RASNZ Email Newsletter, June 2013
Email Newsletter Number 150
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. The Conference and TTSO72. The Solar System in July
3. Video Occultation Observing Manual
4. Robotic Observatory in the Wairarapa
5. Deep Centaurus A Image
6. Conference Notes - Part 1
7. 2014 Conference at Whakatane
8. Video of the Nearby Universe
9. How Big Stars Form
10. Lightest Exoplanet Imaged So Far
11. Kingdon-Tomlinson Fund
12. Gifford-Eiby Lecture Fund
13. How to Join the RASNZ
1. The Conference and TTSO7
The RASNZ's Conference at Invercargill was a great success. Around 90 attended from Kaitia to Bluff. As well several participants 'crossed the ditch' from as far away as Perth and Alice Springs. Details of the Conference opening and the first papers are in Item 6. Many of the Conference papers will appear in coming issues of Southern Stars.
Our featured guest was Jean-Francois Kaufeler of the European Space Agency (ESA). Jean-Francois has been responsible for the setting up of the launch monitoring station in Southland. The station tracks Ariane rockets taking supplies to the International Space Station. (See a summary of Robin McNeil's talk in Item 6.) Jean-Francois also gave a talk about some of ESA's solar system explorations.
The Conference was followed by the Seventh Trans-Tasman Symposium on Occultations (TTSO7) on the Monday and Tuesday. Among many contributions was the release of a beginner's guide to observing occultations by video. This manual was the result of much work by Jacquie Milner and Graham Blow. Details on obtaining the manual are in Item 3. There was also the introduction of the new Astronomical Digital Video System that combines several functions in one box. Several presenters provided how-to guides of the advanced software for occultation predictions and for video image analysis. It is a tribute to Occultation Section Director Graham Blow that such a range of talented persons have been attracted to this scientific pursuit. Brian Loader proposed a vote of thanks to Graham at the end of the symposium.
For the superb organisation on the ground we have to thank the local organising committee: Phil Burt, Steve Butler, Michael Bailey, Pete Stewart and Bob Evans. The Ascot Park Hotel staff also provided great eats for the coffee breaks and a superb Conference dinner.
The overall supervision was by the Standing Conference Committee: Dennis Goodman, Orlon Peterson, Tim Homes, Pauline & Brian Loader, and Warwick Kissling. Pauline looked after the finances and registrations. Orlon and Warwick arranged the programme. Murray Forbes and Graham Blow assembled the TTSO7 programme.
The 2014 conference is at Whakatane from Friday June 6 to Sunday June 8 with a Variable star symposium on the Monday. See Item 7 for details.
TTSO8 will be Melbourne at Easter 2014 in conjunction with the National Australian Convention of Amateur Astronomers (NACAA). Easter 2014 is April 18-21. Details will be advised later.
2. The Solar System in July
PHASES OF THE MOON (times as shown by GUIDE)
New moon: July 8 at 7.14 pm NZST (07:14 UT) First quarter: July 16 at 3.18 pm NZST (03:18 UT) Full moon: July 23 at 6.16 am NZST (Jul 22, 18:16 UT) Last quarter July 30 at 5.43 am NZST (Jul 29, 17:43 UT)
The Earth is at aphelion, its greatest distance from the Sun for the year, on July 6 at 2 am, when the distance will be 1.0167 AU, 152.1 million km.
THE PLANETS IN July
Saturn is visible all evening throughout July. Venus will gradually get to be more visible to the northwest for a little longer following sunset.
Mercury starts the month as an evening object but difficult to see. Later in the month it will become a morning object, low in the dawn sky and quite close to Jupiter and Mars.
PLANETS IN THE EVENING SKY: SATURN, VENUS and at first MERCURY.
SATURN will remain an easy evening object during July, best viewed early evening, especially later in the month when it will set round about 1 am. The planet will remain in Virgo some 12 degrees to the right of Spica. The two make an obvious pair high to the north in the early part of the evening.
With the north pole of Saturn now tilted towards the Earth at an angle 17°, the rings are readily visible through a small telescope.
