, John Wiley & Sons, Inc. ‘Explanatory Supplement to the Astronomical Almanac’, 1992, ed. by P. K. Seidelmann, University Science Books, Mill Valley, , USA. ‘Frequently Asked Questions About Calendars’, by Claus Tondering, 2005. ‘Mathematical Astronomy Morsels’, 1997, by Jean Meeus, Willmann-Bell Inc. ‘More Mathematical Astronomy Morsels’, 2002, by Jean Meeus, Willmann-Bell Inc. ‘The Southern Sky Guide’, 1993, by David Ellyard & Wil Tirion, Cambridge University Press. ‘Total Eclipses: Science, Observations, Myths and Legends’, 1999, by Pierre Guillermier and Serge Koutchmy, Springer – Praxis Series in Astronomy. Heavens Above website http://www.heavens above.com ICQ/CBAT/MPC World Wide Web pages http://cfa-www.harvard.edu/iau/ International Meteor Organization http://www.imo.net/ JPL Solar Systems Dynamics Group http://ssd.jpl.nasa.gov/ NASA National Space Science Data Center http://nssdc.gsfc.nasa.gov/planetary Resolutions 5 and 6 adopted at IAU XXVIth General Assembly in Prague, on August 24, 2006. http://www.iau.org/Resolutions_at_GA-XXVI.340.0.html SIMBAD database, operated at CDS, Strasbourg, France http://simbad.u-strasbg.fr/sim-fid.pl Sky and Telescope magazine http://skyandtelescope.com/ United States Naval Observatory http://www.usno.navy.mil US Geological Survey Planetary Nomenclature http://planetarynames.wr.usgs.gov/ ICE version 0.51, US Naval Observatory, Nautical Almanac Office Sky Charts – Cartes du Ciel version 2.76 by Patrick Chevalley Starry Night Pro, version 3.0.2, Sienna Software Inc. . Front cover image: This features the giant -forming region in the southern sky known as the Carina (NGC3372). This image is created by combining the light from 3 different filters tracing emission from oxygen (blue), (green), and sulphur (red). The colour is also representative of the in the ionized gas: blue is relatively hot and red is cooler. The Carina Nebula is one of the most prominent features of the Southern visible to the . Its distance from us is about 8,000 light , and it has a diameter of over 200 light years. In normal colour images it is generally red in colour due to the fluorescent emission from of hydrogen. This emission from the gaseous nebula is caused by intense radiation from young, hot stars in the clusters within it. In fact, the Carina Nebula is the region nearest to the Sun where there are examples of the most massive stars known (spectral type O3), with surface 10 times and 100 times those of the Sun. The bright star near the centre of the image is Eta Carinae, which is one of the most massive and luminous stars known. Acknowledgement: Nathan Smith, University of Minnesota/NOAO//NSF

2 INTRODUCTION

It was a case of back to the future for astronomy in 2006. The controversy concerning ’s redefinition from a to dwarf planet is not unique in astronomical history – similar controversy accompanied the redefinition of the “planets” Ceres, Pallas, Juno, Vesta, and others, to minor planets/ in the mid 1800’s. What is not controversial is the need for appropriate definitions, or more precisely a “taxonomical” system for planet-like objects. This will aid our understanding and facilitate advancement in this field and the never-ending discoveries in our Solar System (and the Milky Way ) are forcing us in this direction. The term planet conjures images of a diverse range of astronomical objects that is as unconstructive to astronomers as a zoological garden with all enclosures labelled “animal” is to zoologists.

It is clear that the “planet-definition” debate will continue into 2007 and beyond – and well it should. The current debate has focussed on a definition applicable only to the Solar System. This is justifiable as Solar System objects are closer and thus, in principle, easier to observe and discern their characteristics. However, this limitation has not restrained controversy to date. In fact, it is easy to foresee that the debate will get more problematic as implicitly related to the definition of a planet is the definition of a moon. At one time in the current planet debate it was mooted that Charon, the large moon of Pluto (nearly half Pluto’s diameter) should be classified a planet and the Pluto-Charon system should be classified a double planet. However, there are several Solar System moons larger than Pluto, including our Moon (Luna). And why should a planet definition be restricted to the Solar System – free floating objects that have too little to become stars have been found in the Milky Way, and convincing evidence has been found for over 200 planets orbiting near, and distant, stars.

