Affiliated Societies are welcome to reproduce any item in this email newsletter or on the RASNZ website http://www.rasnz.org.nz/ in their own newsletters provided an acknowledgement of the source is also included.

Contents

1. Gary Wilmshurst (1949 - 2011)
2. Comet Lovejoy C/2011 W3
3. The Solar System in February
4. Council and Executive Nominations
5. Murray Geddes Memorial Prize Nominations
6. Stardate South Island - February 17-19
7. Wellington Astro-music Concert 16 March
8. NACAA 2012 - April 6-9
9. RASNZ Conference June 15-17
10. Leap Second on June 30
11. Do We Need Leap Seconds?
12. Reverend George Burgess?
13. White Dwarf Merger Makes Type I Supernova
14. A Planet for Every Star
15. Asteroid Moa
16. How to Join the RASNZ
17. Gifford-Eiby Lecture Fund
18. Kingdon-Tomlinson Fund

1. Gary Wilmshurst (1949 - 2011)

Gary Wilmshurst unexpectedly passed away on the 28th of December 2011. Gary had been a member of RASNZ and served on Council. He was also a member of the Wellington Astronomical Society (WAS) and was President during the 1980s. Gary also served as a representative of the RASNZ on the Carter Observatory Board.

Gary had a keen interest in astronomy and space exploration. I first met Gary at Carter as telescope operator and presenter and over the years worked with Gary on many WAS/Carter projects. Gary was also on the organising committees for the RASNZ conferences that were held in Wellington.

His favourite topics were the latest images and results from the many NASA probes and missions during the 1980s and 1990s. Through this interest Gary built a long-standing relationship with Bob Mitchell of NASA´s Jet Propulsion Laboratory. This resulted in Bob travelling to New Zealand and speaking at RASNZ conferences.

Gary was very keen on promoting science and astronomy with young people. His enthusiasm, smile and great sense of humour will be missed.

-- John Field.

2. Comet Lovejoy C/2011 W3

Comet Lovejoy provided astro-photographers with a superb subject over the Christmas-New Year holidays -- those who had clear dawn skies, that is. Not unexpectedly, the comet's nucleus disintegrated during its close approach to the sun's surface. The dust from its fragmentation produced the long narrow tail that delighted sky watchers.

A puff of dust from a comet's "dirty snowball" nucleus spreads away from the sun along a line. The speed the dust moves away depends on the particle size. The gravity acting on a particle varies inversely as the square of the distance from the sun. The intensity of sunlight varies in the same way but with an outward push. So a particle "feels" a lesser gravitational attraction toward the sun due to the sunlight pressure. It thus moves in a different orbit, as though the sun's gravity was weakened. The smaller the particle, the greater is the acceleration away from the sun due to light pressure.

The line or band of dust is called a synchrone ("same time") as all the dust was ejected together. By analysing the brightness and angles of synchrones it is possible to calculate when the dust was emitted and how big the particles are.

Zdenek Sekanina of the Jet Propulsion Laboratory has done this analysis for Comet Lovejoy. Writing in Central Bureau for Astronomical Telegrams Electronic Telegram No. 2967, 2012 January 6, Sekanina found that most of Comet Lovejoy's tail was the product of a major outburst, or a series of outbursts, that peaked during a relatively short period of time centred on Dec. 17.6 +/-0.4 UT. That was 1-2 days after perihelion.

The bright part of the synchrone contained dust particles larger than about 30 microns in diameter (with radiation pressure acceleration parameter, beta, <0.04) on Dec. 19-20, larger than about 40 microns (beta <0.03) on Dec. 24, larger than about 80 microns (beta <0.015) on Dec. 29, and larger than about 120 microns (beta <0.01) on Jan. 3 (when the bright part is understood to be the northern-most 40' of the feature).

The synchrone approximately coincided with the line of symmetry to the much fainter quasi-parabolic envelope of additional ejecta, consisting of a smaller number of dust particles that -- upon their ejection (on or before Dec. 17.6) -- acquired lateral velocities mostly several tens of m/s, with an upper limit of 200 m/s. The sharp spike at the sunward end of the synchrone, the site of the most massive fragments (possibly boulder-sized or larger) are located, shows that their separation velocities were extremely low.