The first quarter moon will be about 1 degree from Spica early in the evening of July 16, the following evening the moon will be 4.5 degrees to the upper right of Saturn.
Saturn is stationary on July 4 when its westerly, retrograde motion will come to an end as the faster moving Earth swings away from the outer planet. Saturn will then resume its normal easterly track through the stars, slowly taking it away from Spica.
VENUS will only be visible early evening. It sets two hours after the Sun on the 1st advancing to two and three-quarter hours later on the 31st. Look for the planet soon after sunset to the northwest. On July 1, half an hour after the Sun goes down, the planet will be twelve degrees above the horizon. This will increase to a good twenty degrees by the 31st.
On the 10th of July the 3.4% lit crescent moon will be 9° to the left of Venus and virtually at the same level.
MERCURY will be 13 degrees to the lower left of Venus on July 1 when it will set just over an hour after the Sun. At magnitude 3.1, Mercury will be very difficult to locate in the evening twilight. Over the next few evenings the elongation of Mercury from the Sun will decrease quite rapidly until it is at inferior conjunction with the Sun on the 10th. After conjunction Mercury will move into the morning sky.
JUPITER, MARS and MERCURY in the morning sky.
Jupiter passes Mars towards the end of July when low in the dawn sky. The two are closest on the mornings of July 22 and 23 when the planets will be 49 arc-minutes apart. Mars will then be to the lower left of Jupiter and, at magnitude 1.6, a lot fainter. The previous two mornings the planets will be a degree or more apart with Mars to the left of Jupiter. Their separation will increase again on the 24th and 25th with Mars now almost directly below Jupiter.
Early in July Jupiter will rise a little over 30 minutes before the Sun, making it a difficult object. Mars will rise half an hour or so earlier. By the end of July, Jupiter will rise nearly an hour and three-quarters before the Sun, so it will be easier to see, low to the northeast. Mars will have been left behind, rising about 90 minutes before the Sun.
Mercury is at inferior conjunction on the 9th when it will pass some 4.5 degrees south of the Sun. It then moves into the morning sky to be below Jupiter and Mars. By the end of July it will rise about an hour and a quarter before the Sun, so will remain low and a difficult object in the dawn sky. Mercury will by then have brightened noticeably, reaching magnitude 0.2 by July 31st when it will be at its greatest elongation, 20° west of the Sun.
In the second half of July all three planets will be in Gemini, so forming a fairly tight group. Mars is in Taurus for the first half of the month, moving into Gemini on the 15th.
At the end of July, three-quarters of an hour before sunrise, Jupiter will be 8° up to the northeast. Mars, much fainter at mag 1.6 will be 4° to the lower right of Jupiter. Mercury will be 7° to the right of Mars, slightly lower and brighter at mag 0.2. The star Betelgeuse in Orion, will be nearly 20° above Jupiter and Procyon will be some 24° to Jupiter´s right. Both stars have a magnitude close to 0.5, so will be only slightly fainter than Mercury.
OUTER PLANETS
URANUS will rise at midnight mid July. It will be in Pisces at magnitude 5.8.
NEPTUNE rises more than 3 hours earlier than Uranus, so by 7.45 pm at the end of the month. During July, the planet is in Aquarius with a magnitude 7.8.
BRIGHTER ASTEROIDS:
Both (1) Ceres, magnitude 8.8, and (4) Vesta, magnitude 8.6, start July in Cancer. They are below Venus in the evening sky, so setting shortly after the Sun, making them virtually unobservable. Both are in conjunction with the Sun during August.
Other asteroids brighten to become possible binocular objects during July.
(3) Juno brightens from 9.7 to 9.1 during the month, and (7) Iris from 9.3 to 8.4. Both are in Aquarius and about 15° apart. Early in July they rise mid evening, so are essentially late evening objects. They are at opposition mid August reaching magnitudes 9.0 and 7.9 respectively.
(8) Flora is at opposition on July 20 at magnitude 8.7. It starts the month in Capricornus at magnitude 9.3. Flora moves into Sagittarius on the 11th.
(2) Pallas is at magnitude 9.2 in Orion, so not near opposition.
