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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. Professor John Mackie 1910-2012
2. Astrocamp at Foxton Beach, August 17-19
3. Higgs Boson Found
4. The Solar System in August
5. Mars Science Laboratory Arrives August 6
6. Lowell Amateur Research Initiative
7. Filters for Visual Observing
8. Third International Starlight Conference Report
9. NEO-Finder Privately Funded?
10. Dim Glob Discovered
11. How to Join the RASNZ
12. Gifford-Eiby Lecture Fund
13. Kingdon-Tomlinson Fund

1. Professor John Mackie 1910-2012

The society's oldest member, Fellow and former President passed away on 7 July 2012 peacefully at his home surrounded by family. John joined the Society in 1963 and served on Council during the period 1965-73 including a term as President. In 1969 he was elected as a Fellow in recognition of his "fundamental contributions to practical surveying astronomy". An article describing Johns 100th birthday appeared in the September 2010 issue of Southern Stars. We extend our condolences to John's family at this time of loss.

-- Glen Rowe

2. Astrocamp at Foxton Beach, August 17-19

The Horowhenua Astronomical Society, in conjunction with the Phoenix Astronomical Society, is holding the Winter Astro-Camp in the Horowhenua/Manawatu from 17th to 19th August. It is at the Foxton Bible Camp, Foxton Beach.

The overall theme of the weekend will be the winter Milky Way and the Clouds of Magellan. The camp is situated in a very dark site so these wondrous areas of the night sky will be easily visible and riding high in the sky.

The weekend will include: hydrogen-alpha solar viewing and photography; a hands-on astrophotography workshop in a quiet, comfortable lounge; night-time observing and live video astronomy, through a variety of telescopes (feel free to bring your own telescopes - the more the merrier!); a telescope trail; a display of 3D images - the Universe as you´ve never seen it before! There will also be a programme of interesting talks on a variety of topics throughout the day and, in the event of bad weather, during the evening. There is also a pool table and table tennis as well as a playground with numerous outdoor activities.

Astro-Camp Fee: People over 18 years $20.00. Under 18 free. On Site Accommodation: Cabins: $15 per night per person over 5 years old; $3 per night for preschoolers. Day visitors: $3 per day (in addition to the $20.00 Astro-Camp fee). You must bring your own pillow slips and bedding. A large fully equipped kitchen is available. The camp is hired on a `do-it- yourself´ basis. Groceries can be bought locally.

Book online at: www.horoastronomy.org.nz. For queries contact the HASI Secretary, Tina Hills, at: This email address is being protected from spambots. You need JavaScript enabled to view it..

-- From information sent by Simon Hills

3. Higgs Boson Found

Historical events recede in importance with every passing decade. Crises, political and financial, can be seen for the blips on the path of progress that they usually are. Even the horrors of war acquire a patina of unreality. The laws of physics, though, are eternal and universal. Elucidating them is one of the triumphs of mankind. And this month has seen just such a triumphant elucidation.

On July 4th physicists working in Geneva at CERN, the world´s biggest particle-physics laboratory, announced that they had found the Higgs boson. Broadly, particle physics is to the universe what DNA is to life: the hidden principle underlying so much else. Like the uncovering of DNA´s structure by Francis Crick and James Watson in 1953, the discovery of the Higgs makes sense of what would otherwise be incomprehensible. Its significance is massive. Literally. Without the Higgs there would be no mass. And without mass, there would be no stars, no planets and no atoms. And certainly no human beings. Indeed, there would be no history. Massless particles are doomed by Einstein´s theory of relativity to travel at the speed of light. That means, for them, that the past, the present and the future are the same thing.

Such power to affect the whole universe has led some to dub the Higgs "the God particle". That, it is not. It does not explain creation itself. But it is nevertheless the most fundamental discovery in physics for decades.