Sekanina noted that no images showed a second tail produced by new dust from the nucleus. It would have been expected to the south of the synchrone, making an angle of 5-6 deg to it. Also there was a dramatic change in the comet's appearance between Dec. 19 and 20. The comet's nuclear condensation -- the bright cloud around the nucleus -- disappeared on Dec. 20. All this suggests that the comet sustained a severe damage to its nucleus as the source of activity.

Sekanina concluded: "The outburst(s) apparently constituted part of the rapidly-progressing process of cataclysmic fragmentation that was continuing past Dec. 19.4 UT but was essentially completed by Dec. 20.3. The drop in brightness from Dec. 20 on is, in this scenario, understood as reflecting basically the rate of dispersal in space of the dust ejecta released during the Dec. 16-20 period of the comet's activity."

"It appears that, brightness-wise, C/2011 W3 is rivalling the headless sungrazer C/1887 B1, whose tail was visually detected until about 19 days after perihelion. However, C/2011 W3 is doing a little better in terms of the post-perihelion survival of an active nucleus, as comet C/1887 B1 was found to have lasted for only about 6 hours after its perihelion passage (Sekanina 1984, Icarus 58, 81)."

Sekanina's analysis used two images taken by J. Ebr et al on Dec. 19.37 and 20.33 UT with a 0.3-m f/10 Schmidt-Cassegrain reflector, a robotic remotely-controlled telescope located at the Pierre Auger Observatory at Malargue, Argentina (as reported by J. Cerny at http://www.kommet.cz); and eleven images were taken by Robert H. McNaught on Dec. 23.75, 24.74, and daily between Dec. 26.74 and Jan. 3.73 UT with the Uppsala 0.5-m f/3.5 Schmidt telescope at the Siding Spring Observatory See http://msowww.anu.edu.au/~rmn/C2011W3.htm.

For more on Comet Lovejoy see http://www.eso.org/public/news/eso1153/ http://www.astroarts.jp/photo-gallery/data/rakudaoyaji/6797.jpg

3. The Solar System in February

The usual notes on the visibility of the Planets for February 2012 are on the RASNZ web site: http://www.rasnz.org.nz/SolarSys/Feb_12.htm. Notes for March 2012 will be on line in a few days.

The planets in february

Both Venus and Jupiter will be easily visible to the west and northwest shortly after sunset. They will get closer to one another during the month.

Mars will become easily visible in the late evening to the northeast by the end of February. Saturn also rises before midnight, and should be visible low to the east at midnight be the end of the month. It will be better seen in the morning sky.

Mercury is at superior conjunction with the Sun on the 7th. At its best Mercury will set about 30 minutes after the Sun at the end of February, so is not likely to be visible in the evening twilight.

(433) EROS, will make a close approach to the Earth at the end of January and beginning of February. It will reach magnitude 8.6 at its brightest so be in the reach of binoculars. During February Eros will be in New Zealand skies all night.

Venus and JUPITER in the EARLY EVENING SKY

Venus sets a little over 90 minutes after the Sun in February, so will be obvious but low to the west soon after sunset. An hour after sunset the planet will be about 6 degrees up early in the month and less than 5 degrees by the end of February. An hour after sunset will be close to the end of nautical twilight, so there will still be considerable brightening of the sky to the west.

At the beginning of February, Venus will be in Aquarius but by the 3rd will have moved into Pisces, which it crosses during the rest of the month.

Venus starts February just under 6 degrees to the lower right of Vesta, magnitude 8.2. As it moves away from the asteroid, Venus will close in on Uranus, magnitude 5.9. The two are closest on the 10th, with Venus less than half a degree to the lower right of Uranus. It should be possible to pick up Uranus in binoculars as the sky gets darker, but of course the two planets will be getting low. There will be no star nearby which could be confused with Uranus. The two planets are no more than 5 degrees apart from the 6th to the 14th of February.

A few evenings later, Venus passes the asteroid, or dwarf planet, Ceres. The two are closest on the 15th, with Ceres just over 7 degrees above and slightly to the left of Venus. At magnitude 9.2 Ceres will be very difficult to spot in binoculars with the sky not completely dark.

Jupiter sets about 10.30 pm by the end of February and will be in Aries. It will be moving to the east more slowly than Venus so that by the end of February the two will be about 12.5 degrees apart. Thus they will be beginning to form a fine pair to the west.

The crescent moon will be a little under 7 degrees to the right of and slightly lower than Venus on the 26th. The following night it will be less than 5 degrees to the lower right of Jupiter.