-- Brian Loader
3. Video Occultation Observing Manual
Graham Blow writes:
The RASNZ Occultation Section is pleased to announce the release of version 1 of Observing Occultations Using Video: A Beginner's Guide. You can download the Guide from here:
http://occultations.org.nz/videotime/manual.htm
Although written with observers in Australia and New Zealand especially in mind, we hope that observers elsewhere will still find its contents to be informative and useful.
The editors are looking for feedback on the content and presentation of the Guide. Does it cover all the questions you may want to ask? Is it laid out clearly enough? Please send any comments to:
Jacquie Milner: milnerjacquie@gmail.com with a copy to Graham Blow: Graham@occultations.org.nz
We'd also like to remind you that the website of the RASNZ Occultation Section has changed with immediate effect to: http://www.occultations.org.nz/ Please update your bookmarks accordingly.
4. Robotic Observatory in the Wairarapa
Terry Galuszka wrote to the nzastronomers Yahoo! group:
About a year ago I established a group for running outreach education programmes based around astronomy, target audience being primary and secondary school students. It followed on from being asked by Victoria University to assist with the transit of Venus forum in Tologa Bay. Well, we're progressing, have council support, a trust being established and offers for support (professional services and funding) coming in.
Last week, the local paper got wind of it. Here's the link to the times- age http://www.times-age.co.nz/news/masterton-first-in-online-stargazing/1900955/
5. Deep Centaurus A Image
Rolf Olsen posted on nzastronomers links to a stunning image of Centaurus (NGC 5128) taken over 43 nights in Feb-May this year. The total exposure time was 120 hours with a 10-inch (25-cm) f/5 Newtonian reflector in Auckland. The image is a composite from exposures through LRGB filters taken with a QSI 683wsg camera and Lodestar guider.
Rolf believes that the image is the deepest view ever obtained of Centaurus A. Also that it is likely also the deepest image ever taken with amateur equipment, showing stars as faint as magnitude 25.45. He spent around 40 hours and analysing processing the data, with the goal of presenting this majestic Southern galaxy as it has never been seen before - with all the main features showing in one single image, in order to truly get a grasp of what this intriguing object is all about.
The link to the high resolution image (~4MB)is http://www.rolfolsenastrophotography.com/Astrophotography/Centaurus-A-Extreme-Deep-Field/29643205_8ZwvgW#!i=2536914799&k=mNgSprP&lb=1&s=O
From there are links to other details about the image and its contents.
6. Conference Notes - Part 1
On Friday evening, May 24, around 90 RASNZ members and others gathered at the Ascot Park Hotel for the opening of the Conference.
Phil Burt, President of the Southland Astronomical Society, the host organisation, welcomed attendees. Gordon Hudson, RASNZ President congratulated the Conference Organising Committee on the assembly of a great programme. Gordon noted that this was the 93rd year of the RASNZ´s existence. Council had just held its 514th meeting.
In her welcome, Frana Cardno, Mayor of the Southland District Council, recalled how she used to enjoy looking at the stars from the family´s yacht on Lake Te Anau. Regional astronomical connections include Astronomer´s Point in Dusky Sound, named by Captain Cook in 1773. Bluff Hill was the site of the first auroral radar station in the country. It is remembered in the naming of the current radar station after Bob Unwin. (Bob´s son Martin recalled those days in a talk on Sunday.) Stewart Island is magnetically as far south as civilized places get, outside Antarctica. Hence its Maori name Rakiura: land of glowing skies.