Clearly, the “planet” debate has a long way to go and it is very likely that future observations will reveal new objects that further disorientate our preconceptions on this issue.

There is plenty to see in the night sky in 2007. Comet C/2005 P1 (McNaught) was discovered in August 2006 and current estimates suggest it may be just visible to the unaided eye, low in the WSW sky, in mid January. Please note that comet brightness is notoriously variable!

Comet C/2005 P1 (McNaught) may be visible in mid January Two lunar eclipses are visible from WA in 2007. In the first of these only the early stages are visible because Moonset occurs before mid eclipse. The lunar eclipse appears more promising as the Moon rises 45 minutes before mid eclipse.

TOTAL ECLIPSE of the MOON March 4 and August 28 Can you observe any celestial objects other than the Sun and Moon in the daytime? Yes, people with average eyesight should be able to detect the bright planet Venus. But you must know its position because the glare of the daytime sky severely reduces its conspicuousness. One way to overcome this is to try to observe it when it’s close to the Moon. This occurs on April 20, May 20, June 18, Oct 7 and Nov 6. So on these dates use the Moon as a position reference and slowly scan around it in order to find Venus. Remember: Do NOT look at the Sun.

VENUS VISIBLE in DAYTIME April 20, May 20, June 18, Oct 7 and Nov 6

In June the Moon will have Full phases on two occasions. This occurrence is not particularly rare; it recurs about every 21/4 years and depends on the time zone. For example, in 2007 Australia has two full Moons in June and New Zealand has two full moons in July. Increasingly, the second Full Moon in a month is called a ‘Blue Moon’ but this is a recent expression and can be traced back to a US farming almanac from about 50 years ago.

Two Full Moons in June Remember to keep an eye to the sky. While this almanac will help you plan your observing sessions based on predicable phenomenon, the sky is full of wondrous unpredictable events that happen at any time.

James Biggs, BSc (hons) PhD FRAS MAAS MIAU FASA Government Astronomer for Western Australia, Director of Perth Observatory, and Adjunct Associate Professor, Curtin University of Technology.