Mars and SATURN in the LATER EVENING SKY

Mars rises about 100 minutes after sunset at the beginning of February, only 20 later at the end of the month. By then it will be at a moderate altitude to the northeast in the late evening. At magnitude -1.2 it will be the brightest object in that direction and nearly as bright a Sirius.

During February, Mars will appear to be moving in a retrograde sense to the west as the faster-moving Earth begins to catch up with the planet in their orbits round the Sun. Mars starts February in Virgo but crosses into Leo on the 3rd. In Leo the planet will move towards Regulus, the two being just under 15 degrees apart by the end of the month.

On February 10 the moon, 3 days past full, will be some 9 degrees to the upper right of Mars. The previous night it will form a broad triangle with Mars and Regulus with the moon at the apex.

Mars will also be visible in the morning sky, it will be fairly low to the west at about 6am by the end of the month.

Saturn rises shortly before midnight on February 1 and about 10 pm on the 29th. Thus by then it will be visible rather low to the east by late evening. The planet will be in Virgo and some 7 degrees below Spica. Saturn is nearly a magnitude brighter than the star.

Saturn will of course also be readily visible in the morning sky at least up to about 6 am. The planet will then be to the west and considerably higher than in the evening. In the morning sky Saturn and Spica will appear to be about level with the star to the left of the planet.

The moon will be at its closest to Saturn and Spica on the night of February 12/13. At midnight the moon will be less than 1 degree from Spica and about 8 degrees from Saturn. They will be very low to the east. By the morning at about 6am, the moon will be about 3 degrees from Spica and 6 from Saturn. The three will be to the north.


Uranus sets only an hour after the Sun by the end of February. So it is not going to be an easy object. An hour after sunset on the 1st it will be some 11 degrees up to the west. Its conjunction with Venus on the 10th is likely to give an opportunity to locate the planet.

Neptune is at conjunction with the Sun on February 20, NZDT. So it will be too close to see throughout the month.

Brighter asteroids:

(1) Ceres will be low to the west in the early evening sky during February. The asteroid will be in Cetus at magnitude 9.3 to 9.2.

(4) Vesta is in Aquarius at the beginning of February but moves in Pisces by the 5th. It will be even lower than Ceres but a magnitude brighter, so a difficult object for binoculars

(433) Eros will be at its brightest, magnitude 8.6, at the end of January and during the first week in February. At its closest at the beginning of February it will be 0.179 AU from the Earth. The asteroid will be visible all night as it moves to the south. Throughout February, at 10.30 pm, it will be a little to the north of east, its altitude increasing from 19 degrees at the beginning of the month to 59 degrees at the end. More information and finder charts are available on the RASNZ web site.

Eros was the first near-Earth asteroid to be discovered. Its close approaches were used to determine its parallax and hence its and the Sun´s distance from the Earth. It seems appropriate that there should be another close approach of Eros this year with the transit of Venus in June. Prior to the observations of Eros, the best determinations of the solar distance had been made using the transits of Venus.

More details and charts for these minor planets can be found on the RASNZ web site. Follow the link to asteroids 2012.

-- Brian Loader

4. Council and Executive Nominations

New Year´s greeting to all RASNZ members,

Call for nominations to Council. Closing date for receipt: 15 March 2012 2012, being an even numbered year, is an election year for the RASNZ Council. Nominations are requested for all officers and council positions. The positions for which nominations are required are: President Incoming vice-president Executive secretary Treasurer 5 Council members. In addition the fellows need to nominate a fellows representative. Affiliated Societies will elect two representatives at the affiliated societies' committee meeting held prior to the AGM. The current president, Glen Rowe, automatically becomes a vice-president. The rules do not allow the president to serve a second consecutive term. By the terms of rule 74, nominations, including any for the fellows representative, need to be sent in writing to the Executive Secretary by 15 March 2012.

If you would like a nomination form please email me at This email address is being protected from spambots. You need JavaScript enabled to view it..

The nomination must specify the name of the candidate and the office sought. It must be signed by the proposer and seconder and be accompanied by the written consent of the nominee. The address to which nominations should be sent, as soon as possible, is: RASNZ Executive Secretary 662 Onewhero-Tuakau Bridge Road RD 2 TUAKAU 2697 A postal ballot will be held in April 2012 for any position for which the number of candidates exceeds the number of appointees required.