Unlike the structure of DNA, which came as a surprise, the Higgs is a long-expected guest. It was predicted in 1964 by Peter Higgs, a British physicist who was trying to fix a niggle in quantum theory, and independently, in various guises, by five other researchers. And if the Higgs - or something similar - did not exist, then a lot of what physicists think they know about the universe would be wrong. Physics has two working models of reality. One is Einstein´s general relativity, which deals with space, time and gravity. This is an elegant assembly of interlocking equations that poured out of a single mind a century ago. The other, known as the Standard Model, deals with everything else more messily.

The Standard Model, a product of many minds, incorporates the three fundamental forces that are not gravity (electromagnetism, and the strong and weak nuclear forces), and also a menagerie of apparently indivisible particles: quarks, of which protons and neutrons, and thus atomic nuclei, are made; electrons that orbit those nuclei; and more rarefied beasts such as muons and neutrinos. Without the Higgs, the maths which holds this edifice together would disintegrate.

Finding the Higgs, though, made looking for needles in haystacks seem simple. The discovery eventually came about using the Large Hadron Collider (LHC), a machine at CERN that sends bunches of protons round a ring 27km in circumference, in opposite directions, at close to the speed of light, so that they collide head on. The faster the protons are moving, the more energy they have. When they collide, this energy is converted into other particles (Einstein´s E=mc2), which then decay into yet more particles. What these decay particles are depends on what was created in the original collision, but unfortunately there is no unique pattern that shouts "Higgs!" The search, therefore, has been for small deviations from what would be seen if there were no Higgs. That is one reason it took so long.

Another was that no one knew how much the Higgs would weigh, and therefore how fast the protons needed to be travelling to make it. Finding the Higgs was thus a question of looking at lots of different energy levels, and ruling each out in turn until the seekers found what they were looking for.

For physicists, the Higgs is merely the LHC´s aperitif. They hope the machine will now produce other particles - ones that the Standard Model does not predict, and which might account for some strange stuff called "dark matter". Astronomers know dark matter abounds in the universe, but cannot yet explain it. Both theory and observation suggest that "normal" matter (the atom-making particles described by the Standard Model) is only about 4% of the total stuff of creation. Almost three-quarters of the universe is something completely obscure, dubbed "dark energy". The rest, 22% or so, is matter of some sort, but a sort that can be detected only from its gravity. It forms a giant lattice that permeates space and controls the position of galaxies made of visible matter. It also stops those galaxies spinning themselves apart. Physicists hope that it is the product of one of the post-Standard Model theories they have dreamed up while waiting for the Higgs. Now, they will be able to find out.

For non-physicists, the importance of finding the Higgs belongs to the realm of understanding rather than utility. It adds to the sum of human knowledge - but it may never change lives as DNA or relativity have. Within 40 years, Einstein´s theories paved the way for the Manhattan Project and the scourge of nuclear weapons. The deciphering of DNA has led directly to many of the benefits of modern medicine and agriculture. The last really useful subatomic particle to be discovered, though, was the neutron in 1932. Particles found subsequently are too hard to make, and too short-lived to be useful.

This helps explain why, even at this moment of triumph, particle physics is a fragile endeavour. Gone are the days when physicists, having given politicians the atom bomb, strode confidently around the corridors of power. Today they are supplicants in a world where money is tight. The LHC, sustained by a consortium that was originally European but is now global, cost about $10 billion to build.

That is still a relatively small amount, though, to pay for knowing how things really work, and no form of science reaches deeper into reality than particle physics. As J.B.S. Haldane, a polymathic British scientist, once put it, the universe may be not only queerer than we suppose, but queerer than we can suppose. Yet given the chance, particle physicists will give it a run for its money.

See http://www.economist.com/node/21558254. -- From The Economist 7 July 2012.

4. The Solar System in August

The usual notes on the visibility of the Planets for August 2012 are on the RASNZ web site: http://www.rasnz.org.nz/SolarSys/Aug_12.htm. Notes for September 2012 will be on line in a few days.

The planets in august

Mars and Saturn remain visible in the early evening with Mars passing between Saturn and Spica mid month. At their closest the two planets will be less than 3° apart.

Venus and Jupiter remain easy objects in the morning sky. Jupiter will steadily rise earlier and get higher in the early dawn sky. Venus will rise at about the same time all month, but closer to the time of sunrise as that gets earlier.