Bob Evans led off the presentations with his Fellows presentation with his memories of the development of amateur astronomy in New Zealand. After a youthful close encounter with the Timaru Adamski Flying Saucer Group Bob discovered real astronomy and the Canterbury Astronomical Society. There he helped with building the first dome at the Joyce Observatory at West Melton. He was introduced to occultation observing by Ron Cross, and to variable star observing by Frank Bateson. In 1969 Bob visited Auckland on a teachers´ refresher course for a week, taking Clive Rowe´s first photoelectric photometer so it could be tried out on the new 50-cm Cassegrain telescope. This led to an extensive and continuing programme of photometry at Auckland Observatory. Bob moved to Ashburton College where he found an old With- Browning 10-inch Newtonian in an old dome. It originally belonged to Henry Skey of Dunedin. Bob was instrumental in having the telescope refurbished and re-housed under a run-off roof at a new site. The Ashburton Astronomical Society still use it. Bob ground an 8-inch mirror but never got it aluminized. On an English mounting it was used to take photos of the moon but little else. Satellite tracking became an amateur activity in the late 1960s with several 5-inch Apogee telescopes being established. Christchurch has two: one at Christ´s College, run by Nick Heath; another at West Melton. Systematic recording of aurora was begun in the 1930s by Murray Geddes. Ivan Thomsen continued the work at the Carter Observatory till 1958 when the auroral radar station started. Dennis Goodman revived the Auroral Section of the RASNZ in the 1970s. Bob took it over and widened its remit to solar observing as well. Bob continues to run the Aurora and Solar Section of the RASNZ. In all it has been an interesting five decades. Bob´s granddaughter is being encouraged to follow in his footprints. With Bob´s help she is already contributing to the Globe at Night surveys.
Saturday morning began with Robin McNeill, CEO of Venture Southland, talking of local space projects. The most recent is a communications station for the European Space Agency (ESA). ESA send Automated Transfer Vehicles - essentially 10-tonne trucks launched from French Guiana on Ariane 5 rockets - to supply the International Space Station. The stage 2 burn happens 400 km up over Australia and NZ. Now it has added Monitoring of the vehicle is carried out by ESA technicians. The ESA-NZ Arrangement (one step down from a Treaty) includes scholarships for Southland school pupils. Astronauts and engineers also talk to schools, broadening pupils´ horizons. A tangible result has been a doubling of the number of pupils doing Year 13 physics. Invercargill is 46 degrees south in geographical latitude but 54 degrees south in magnetic measurement. This is because the south magnetic pole in near the Australian edge of Antarctica. Thus Southland is a prime region for observing aurora. The Bluff Hill auroral station was established in 1958 with a visual and photographic station starting at Lauder, near Alexandra, in 1960. The trans-Tasman TIGER auroral radar array started in 2005, with much of the hardware made locally. Robin would like to set up a radio telescope in Southland, perhaps to link to the Auckland University of Technology´s dish at Warkworth. However, there isn´t funding for research at this time.
Tom Richards outlined the work that Variable Stars South was doing encouraging eclipsing binary observation and analysis. The section has about 50 members. Their subs provide an income to fund research. Members cover a range of activities ranging from CCD observations and brightness measurement of the target stars to analysis of the resulting light curves. There is now a wealth of software available for this. See, for example, www.binarymaker.com. Tom´s paper on this topic will appear in the June issue of `Southern Stars´.
Graeme Kershaw told of the demise and potential resurrection of the historic Townsend Telescope. The telescope was housed under a dome at the top of a tower at Christchurch´s Arts Centre, the old University of Canterbury site. The tower was weakened in the 2010 September 4 earthquake. There were discussions on removing the telescope - with minimal personnel, just in case - till 2011 February 22 when the CBD- centred after-shock shattered the tower. Photos taken immediately after the tower´s collapse show the copper dome, looking spherical, sitting on top of the masonry pile. However, an Urban Search and Rescue digger drove all over it looking for bodies. Weeks later Arts Centre staff delivered to UC all the parts of the telescope that they had found in a meticulous search of the rubble. The telescope tube was mostly flattened but, miraculously, the 150-year-old Cooke 5-inch objective lens survived. Also the finder telescope´s objective. Having been involved with refurbishment of the Townsend back in the late 1970s, Graeme is keen to repeat the exercise. The guesstimated cost is $60k-80k. Donations toward this project will be gratefully received. Contact Sharlene Mullen <sharlene.mullen@canterbury.ac.nz> for donation details. Where will the telescope be housed? Possibly in UC´s new Science Complex.