Regards Rory O´Keeffe, Executive Secretary, RASNZ


The Newsletter Editor and the Webmaster wouldn't mind others applying to the new Council for their jobs, either. -- Ed.

5. Murray Geddes Memorial Prize Nominations

Nominations are called for the Murray Geddes Memorial Prize 2012. The prize is awarded for contributions to astronomy in New Zealand. Normally the recipient is a resident of New Zealand. Nominations should be sent to the RASNZ Executive Secretary at the address below by 31 January 2012. R O´Keeffe, 662 Onewhero-Tuakau Bridge Road, RD 2, TUAKAU 2697; This email address is being protected from spambots. You need JavaScript enabled to view it.

6. Stardate South Island - February 17-19

Euan Mason writes: Stardate SI will be held from February 17th to 19th 2012 at Staveley, Canterbury. This celebration of the cosmos will feature our very own John Drummond as a special guest. The venue and programme are family friendly, and there is plenty of accommodation. The cost is only $12.50/person/ night, which is an absolute bargain for such a fabulous star party. For information and to register on-line, see http://www.treesandstars.com/stardate/

7. Wellington Astro-music Concert 16 March

John Percy writes: Dear astronomy colleagues anywhere near Wellington -- Toronto's Tafelmusik Baroque Orchestra is bringing "The Galileo Project" to Australia and New Zealand in March; it will be at Wellington Town Hall on 16 March 2012.

I personally had a small part in the creation of The Galileo Project -- as a 30-year supporter of Tafelmusik, and knowing of the outstanding multimedia programs that its double-bass player Alison Mackay had created, I suggested that they should do a Galileo program as part of International Year of Astronomy 2009, which marked the 400th anniversary of Galileo's development and use of the astronomical telescope. I was one of the organizers of IYA 2009.

Ms Mackay created an outstanding program, including images, narration, choreography, and music -- all memorized. It has toured Canada, the US, Mexico, and Asia, and now Australia and NZ, and Europe in the future. It's an outstanding fusion of astronomy and the arts. And it's received rave reviews.

You can find out more at: http://www.tafelmusik.org/galileo/index.htm including complete notes, some of the rave reviews, and a video excerpt or two.

There's more information about the tour at: http://www.musicaviva.com.au/whatson/international-concert-season- 2012/artists-touring/tafelmusik

I hope you will be able to attend the concert, and I hope you will tell your colleagues and friends about it. Prior to Wellington, it's being performed in major cities in Australia.

I wish I was coming with the orchestra; I remember well my visit to Wellington several years ago, and two other visits with connections to the RASNZ.

John Percy, Professor Emeritus: Astronomy & Astrophysics, University of Toronto

8. NACAA 2012 - April 6-9

The 25th National Australian Convention of Amateur Astronomers (NACAA) meets in Brisbane over Easter, April 6-9. The meeting at the University of Queensland campus is hosted by the Astronomical Association of Queensland and supported by other astronomy clubs in South East Queensland.

The sixth Trans-Tasman Symposium on Occultations and the inaugural Variable Stars South Symposium will be held as part of the NACAA programme. Those interested in attending please fill in the form at http://www.nacaa.org.au/2012/interested.


For more information see http://www.nacaa.org.au Email enquiries to This email address is being protected from spambots. You need JavaScript enabled to view it. or write to P.O. Box 188, Plumpton, NSW 2761.

9. RASNZ Conference June 15-17

The RASNZ's annual Conference is being held at the Carterton Events Centre June 15-17. The registration form is available on the RASNZ Webpage (www.rasnz.org.nz). Or it can also be accessed via RASNZ Wiki, as can the publicity brochure.

At this time we are issuing an initial call for papers and poster-papers. Even if you are just thinking of presenting a paper please submit the form, and we can follow up with you at a later date.

On the Friday of Conference there will be an Astronomy Outreach Workshop. This is being co-ordinated by Ron Fisher, and again details are available on the RASNZ Webpage, via Conference.

There are many, and various, accommodation options available in Carterton itself and surrounding areas. Some of these are listed on the publicity brochure. The nearest airport is Masterton, but only receives one air service a day, from Auckland. We envisage many people might fly into Wellington, and get the train through to Carterton. The timetable has been printed on the publicity brochure.

Our guest speaker is Associate Professor Wayne Orchiston. Wayne is a past Executive Director of Carter Observatory and is currently Associate Professor in the Centre for Astronomy at James Cook University, Townsville, Queensland. Details of his talks are on the RASNZ Webpage. We also hope to announce a further guest speaker shortly.