3 GETTING STARTED

Competence requires practice. So if you want to These detailed units are used in the tables of accurate positions appreciate the night sky beyond the level of simple of objects in the sky; for example, see the Section Solar System wonderment (which we might add is a reasonable thing in Information. Also note the way that astronomers write decimal itself) then you have to practice – you have to get out and angles – the symbol is always placed after its integer part, eg 1 observe, and prepare yourself so that you know what you /2˚ = 30’ = 0.˚5, not 0.5˚. Another system to define angular are observing. positions on the sky uses time-based units: , minutes and . This type of unit is convenient because the sky moves Here are some steps that you should take in order to gain one rotation about every 24 hours, similar to the Sun. In this a deeper appreciation of the night sky. system, one complete rotation corresponds to 24 hours ■ Read astronomy books and other media (denoted 24h) and the is subdivided into minutes and seconds in the conventional way. Note: This system is used for It’s best to be prepared before you step outside to observe. This positions on the sky, for example . In order to means obtaining some reliable background information about measure positional differences the system based on degrees, what there is to view, in which direction, what time it’s visible arcminutes and arcseconds should be used. and so on. This Almanac is a great place to start. It’s designed to assist star viewing. Even when you are more expert you can ■ Join an astronomy society consult it for the information that will assist your nights At an astronomy society you will meet a diverse range of people observing. There are also many websites, magazines, books, who have in common a great appreciation for and fascination CDs and videos that can assist you. We have listed some useful with astronomy. The more established members are a great websites in the Section Background and General Information source of knowledge not only about the sky, but also that can get you started and they also have references to instruments and observing sites. These societies can also provide resources in other media. enjoyable learning opportunities with formal and semi-formal A planisphere is a useful tool. It has a representation of the stars lectures on astronomical topics, viewing nights, camps for star and constellations visible for any night of the year. Make sure viewing and the like. The viewing nights also present an you purchase the correct one for your latitude. opportunity to learn about telescopes from the people who already own one. Some local societies are listed in the Section One important issue in becoming familiar with the sky is size. Western Australian Places of Astronomical Interest. Astronomers measure distances across the sky in degrees. We all know that in a circle there are 360º. However this is rather large ■ Basic Observing and not easily applicable to star viewing. There is an easy way to estimate smaller angles. Stretch out your arm in front of you. A lot of star viewing occurs incidentally, while putting out the Open your hand and extend your fingers. With your arm rubbish bin, driving home late from a trip to the country and so outstretched, the angle between the tip of your thumb on. You can see some spectacular sights when you least expect and tip of your little finger is about 20º. Also, the it. Some of these are discussed in the Section Background and width of your thumb is about 1 to 2º. Alternatively, General Information. However, to get a deeper appreciation of the night sky you have to observe regularly. the Moon provides a stationary reference being 2˚ about 0.˚5 across. In fact, you can use the Moon It’s also best to prepare yourself in advance. Remember -prior to ‘calibrate’ your extended arm and hand planning and preparation prevents poor performance. angle measuring system. First, you should try to find a safe and suitable site. It should be For smaller distances across the sky, 1º is away from the glare of lights so that your eyes have the best divided into 60 minutes of arc, or 60’. chance to become dark adapted. It is probably best to do this in One minute of arc is further divided into the daytime. Some astronomical societies have observatories or 60 seconds of arc, or 60”. The Moon viewing sites out in the country that members can use. Also, if is approximately 0.˚5 or 30’ across. observing alone or in a small group always inform your friends

20˚ 2˚

4 and family and have some form of mobile communication in (should any be around), star clusters and vistas rich in case of an emergency. stars especially along the Milky Way.

Read your almanacs and reference books, or run your computer ■ Buying a telescope programs to find out what’s where and when, then make a list Eventually, if you’ve enjoyed doing all the things mentioned of things to see and do, up at your observing site and get above you will probably want to buy your own telescope. some equipment to make yourself comfortable such as a chair Beware of any telescope that is advertised promoting its high and blanket well before it gets dark. Also, it’s advisable to wear magnification. These are probably built for a price, and not stout shoes to protect your feet. quality. It probably does have a high magnification, but what It also pays to inquire about the weather beforehand. You may you will end up magnifying is the distortion in the telescope and need to dress warmly – you will probably be exposed to the atmosphere. Read widely about telescopes and purchase from a breeze and this may create a wind chill factor that can make reputable business. conditions cool even in summer. Also, star viewing is a rather The subject of astronomical telescopes is quite large and only a low energy activity. This has the benefit that star viewing very brief discussion is presented here. Telescopes come in three presents little restriction with regard to physical fitness - but basic types: keeping your body warm is an issue. If the weather is warm or still, insect repellent may be required. • refractors – uses lenses, • reflectors – uses a concave mirror to focus light, and Whilst star viewing is not a strenuous activity muscle strains can • catadioptrics – part reflecting telescope that has a occur if your body is contorted in order to view through a correcting lens at the top to form the image. Most telescope eyepiece or the like. In your planning think about catadioptrics are of the Schmidt-Cassegrain design and what you will be doing. A simple folding chair may be very these are quite a popular and useful design. useful to minimise the risk of strain injuries. A sturdy mount is necessary in order to keep the image stable. Bring some spares. Batteries for your torch (very low power, or A motor drive is also very useful as it allows your telescope to lens covered with red cellophane), spare cables etc, and food track celestial objects (assuming it is aligned correctly). This and drink for the humans! eliminates the tedious task of winding knobs in order to keep Being organised means that there will be less need to rush and objects in the field of view and allows you to concentrate on less possibility of mistakes or accidents during star viewing. astronomy.