John Talbot showed that careful photometry of Jovian satellite eclipses reveal much about a torus of sulphur atoms around Jupiter in the orbit of Io. During 2012 the sun and us were seeing the orbit plane of the Galilean satellites nearly edge on. Thus satellites were passing through each other´s shadows and occulting each other. Observers measuring these events noticed that the occulted moons often faded markedly long before they were occulted. Analysis showed that these fadings fitted with the moon being observed through the optically thick end regions of the torus of sulphur around Io´s orbit. The torus is much larger than Io, extending out to 6-8 times Io´s radius. Some observations hint that it could be asymmetrical: as much as 31 radii on one side and 10 radii on the other. Additionally, the precise photometry shows small-amplitude sinusoidal variations in brightness. These are confirmed by separate observers, so can´t be an instrumental effect. They may be related to the `zebra pattern´ found in some radio emissions from Jupiter. John´s observations were made with a home-made 25-cm f/4 `occultascope´ usually stopped down to 50mm. A video camera system did the recording. Other Jupiter moons were used as brightness check stars. A new series of these events will occur in 2014.
Steve Butler encouraged everyone to get out under the night sky and measure its brightness. For US$135 + p&p you can buy a Sky Quality Meter. See http://unihedron.com/projects/sqm-l/ for details. After a short integration an SQM tells you the sky brightness in magnitudes per square second of arc. A really dark sky looks like it has on magnitude 21.5 star in each such square. Steve made a series of measurements from the centre of Invercargill, where 20% of upward-directed floodlighting hits its target, to 15 km out of town. The CBD the sky was at 14 mag per sq.arcsec. This dropped to 20.5 just 4 km from the town centre. Malcolm Locke is doing a similar survey around Christchurch. Grant Christie reported that the Auckland astronomical Society has an application in to purchase several SQMs. These will be used to identify dark sky sites around Auckland with the aim of getting them protected. Steve also noted that the colour of the light pollution is important. Blue is particularly bad for humans. The Correlated Colour Temperature (CCT) describes the dominant colour. The moon´s CCT is around 4000 degrees Kelvin. Warm-white LEDs have a hotter CCT. One can get an estimate of the CCT by using a Spectrum Viewer for US$9.
John Hearnshaw announced that a second edition of his history of spectroscopy is just about ready for publication. Cambridge University Press expect to have it out in late 2014. The first book, in 1986, covered the history up to 1970 when 202,000 papers related to stellar spectroscopy had been published. In the interval 1971-2000 some 453,000 new papers appeared. Hence it has taken him 41/2 years to complete the update begun in 2009. The new book will be of larger format in two columns. The 30 years have seen extraordinary advances. Echelle spectrographs have become common, CCDs have replaced photography, spectral classifications have been revised, brown dwarfs have been discovered, extremely old and metal-poor Population III stars have been found, far-UV spectroscopy has been done by satellites. John found some interesting stories during his research. Enjar Hertzsprung was an amateur astronomer when he plotted up what became known as the Hertzsprung-Russell diagram in 1908. He showed it to a nearby professor who was very impressed and offered him a job. Sometime later Henry Norris Russell arrived at the same diagram by a different analysis. However, the first note published about the diagram was by Hans Rosenberg, two years after Hertzsprung plotted it. So the `HR´ has two meanings. In 1905 William Campbell and Herber Curtis proposed looking for planets by the radial velocity (RV) method. This was achieved in 1995. In 1952 Otto Struve suggested using the RV method to search for massive planets orbiting close to their host stars: `hot Jupiters´. The planet found in 1995 was a half-Jupiter mass orbiting its star in four days. And in 1924 Albert Einstein predicted gravitational red-shift. After many erroneous attempts it was finally measured correctly with the Hubble Space Telescope.
-- From the Newsletter Editor's notes. Not to be taken as a true and correct record of what the presenters actually said. Watch for their articles in 'Southern Stars'. More next month (I hope...) -- Ed.
7. 2014 Conference at Whakatane
Those of you who were at the close of the Invercargill conference will have seen the presentation featuring the 2014 conference to be hosted by the Whakatane Astronomical Society at, naturally, Whakatane.