The Fellows Lecture for 2012 will be delivered by Dr Edwin Budding. Ed is currently a Research Fellow at Victoria University, and also at the Physics and Astronomy Department at the University of Canterbury. Ed also worked at the Carter Observatory.

-- from a note by Dennis Goodman, Chair, RASNZ Standing Conference Committee

10. Leap Second on June 30

Howard Barnes points out that there will be a leap second on June 30 at 23:59:60 UTC.

11. Do We Need Leap Seconds?

The phrase "clockwork universe" is more than a pithy tribute to the exactitude of physics. For thousands of years, the movement of the heavens (or rather, as was eventually realised, the movement of the Earth within the heavens) served as exactly that -- a clock. It still does. Even the hyper-accurate atomic clocks now used to record the passage of Coordinated Universal Time (UTC), the globe´s official standard, regularly defer to the addition of so-called leap seconds. These are introduced every so often by the time lords of the International Earth Rotation and Reference Systems Service. Their purpose is to match the relentless stream of regular 86,400-second days that pour out of atomic clocks with the slight irregularities that the Earth experiences in its rotation around its axis.

But possibly no longer. Next week, the International Telecommunication Union (ITU) is meeting in Geneva, and one of the items on its agenda is the abolition of the leap second. If the assembled delegates vote in favour, then the next leap second (which will be added one second before midnight on June 30th, causing clocks set to UTC to display 23:59:59 for two seconds instead of one) will be one of the last -- and the answer to the question "what time is it?" will have ceased to have anything to do with the revolutions of the heavens.

Worrying about a few stray seconds may remind some readers of medieval debates about the precise number of angels that could be crammed onto the head of a pin. But, say the abolitionists, time -- even small amounts of it -- does matter. America´s Global Positioning System satellites, for instance, do not add leap seconds to their internal clocks, and are therefore out of step with UTC. Receivers on the ground can correct for that discrepancy. But the satellite-navigation systems being launched by China, Europe and Russia use still other definitions of time, so exceptions to UTC are proliferating. That has led to worries that mismatched time signals could cause navigation problems, since even small errors in a time signal would mean positions being off by tens of metres.

Electronic communication is another area where leap seconds are unwelcome. Days in which it is a second before midnight on two occasions can confuse software that relies on accurately timed messages to function. Workarounds exist, but they cause problems of their own. After some of its computers failed to cope with a leap second in 2005, Google, a search-engine firm, has begun running its computer clocks slowly for a short period before one is due, making the change gradual instead of instantaneous. But, notes Peter Whibberley of the National Physical Laboratory (NPL), Britain´s official measurements lab, that means that while the correction is being applied Google´s watches are out of sync with everybody else´s. And because leap seconds are needed irregularly their insertion cannot be automated, which means that fallible humans must insert them by hand.

Opponents of abolition say such problems are overstated. Engineers are used to dealing with the vagaries of leap seconds, according to Markus Kuhn, a computer scientist at the University of Cambridge. He thinks that a lot of those who worry about leap seconds do not actually have much experience of how things like satnav systems really work. And the switch would not be without problems of its own. Astronomers would be particularly cross: they rely on time having some connection with the movement of the heavens, so that their computers can point their telescopes at the correct patch of sky at a given time every night. A few years down the line, says Dr Kuhn, people may find that automated commercial satellite dishes, which also rely on an astronomical definition of time to spot their quarry, start to fail. Fixing them could mean wading through millions of lines of ancient computer code.

In the longer term, more dramatic effects would appear. Over the decades, centuries and millennia, atomic time would begin to diverge blatantly from solar time because the Earth´s rotation, besides being irregularly variable, is also gradually slowing down [see chart in on-line article]. In about 2,000 years the two measurements would be roughly four hours out of kilter. Eventually, atomic clocks would say it was midday in the middle of the night.

That may seem like a distant worry, but measurements of time can endure for a long time. It has been customary to divide a day into 24 hours for at least 4,000 years, for instance. The final objection is emotional. "Do we really", ask the leap seconds´ defenders, "want to abandon the sun- based reckoning that humans have relied on for their entire recorded history?"

Sadly for the traditionalists, the odds seem stacked against them. An internal ITU poll, conducted last year, found that, of the 16 countries (out of 192) that bothered to reply, 13 were in favour of abolishing leap seconds, whereas only three-thought to be Britain, Canada and China-wanted to keep them. The clockwork universe, then, has had a good run. But its mainspring may be about to break.