Mercury also rises before the Sun but only an hour earlier at its greatest, making the planet virtually unobservable.

Mars and saturn plus spica in the evening sky

As seen about 8 pm at the beginning of August, Mars will be some 8° below Spica, with Saturn 4.5° to the lower right of the star. During August Mars, moving to the east through the stars, will pass between Saturn and Spica. It ends the month above the pair. Mars will set only 20 minutes earlier at the end of August than at the beginning. By contrast, Saturn sets more than 100 minutes earlier. So it will seem that it is Saturn, with Spica, that moves down past Mars.

When the three are closest in mid August they will be setting at about 11pm. So best viewing will be fairly early in the evening. On the 14th the three will be almost in line with Spica about 1.75° to the left of Mars, and Saturn about 2.75° to the right of Mars. Saturn will be slightly brighter than Mars and Spica. The following evening the two planets will be slightly closer, but by then Mars will be above the line joining Spica and Saturn.

Saturn and Spica themselves will be closest on the 3rd and 4th, just under 4.5° apart. The distance of Saturn from Spica will slowly increase during the rest of August but will not exceed 4.5° until the 16th and remain less than 5° by the 31st.

The 25% lit moon will join the three on the evening of August 22. Early that evening it will be 2°, 4 diameters, to the left of Mars and some 5° above Saturn and Spica.

Planets in the morning sky

Venus and JUPITER move further apart in the morning sky during August.

Venus starts August in Taurus but its easterly movement through the stars takes it into Orion on the 5th where it crosses the most northerly lobe of the constellation, 12° below Betelgeuse. By the 13th Venus will have moved into Gemini where it will be 3.5° below the second magnitude star Alhena, gamma Gem, on the morning of the 18th. On the last morning of the month Venus will be between Procyon in Canis Minor and Pollux in Gemini. While Procyon should be quite easy to see an hour before sunrise, some 14° to the upper right of Venus, Pollux will be very low and to Venus' left.

At the beginning of August, Venus will rise about 3 hours before the Sun, dropping to some two-and-a-half hours earlier by the end of the month. The difference is almost entirely due to the Sun beginning to rise earlier, the actual time at which Venus rises changing little during the month.

The moon passes close to Venus in August. On the morning of the 14th in New Zealand, the 15% lit crescent moon will be just over 1°, twice the moon's diameter, to the lower left of Venus. An occultation of the planet by the moon occurs as seen from parts of the northern hemisphere. It will take place before sunrise for Japan, northeast China and much of Siberia. The occultation will be a day time event for the most easterly parts of Siberia and almost the whole of North America.

Jupiter, unlike Venus, rises steadily earlier in the morning as August advances. In the North Island of NZ it rises about 3.30 am early in the month and 2 am by the end. It will rise a little later further south. By 6 am it will be at a reasonable altitude, about half way between north and northeast early in the month and closer to north by the end.

The planet will be in Taurus a few degree lower than Aldebaran and about 15° to the right of the Pleiades, moving a little further from the cluster during the month. On the morning of the 12th, the 31% lit moon will be a degree to the left of Jupiter. As for Venus, there will be an occultation of Jupiter by the moon. It will be visible from Indonesia and some of the northeast coast region of Australia during the hours of darkness. In daylight the path of the occultation swings in an arc over the mid Pacific with Hawaii at its northern edge.

Mercury is also a morning object during August. At the most it will rise about an hour before the Sun mid month. On the morning of the 16th it will be less than 4° up half an hour before sunrise. The moon, a very thin crescent 4% lit will be a similar distance above and slightly left of Mercury. The planet will be at magnitude 0.1. Even so, with the Sun only 6° below the horizon, Mercury is likely to be difficult to see.


Uranus will be moving slowly to the west in a corner of Cetus jutting into Pisces. With a magnitude between 5.8 and 5.7 it will readily be visible in binoculars. By the end of August it will rise shortly after 8pm. At midnight on the 31st it will be to the northeast, 40° above the horizon in the north New Zealand, 30° in the south.