It will be in early June, dates are Friday June 6 to Sunday June 8 with a Variable Star South symposium on the Monday. The venue for the conference will be the Whakatane War Memorial Centre. The venue for the VSS symposium is the nearby Eastbay REAP building.
Plans for the conference are moving ahead. The Local Organising Committee is planning a pre-conference tour on the Friday afternoon which will include a visit to the Whakatane Society's fine observatory.
It's not too early to be planning your presentation for the conference. We would be particularly interested to hear details of observations being made by yourself or your local society.
-- Brian Loader, Chair, RASNZ Standing Conference Committee.
8. Video of the Nearby Universe
An international team of researchers, including University of Hawaii at Manoa astronomer Brent Tully, has mapped the motions of structures of the nearby universe in greater detail than ever before. The maps are presented as a video, which provides a dynamic three-dimensional representation of the universe through the use of rotation, panning, and zooming. The video was announced last week at the conference "Cosmic Flows: Observations and Simulations" in Marseille, France, that honoured the career and 70th birthday of Tully.
The Cosmic Flows project has mapped visible and dark matter densities around our Milky Way galaxy up to a distance of 300 million light-years.
The team includes Helene Courtois, associate professor at the University of Lyon, France, and associate researcher at the Institute for Astronomy (IfA), University of Hawaii (UH) at Manoa, USA; Daniel Pomarede, Institute of Research on Fundamental Laws of the universe, CEA/Saclay, France; Brent Tully, IfA, UH Manoa; and Yehuda Hoffman, Racah Institute of Physics, University of Jerusalem, Israel.
The large-scale structure of the universe is a complex web of clusters, filaments, and voids. Large voids -- relatively empty spaces -- are bounded by filaments that form superclusters of galaxies, the largest structures in the universe. Our Milky Way galaxy lies in a supercluster of 100,000 galaxies.
Just as the movement of tectonic plates reveals the properties of Earth's interior, the movements of the galaxies reveal information about the main constituents of the universe: dark energy and dark matter. Dark matter is unseen matter whose presence can be deduced only by its effect on the motions of galaxies and stars because it does not give off or reflect light. Dark energy is the mysterious force that is causing the expansion of the universe to accelerate.
The video captures with precision not only the distribution of visible matter concentrated in galaxies, but also the invisible components, the voids and the dark matter. Dark matter constitutes 80 percent of the total matter of our universe and is the main cause of the motions of galaxies with respect to each other. This precision 3-D cartography of all matter (luminous and dark) is a substantial advance.
The correspondence between wells of dark matter and the positions of galaxies (luminous matter) is clearly established, providing a confirmation of the standard cosmological model. Through zooms and displacements of the viewing position, this video follows structures in three dimensions and helps the viewer grasp relations between features on different scales, while retaining a sense of orientation.
The scientific community now has a better representation of the moving distribution of galaxies around us and a valuable tool for future research.
See the video at http://irfu.cea.fr/cosmography
-- A University of Hawaii press release forwarded by Karen Pollard.
The video is most impressive and very informative. However, it starts slowly and progresses slowly over 17 minutes. If nothing seems to happen at first then just be patient. -- Ed.
9. How Big Stars Form
Stars form from accumulations of gas and dust in space. Denser clumps of gas and dust collapse under their own gravity. The squeezed gas heats up. If the mass is big enough then the temperature at the centre becomes sufficient for thermonuclear processes to start. This heat finds its way to the surface of the mass. Thus we have a star.
A long-standing problem with massive stars is that the radiation from the star should stop further material falling on it. Nevertheless massive stars are found. How does the infalling material overcome the repelling radiation and the 'stellar wind' from the hot massive star?
Part of the answer has been found in a study of the star-forming cloud W3. It is a giant molecular cloud containing an enormous stellar nursery, some 6,200 light-years away in the Perseus Arm of our Milky Way Galaxy. The region has been imaged at long infra-red wavelengths by the European Space Agency's Herschel space observatory. The composite image referenced below was made from images at 70, 160 microns and 250 microns.
Infra-red observations of W3 show that in the very dense regions, there appears to be a continuous process by which the raw material is moved around. Under the influence of clusters of young massive protostars it is compressed and confined.