-- from The Economist 14 January 2012, p.72-74. See the original article at http://www.economist.com/node/21542717


Leap Second Decision Postponed

A decision on whether to abolish the leap second -- the occasional, extra second added to the world's time -- has been deferred. Experts at the International Telecommunication Union (ITU) were unable to reach a consensus, so moved the matter to a meeting in 2015.

The US argued at the meeting that leap seconds were causing problems for communication and navigation systems. But the UK said that the long-term consequences of losing it were great. An ITU spokesman said that Canada, Japan, Italy, Mexico and France all supported the United States' stance on losing the leap second, while Germany, like the UK, wanted the extra second to stay. More countries though, including Nigeria, Russia and Turkey, wanted further study.

As a result, the ITU decided that more research was needed to consider the broader social implications of losing the leap second before a decision could be taken. The ITU suggested that a study group should investigate the issue, before presenting any proposals at the next World Radio Conference in 2015. It means that for now, the world's time will continue to be linked to the Earth's rotation.

-- from an article by Rebecca Morelle, Science reporter, BBC News, noted by Pam Kilmartin. See the full text at http://www.bbc.co.uk/news/science-environment-16625614

12. Reverend George Burgess?

Anthony Kinder writes: I am currently engaged in compiling as complete a list as possible of all the members of the British Astronomical Association since its foundation in 1890. Included in this is any biographical information (full dates of birth/death, career, etc.) At present I am focusing on the founder members of the BAA and those up to 1911. One of the founder members of the BAA was the Reverend George Burgess FRAS of Manchester. Sometime around the turn of the century he appears to have emigrated to New Zealand, and presumably died there. If any person could provide me with any information about this person I would appreciate it. So far as I am aware he was either a Methodist or Baptist minister (his name does not appear in Crockford's directory of Anglican ministers). Any assistance would be fully acknowledged. Also, may I ask that if any one is or was a member of the BAA could they also provide any information they wish to divulge, this will be kept confidential (for all living respondents), and is used solely for statistical purposes. Sources (e.g. obituaries, newspapers, etc.) would also be appreciated.

Email replies to Anthony Kinder This email address is being protected from spambots. You need JavaScript enabled to view it.

13. White Dwarf Merger Makes Type I Supernova

It has long been accepted that Type Ia supernovae happen when a white dwarf star exceeds a critical mass limit around 1.4 times the mass of the sun. At that mass the pressure in the star's interior is such that the carbon nuclei in the star begin fusing. An explosion then destroys the whole star. White dwarf stars -- the cores of stars originally as big as eight times the sun's mass -- are made mostly of carbon and oxygen.

The question has been where the white dwarf gets the extra mass from. Does it come from material drawn from a nearby companion star of a normal type, or could the explosion result from two white dwarf stars merging?

Evidence favouring the merger scenario has come from a Hubble Space Telescope (HST) study of a Type Ia supernovae remnant in the Large Cloud of Magellan. The remnant is catalogued as SNR 0509-67.5 from its coordinates.

There are no recorded observations of its explosion. However, researchers at the Space Telescope Science Institute have identified light from the supernova that was reflected off of interstellar dust, delaying its arrival at Earth by 400 years. This delay, called a light echo, of the supernova explosion allowed the astronomers to measure the spectral signature of the light from the explosion. From this they were able to prove it was a Type Ia supernova.

The remnant appears as a symmetric shell or bubble, so the geometric centre can be accurately determined. Thus it is an ideal target to search for ex-companions. The young age of the remnant also means that any surviving stars have not moved far from the site of the explosion.

The team failed to find any ex-companion star near the centre of the remnant. This supports the idea that the supernova explosion was caused by a pair of white dwarf stars merging.

"We know that Hubble has the sensitivity necessary to detect the faintest white dwarf remnants that could have caused such explosions," said lead investigator Bradley Schaefer of Louisiana State University. "The logic here is the same as the famous quote from Sherlock Holmes: `when you have eliminated the impossible, whatever remains, however improbable, must be the truth.´"

-- from Louisiana State University via http://www.physorg.com/

14. A Planet for Every Star

An international team has estimated that our galaxy contains a minimum of one planet for every star on average. This means that there is likely to be a minimum of 1,500 planets within just 50 light-years of Earth. A rough estimate from this suggests that there are more than 10 billion terrestrial (Earth-sized) planets across our galaxy.