Neptune is at opposition on August 24, so by then will rise close to the time of sunset and set near sunrise. The planet, magnitude 7.8, will be in Aquarius moving slowly to the west about 12° from the two brightest stars of the constellation.

Brighter asteroids:

(1) Ceres and (4) Vesta are both morning sky objects in Taurus in the vicinity of Jupiter and Aldebaran.

At the beginning of August, Ceres will be at magnitude 9.1 and 4.6° to the right of Jupiter, forming a near equilateral triangle with the planet and Aldebaran. The star will be at the top of the triangle. Ceres and Jupiter are both moving to the east through the stars and will remain about level all month. Their separation will increase to over 9° by the end of August. By then Ceres will have brightened slightly to magnitude 8.9

Vesta will be 4.5° to the upper right of Jupiter, with the two at their closest on the morning of August 12. The same morning the moon is 1° from Jupiter. Vesta will overtake Jupiter during the month but remain a little higher. Early in August the asteroid will pass very close to Aldebaran with the two 11 arc-minutes apart on the morning of the 6th. Vesta, at magnitude 8.3 will be to the lower left of Aldebaran. It should be visible using binoculars while the sky is still dark.

(2) Pallas brightens from magnitude 9.5 to 8.8 during August. It starts the month in Pisces, but moves into Cetus on the 8th. It will be within a few degrees of Uranus.

(11) Parthenope brightens to magnitude 9.5 mid August and to 9.0 by the end of the month. The asteroid will be in Aquarius.

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

-- Brian Loader

5. Mars Science Laboratory Arrives August 6

On August 6, a capsule is going to come screaming out of the Martian sky, then -- all going well -- break its fall by popping a parachute and engaging rocket thrusters. After that, the 'sky crane' inside the capsule will activate to lower the subcompact-car-sized Curiosity rover on tethers, suspending it beneath the rest of the craft until the whole assembly descends onto a carefully chosen patch of ground at the northwestern end of the 150- km-diameter Gale crater. NASA's Mars Science Laboratory (MSL) will have landed.

The goal of MSL is to assess whether Mars was ever a habitable environment. Every potential landing site had to have some evidence that water was involved in the formation of the landscape and in the rock deposited there. A site also must have the potential to preserve biomarkers, the telltale indicators that organic material was once present.

Gale crater was selected as it has a mysterious mound 4500 metres high, informally called Mount Sharp. It also has clays and sulphates in it, indications of water. How did that mound get there? Did volcanic ash and dust blow in and contribute to the buildup of the mound? How and why did the area around it erode away? When water was there, where did it come from? To look for answers, the rover will drive at least partway up the mound, examining layers as it goes.

For more see http://www.nasa.gov/mars and http://mars.jpl.nasa.gov/msl/

-- from NASA press releases forwarded by Karen Pollard.

6. Lowell Amateur Research Initiative

Lowell Observatory is proud to announce the Lowell Amateur Research Initiative (LARI). This program seeks to pair the ever-growing and technically sophisticated amateur astronomy community in exciting research projects with Lowell astronomers.

A passionate researcher, Percival Lowell always sought to communicate new ideas and the joy of astronomy research to the public. In that same spirit, LARI brings together professional and amateur astronomers in a way that affords interested amateurs an opportunity to participate in cutting-edge research and potentially make significant contributions to science. Amateurs can help Lowell astronomers in their work and help create dedicated research teams. LARI will expand Lowell Observatory's education and public outreach missions, and promote greater awareness of astronomy and related sciences.

Currently, Lowell astronomers are conducting several projects that would benefit from the participation of amateur astronomers. These projects span a broad range of technical skills and knowledge from taking very deep images of galaxies to monitoring small stars for transient events to data mining.

Visit http://www.lowell.edu/LARI_welcome.php to find out more and to create your LARI account. After getting a sense of your skills and interests, we will do our best to match you with the appropriate researcher and project.

-- A Lowell Observatory press release forwarded by Graham Blow.