Through their strong radiation and powerful winds, populations of young high-mass stars may well be able to build and maintain localized clumps of material from which they can continue to feed during their earliest and most chaotic years, despite their incredible energy output.
For text & Images see; http://www.esa.int/Our_Activities/Space_Science/Herschel/Hunting_high-mass_stars_with_Herschel
-- from a European Space Agency press release forwarded by Karen Pollard.
10. Lightest Exoplanet Imaged So Far
A team of astronomers using the European Southern Observatory's (ESO's) Very Large Telescope has imaged a faint object moving near a bright star. With an estimated mass of four to five times that of Jupiter (1300-1600 times Earth's mass), the object would be the least massive planet to be directly observed outside the solar system. The discovery is an important contribution to our understanding of the formation and evolution of planetary systems.
Although nearly a thousand exoplanets have been detected indirectly -- mostly using the radial velocity or transit methods -- and many more candidates await confirmation, only a dozen exoplanets have been directly imaged (http://en.wikipedia.org/wiki/List_of_extrasolar _planets_directly_imaged).
Nine years after ESO's Very Large Telescope captured the first image of an exoplanet, the planetary companion to the brown dwarf 2M1207 (http://www.eso.org/public/news/eso0428), the same team has caught on camera what is probably the lightest of these objects so far.
In the new observations, the likely planet appears as a faint but clear dot close to the star HD 95086. A later observation also showed that it was slowly moving with the star across the sky. This suggests that the object, which has been designated HD 95086 b, is in orbit around the star. Its brightness indicates that it has a mass of only four to five times that of Jupiter.
The team used NACO, the adaptive optics instrument mounted on one of the 8.2-meter Unit Telescopes of ESO's Very Large Telescope (VLT). This instrument allows astronomers to remove most of the blurring effects of the atmosphere and obtain very sharp images. The observations were made using infrared light and a technique called differential imaging, which improves the contrast between the planet and dazzling host star.
The newly discovered planet orbits the young star HD 95086 at a distance of around 56 times the distance from the Earth to the Sun, twice the Sun- Neptune distance. The star itself is a little more massive than the Sun and is surrounded by a debris disc. These properties allowed astronomers to identify it as an ideal candidate to harbour young massive planets. The whole system lies some 300 light-years away from us.
The youth of this star, just 10 to 17 million years, leads astronomers to believe that this new planet probably formed within the gaseous and dusty disc that surrounds the star. "Its current location raises questions about its formation process. It either grew by assembling the rocks that form the solid core and then slowly accumulated gas from the environment to form the heavy atmosphere, or started forming from a gaseous clump that arose from gravitational instabilities in the disc." explains Anne-Marie Lagrange, a team member. "Interactions between the planet and the disc itself or with other planets may have also moved the planet from where it was born."
Another team member, Gaël Chauvin, concludes, "The brightness of the star gives HD 95086 b an estimated surface temperature of about 700 degrees Celsius. This is cool enough for water vapour and possibly methane to exist in its atmosphere. It will be a great object to study with the forthcoming SPHERE instrument on the VLT. Maybe it can also reveal inner planets in the system -- if they exist."
SPHERE is a second-generation adaptive-optics instrument that will be installed on the VLT in late 2013. For details see http://www.eso.org/sci/facilities/develop/instruments/sphere.html)
-- from a European Southern Observatory press release forwarded by Karen Pollard.
11. 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, secretary@rasnz.org.nz R O'Keeffe, 662 Onewhero-Tuakau Bridge Rd, RD 2, TUAKAU 2697
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 secretary@rasnz.org.nz, R O'Keeffe, 662 Onewhero-Tuakau Bridge Rd, RD 2, TUAKAU 2697
13. 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 members@rasnz.org.nz for further information.
The annual subscription rate is $75, not including the Yearbook. For overseas rates please check with the membership secretary, member@rasnz.org.nz.
Newsletter editor:
Alan Gilmore Phone: 03 680 6000 P.O. Box 57 Email: alan.gilmore@canterbury.ac.nz Lake Tekapo 7945 New Zealand