The results are based on observations taken over six years by the PLANET (Probing Lensing Anomalies NETwork) collaboration. The study concludes that there are far more Earth-sized planets than Jupiter-sized worlds. This is based on calibrating a planetary mass function that shows the number of planets increases for lower mass worlds.

The team used statistics gleaned from a planet search technique called microlensing. If one star passes precisely in front of another star, the gravity of the foreground star bends the light from the background star. This means that the foreground star acts like a giant lens amplifying the light from the background star. A planetary companion around the foreground star can produce additional brightening of the background star. This additional brightening reveals the planet, which is otherwise too faint to be seen by telescopes.

The higher the mass of the "lensing" star, the longer is the duration of the microlensing event. A typical microlensing event due to a star lasts about a month. But the extra brightening due to a planet typically lasts a few hours to a couple of days. Using the microlensing technique, astronomers can determine a planet's mass. This method, however, does not reveal any clues about the world's composition.

Wide-field survey campaigns such as OGLE (Optical Gravitational Lensing Experiment) and MOA (Microlensing Observations in Astrophysics) cover millions of stars every clear night in order to find stellar microlensing events as early as possible. Follow-up collaborations, such as PLANET, monitor selected candidates more frequently, 24 hours a day, using a round-the-world network of telescopes.

Of the approximately 40 microlensing events closely monitored, three showed evidence for exoplanets. Using a statistical analysis, the team found that one in six stars hosts a Jupiter-mass planet. What's more, half of the stars have Neptune-mass planets, and two-thirds of the stars have Earth-mass planets. Therefore, low-mass planets are more abundant than their massive counterparts.

Results from the three main techniques of planet detection -- star wobble, transits and microlensing -- are rapidly converging to a common result: Not only are planets common in the galaxy, but there are more small planets than large ones.

These results are independent from a gravitational-lens survey led by Takahiro Sumi of Osaka University in Japan, which estimates there are hundreds of billions of planets with orbits larger than Saturn's orbit, or are free-floating throughout the galaxy.

The results are published in the January 12 issue of Nature. -- From a European Space Agency/Hubble Space Telescope press release Information Centre via http://www.physorg.com/

15. Asteroid Moa

An asteroid discovered by Tsutomu Seki in 1991 has been named after the Japan/NZ MOA project. The official citation is: (14880) Moa = 1991 CJ1 Discovered 1991 Feb. 7 by T. Seki at Geisei. A giant flightless bird of New Zealand thought to have become extinct by A.D. 1400, MOA is also the acronym of the project Microlensing Observations in Astrophysics which involves New Zealand and Japanese universities.

16. How to Join the RASNZ

A membership application form and details can be found on the RASNZ website http://www.rasnz.org.nz/InfoForm/membform.htm. Please note that the weblink to membership forms is case sensitive. Alternatively please send an email to the membership secretary This email address is being protected from spambots. You need JavaScript enabled to view it. for further information.

The annual subscription rate is $75. For overseas rates please check with the membership secretary, This email address is being protected from spambots. You need JavaScript enabled to view it..

17. Gifford-Eiby Lecture Fund

The RASNZ administers the Gifford-Eiby Memorial Lectureship Fund to assist Affiliated Societies with travel costs of getting a lecturer or instructor to their meetings. Details are in RASNZ By-Laws Section H.

For an application form contact the Executive Secretary This email address is being protected from spambots. You need JavaScript enabled to view it., R O'Keeffe, 662 Onewhero-Tuakau Bridge Road, RD 2, TUAKAU 2697

18. Kingdon-Tomlinson Fund

The RASNZ is responsible for recommending to the trustees of the Kingdon Tomlinson Fund that grants be made for astronomical projects. The grants may be to any person or persons, or organisations, requiring funding for any projects or ventures that promote the progress of astronomy in New Zealand. Full details are set down in the RASNZ By-Laws, Section J.

For an application form contact the RASNZ Executive Secretary, This email address is being protected from spambots. You need JavaScript enabled to view it. R O'Keeffe, 662 Onewhero-Tuakau Bridge Road, RD 2, TUAKAU 2697

Alan Gilmore Phone: 03 680 6000 P.O. Box 57 This email address is being protected from spambots. You need JavaScript enabled to view it. Lake Tekapo 7945 New Zealand