7. Filters for Visual Observing

A question to nzastronomers "Does anyone use filters for visual observing of nebulae with a big dob?" got several helpful answers. The answers in no particular order:

Depends on what you are looking at. I must say I was impressed with Eta Carinae viewed thru an O-III filter. Best bet, see if someone nearby can lend you a filter. I often switch in an OIII or CLS when trying to discern details in visual. It obviously goes darker but quite often dust lanes and dark areas stand out more.

In my view, the best all-round filter is a broad-band (deep sky) nebula filter. Then comes a UHC filter which has higher contrast but will cut down on overall intensity of the object. Finally the OIII filter is really only good on objects emitting that frequency band, mostly planetary nebulae, but will enhance some other emission nebulae giving you a very dark background with reduction of much starlight.

I started with 1.25" Lumicon filters, then went to the Orion 2" filters (which don't have the narrow passbands found in Lumicon and other more costly ones). But, if you want to see actual performance, have a look at the following webpage. http://www.astrosurf.com/buil/filters/curves.htm You will see that some filters (e.g. Astronomik H alpha) are not centred on the wavelength required to be passed or there is variation within the same product from filter to filter. He (Cristian Buil) doesn't test all the popular filters and maybe you can find other spectral comparisons. I prefer to use this kind of comparison instead of the qualitative ones that seem to abound on the web.

I once borrowed a UHC filter about 20 years ago, and used it to look at the Tarantula Neb. I wasn't all that impressed with the result until I stepped back from the telescope and discovered that while was observing, a large chunk of cumulus had inserted itself in the way. Without the filter I wouldn't have seen anything at all. When I used it again on the Tarantula in excellent conditions I was greatly impressed. It felt like the nebula had leaped down the tube and shaken me until my teeth rattled. The difference between filter and no filter was incredible. The skylight filter was a bit of an improvement on no filter; but the UHC - Wow! It can appear at first that the stars are dulled a bit, but that isn't surprising since the filter is designed to increase the contrast of emission nebulae. I also have a Swan band filter for comets, but again it isn't great for comet-hunting, but is great for distinguishing between predominantly gassy, and dusty comets.

-- Answers from Brent Russell, Larry Field, Kerry Koppert and Rod Austin

8. Third International Starlight Conference Report

The Third International Starlight Conference took place at the Godley Hotel, Lake Tekapo, on June 10-13. It was hosted by Canterbury University, by RASNZ and by UNESCO's Starlight Initiative. It brought together 64 participants from a very diverse range of backgrounds to discuss issues of light pollution, starlight reserves, astro-tourism and stargazing, Maori astronomy and the aesthetics of a dark sky. The participants included astronomers, tourism operators, conservationists, lighting engineers, experts in Maori astronomy, lawyers, educators and those simply enthralled by the beauty of the night sky. With such a multi-disciplinary meeting, no-one was an expert in everything and we all learnt a lot about the multi-faceted and fast growing Dark Sky Reserve movement around the world.

Coinciding with the conference was the announcement from Bob Parks, Executive Director of the International Dark-Sky Association (headquarters in Tucson, Arizona), that the Aoraki Mackenzie region had been successful in gaining the status of the world's third and largest International Dark Sky Reserve, following the application by the Aoraki Mackenzie Working Party (chair Margaret Austin), a committee established by the Mackenzie Tourism and Development Trust under the aegis of the Mackenzie District Council. The 181- page application document was prepared by the Working Party last summer after several years of careful planning and preparation.

It was good to be able to announce our success at the opening reception of the Starlight Conference and be declared a reserve with gold tier status, the first gold tier reserve in the world. A significant boost for Mackenzie and Aoraki/Mt Cook tourism and stargazing can be expected as a result.

The conference was opened by Sir Tumu te Heuheu, paramount chief of Ngati Tuwharetoa in Turangi, who was former chair of the World Heritage Committee of UNESCO. We enjoyed a buffet dinner for 90 people and a kapa haka group from Twizel School on the Sunday evening. Then followed 37 very interesting talks over the next three days; Monday evening was a stunningly clear dark night on Mt John when all the participants enjoyed stargazing activities. We also had screenings of two recent documentaries on dark sky and environmental protection, one (Sky Whisperers) produced in Christchurch, the other (the City Dark) from New York. The latter was open to the public, so we had a good crowd from the local community.