■ Keep it simple Refractor Don’t rush out to buy a telescope! There are a lot of telescopes that have been used once then never used again.

Become familiar with what is visible to the unaided eye. In fact, Objective the eye is the best ‘instrument’ to view large sections of the sky Lens such as those of size. This also gives you an appreciation of the location of stars and constellations and at what season and time they are visible. Eyepiece Eyepiece Objects that are visible with the unaided eye are the Moon and Lens Lens the five brightest planets, shooting stars (meteors), , and more rarely, meteor showers, bright comets and auroras. Reflector – Newtonian Plane ■ Optical Instruments Mirror Binoculars are a good instrument to start with. They are mass produced and this means that generally their optical quality is quite good, and are relatively inexpensive. Concave They come in a variety of sizes. 7 x 50 binoculars are a cost Parabolic Mirror effective choice. The 7 refers to their magnification and 50 is the width of the lens in millimetres.

Binoculars need to be held steady in order to minimise image Convex Reflector – Cassegrain shake. This can be done by leaning up against a tree, or wall, or Parabolic mounting them on a tripod. Mirror Concave Parabolic More detail is visible when using binoculars as compared to the Mirror unaided eye. This is a simple fact of physics – the wider the aperture the more detail that can be seen. Also, fainter objects become detectable using larger collecting areas; the pupil in the human eye has an aperture of about 7mm, compared to tens of millimetres for binoculars. Sights to see with binoculars Eyepiece Lens include the craters of the Moon, the moons of , bright 5 HOW TO USE THIS ALMANAC

The majority of this almanac is dedicated to the provision of detailed information about what is to be seen and 2007 where it is located for each month. Following that is a JANUARY Highlights SUN+MOON RISE/SET SUN MOON Transit for this section providing details about very rare and/or unusual ) h m h m h m (%) HIGHLIGHTS Rise Azimuth Twlght Time Set Azimuth Twlght˚ Rise Set Illumintn ) h m h m h m ( visible low in western evening h m ( ˚ Mercury month twilight at end of month. 1 0514 118 0334 1220 1926 242 2105 1733 0230 90 events. Finally, the later sections provide background and 2 0514 118 0335 1220 1926 242 2105 1838 0323 95 Venus clearly visible in the western evening 3 0515 118 0336 1221 1926 242 2105 1934 0422 99 twilight. 4 0516 118 0337 1221 1926 242 2105 2022 0526 100 ars visible low in the eastern morning reference information relevant for this year, as well as M 5 0517 118 0338 1222 1927 242 2105 2102 0631 99 twilight. 6 0517 117 0339 1222 1927 243 2105 2135 0734 95 rises in the east before . Jupiter 7 0518 117 0340 1223 1927 243 2105 2204 0835 90 more general astronomical information. Saturn visible after midnight. 8 0519 117 0341 1223 1927 243 2105 2230 0932 84 9 0520 117 0342 1223 1927 243 2105 2254 1027 76 Sun 10 0521 117 0343 1224 1927 243 2104 2318 1121 67 11 0522 117 0344 1224 1927 243 2104 2343 1215 58 DIARY 12 0523 116 0345 1225 1927 244 2104 DNR 1310 49 & Moon Day Hour 13 0523 116 0346 1225 1926 244 2103 0011 1408 39 Full Moon 322 14 0524 116 0347 1225 1926 244 2103 0043 1508 30 Monthly Sections 4 04 at perihelion Antares 15 0525 116 0348 1226 1926 244 2103 0120 1609 22 Rise/Set 5 12 Jupiter 5º N. of 16 0526 116 0350 1226 1926 244 2102 0205 1711 14 17 0527 115 0351 1226 1926 245 2102 0258 1809 8 7 02 Saturn 0.º9 S. of Moon Regulus 1.º2 S. of Moon 18 0528 115 0352 122