On the Tuesday evening the participants had a sumptuous banquet at the Godley Hotel with one of the most erudite and witty speeches you could ever hear from David Round, the well-known environmental lawyer in Canterbury University's School of Law. We concluded the Starlight Conference with a Public Forum, where six internationally known overseas experts answered questions from the public.

After the Conference, 15 of the participants went to the Hermitage at Mt Cook and participated in a closed workshop to discuss World Heritage issues in relation to astronomy over the next two days. We made significant progress towards the concept of inscribing significant sites of astronomical significance onto the World Heritage list.

I am grateful to the many people who supported and sponsored the Starlight Conference, not least the Department of Physics and Astronomy of Canterbury University, and also many other prominent individuals and organizations throughout New Zealand (a full list of sponsors is on the conference website at www.starlight2012.org). Many thanks too to Graeme Plank who served as audio-visual technician at the conference; to Rosalie Reilly who attended to a wide range of secretarial tasks before the meeting, and Beth Leal-Eager from Learning Resources who co-ordinated the technical side of the web pages.

-- John Hearnshaw

9. NEO-Finder Privately Funded?

Asteroid strikes are the ultimate in low-probability, high-impact events. In 1908 a space rock a few tens of metres across disintegrated over Siberia. The explosion flattened more than 2,000 square kilometres (800 square miles) of forest. The power of the blast was between ten and 15 megatonnes, about that of the most powerful nuclear weapons built during the cold war. That the meteorite in question blew up over Siberia instead of, say, Paris or Beijing was pure luck.

Happily, politicians are aware of the risk. In 1992 America´s Congress suggested that NASA, that country´s space agency, begin surveying asteroids whose orbits might make them a threat. At the moment, NASA is aware of 1,320 "potentially hazardous asteroids", defined as those whose orbits bring them near Earth and which are more than 150 metres across, but it reckons this is only around a quarter of the total. A space telescope called NEOCam (Near Earth Object Camera), designed to look for such rocks, is on the drawing board.

But NASA may soon have help - or competition - from elsewhere. On June 28th the B612 Foundation, an American charity named after the asteroid home of a character in "The Little Prince", a French children´s book, announced that it wanted to launch an asteroid-spotting space telescope of its own. Dubbed Sentinel, this telescope is to be paid for by private donations, built by a team of engineers including veterans of other space- telescopes flown by NASA and, if all goes according to plan, launched by SpaceX, a private rocketry firm, in 2018.

The B612 Foundation is not a newcomer to the space business. It was started in 2002. And one of its founders, Rusty Schweickart, was an Apollo astronaut. As with other private space enterprises, many of its donors made their money in the computing industry. Its original purpose was to invent ways of deflecting asteroids that might be on a collision course with Earth, working on the assumption that the problem of spotting them in the first place could be handled by NASA and other, ground-based astronomers.

But budget cuts have hit NASA´s science missions hard. NEOCam is not certain to fly, and the foundation worries that, although NASA has already catalogued most of the biggest, civilisation-ending asteroids, thousands of smaller rocks, of similar dimensions to the one that exploded over Siberia, remain undetected. If one were to hit the wrong part of the planet it would cause a catastrophe. Hence the shift in focus from deflection to discovery.

Sentinel´s mission will be broadly similar to NEOCam´s. Both telescopes will have 50cm mirrors. Both will scan the sky in the infra-red spectrum, where dark but comparatively warm asteroids should show up brightly against the cold of deep space. Both will inhabit orbits between Earth and the sun, in order to get the best possible vantage point. The foundation´s ambition is to produce an asteroid map that records 90% of near-Earth objects that are more than 140 metres across, and half of those bigger than 50 metres. Armed with data on their orbits and velocities, astronomers should be able to calculate which pose a threat over the coming century or so.

Although that should take care of most of the truly fearsome rocks (and provide a bonanza for scientists who study asteroids), Sentinel´s catalogue will not be comprehensive. Even relatively small impacts can do a lot of damage. Barringer Crater in Arizona is 1.2km in diameter. It was carved by something similar in size to Siberia´s devastator - but denser, hence the crater.

Worrying about this sort of thing may seem esoteric. For a long time, asteroid impacts were treated as a bit of a joke. The giggling subsided somewhat in 1994, when astronomers had a front-row seat as the fragments of a comet called Shoemaker-Levy 9 smashed into Jupiter. The energy released by this collision was hundreds of times greater than the combined explosive power of every nuclear weapon on Earth. The Earth-sized dent in the Jovian atmosphere persisted for months.

And that is not the only worrying close encounter of late. On June 17th 2002, for instance, astronomers spotted an 80-metre rock that missed Earth by an astronomical hair´s breadth, passing well inside the orbit of the Moon. The trouble was, they only noticed it three days after its point of closest approach. Sentinel, if it flies, should make that sort of thing less likely. And it won´t cost taxpayers a penny.

-- The Economist 7 July 2012 p.69

10. Dim Glob Discovered

A team of American, Canadian and Chilean astronomers have stumbled onto a remarkably faint cluster of stars orbiting the Milky Way that puts out as much light as only 120 sun-like stars. The tiny cluster, called Muñoz 1, was discovered near a dwarf galaxy in a survey of satellites around the Milky Way using the Canada-France-Hawaii Telescope (CFHT) and confirmed using the Keck II telescope, both of which are on Mauna Kea, Hawaii.

"What's neat about this is it's the dimmest globular cluster ever found," said Ricardo Muñoz, an astronomer at the University of Chile and the discoverer of the cluster. A globular cluster is a spherical group of stars bound to each other by gravity so that they orbit around a galaxy as a unit.

Muñoz noticed the tiny cluster near the Ursa Minor dwarf galaxy. Most globular clusters have in the range of 100,000 stars. Muñoz 1 has something like 500 stars. That puts Muñoz 1 head-to-head with the Segue 3 globular cluster -- also orbiting the Milky Way -- as the dimmest troupe of old stars ever found.

Muñoz 1's discovery was the result of a survey done with the CFHT MegaCam imager in 2009 and 2010. It was then confirmed by spectroscopic study using a spectrograph on the Keck II telescope. Spectra showed that Muñoz 1 and the Ursa Minor dwarf galaxy had quite different velocities so were not related. Analysis of the brightness and colours of the stars in Muñoz 1 and the Ursa Minor galaxy also suggests that the tiny cluster is about 100,000 light years nearer to us than the dwarf galaxy.

As for how Muñoz 1 came to be so dim, a likely scenario is that it has gradually lost stars over the eons. It's also possible it was stripped of stars by passing through the Milky Way. But the direction of the cluster's movement is not yet known, so it's not known whether it has passed through the Milky Way.

Perhaps the most intriguing aspect of the discovery is the possibility that there are many more such globular clusters in the Galactic halo. After all, the CFHT survey covered only 40 square degrees of sky out of 40,000 square degrees in the entire sky.

"To truly understand its nature, we will need to measure its mass," added Muñoz. To do that, astronomers would need to measure the velocities of individual stars in the cluster and see how they move with relation to each other. That, in turn, reveals the overall mass of the cluster. A lot of mass would suggest there is a lot of dark matter holding the cluster together. That might qualify the cluster as the smallest, darkest galaxy ever discovered. Right now the Segue 1 dwarf galaxy holds that record.

A copy of the preprint of the paper is available at http://www.cfht.hawaii.edu/en/news/Munoz1/munoz12.pdf

-- From a Canada-France-Hawaii Telescope press release forwarded by Karen Pollard.

11. 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, not including the Yearbook. For overseas rates please check with the membership secretary, This email address is being protected from spambots. You need JavaScript enabled to view it..

12. 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 Rd, RD 2, TUAKAU 2697

13. 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 Rd, 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


Newsletter editor:

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