[Sorry I've been absent for so long - lots of stuff happening this year.]
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The SOCIETY for POPULAR ASTRONOMY
Electronic News Bulletin No. 364 2013 November 10
Here is the latest round-up of news from the Society for
Popular
Astronomy. The SPA is Britain's liveliest astronomical society, with members all over the world. We accept subscription payments online at our secure site and can take credit and debit cards. You can join or renew via a secure server or just see how much we have to offer by visiting http://www.popastro.com/ ASTEROID 2013 TV135 NASA
The
then-undiscovered asteroid 2013 TV135 made a close approach to
the Earth on Sept. 16, when it came within about 6.7 million km. The asteroid is estimated to be about 400 m across and its orbit carries it out to about three quarters of the distance to Jupiter. It was discovered on 2013 Oct. 8 by astronomers working at the Crimean Astrophysical Observatory in Ukraine. It is one of more than 10,000 near-Earth objects that have been discovered. With only a month of observations for an orbital period of almost four years, its orbit is still poorly determined, but it looks as if the asteroid could be back in our neighbourhood in 2032. The object will be in the accessible part of the sky in the coming months, and the refinement of the orbit is likely to show that there is no risk of Earth impact in 2032. EXOPLANET TALLY ABOVE 1,000 BBC News
The
number of observed exoplanets now stands informally at 1,010,
bolstered by 11 new finds from the UK's Wide-Angle Search for Planets (WASP). The Kepler space telescope, which discovered many such planets in recent years, broke down earlier this year, but it left a list of more than 3,500 other candidates that have not yet been followed up. MOST DISTANT KNOWN GALAXY DISCOVERED University of California
Astronomers
have discovered the most distant galaxy yet found. The
galaxy is seen as it was 'just' 700 million years after the Big Bang, when the Universe was only about 5 per cent of its current age of 13.8 billion years. The team identified a very distant galaxy candidate in optical and infrared images taken by the Hubble telescope. Follow-up observations, made in Hawaii by the Keck telescope with its new multi-object spectrograph 'MOSFIRE', allowed its redshift to be determined at 7.5 -- the Lyman-alpha emission line of hydrogen, whose wavelength 'at rest' is far down in the ultraviolet, was observed shifted into the red part of the spectrum. The observations showed that the distant galaxy, prosaically named z8-GND-5296, is forming stars extremely rapidly -- producing each year stars totalling about 300 times the mass of our Sun, about 100 times the rate of star formation in the Milky Way. COULD A MILKY WAY SUPERNOVA BE VISIBLE IN NEXT 50 YEARS? Ohio State University
Astronomers
have estimated the odds that, some time during the next 50
years, a supernova occurring in our home galaxy will be visible to us. They think it very likely that such a supernova will be visible to telescopes operating in the infrared, but the chance that the spectacle would be visible to the naked eye in the nighttime sky is only 20 per cent or less. We see supernovae go off in other galaxies every few days, but we could learn more about them if we can catch one in our Galaxy and study it with all available instruments, including new types such as detectors of neutrinos and gravitational waves. Astronomers' contingency plans hope to take advantage of the fact that supernovae issue neutrinos immediately after the explosion starts, but don't brighten in infrared or visible light until minutes, hours, or even days later. So, with luck, neutrino detectors such as Super- Kamiokande in Japan would sound the alert the moment they detect neutrinos, and indicate the direction the particles were coming from. Then infrared detectors could target the location almost immediately, catching the supernova before the brightening begins. Gravitational- wave observatories might do the same. Not all neutrinos, however, come from supernovae -- some come from nuclear reactors, the Earth's atmosphere or the Sun -- but there have been suggestions as to how ones of supernova origin might be distinguished.
For
those of us who might hope to see a Milky Way supernova with our
own eyes, however, the chances are low and depend on our latitude -- the southern hemisphere is favoured because most of the Galaxy is seen from there. The last time it happened was in 1604, when Johannes Kepler observed one some 20,000 light years away in the constellation Ophiuchus. So it would have been unproductive for anyone to have sat on the edge of his chair for the last 400 years hoping to see the next one! INDIA'S MARS-ORBITER MISSION The Planetary Society
The
Indian Space Research Organization has told how its 'Polar
Satellite Launch Vehicle' has placed its Mars-bound spacecraft into a highly elliptical parking orbit with a perigee of 248 km and an apogee of 23,000 km. Over an interval of about a month, six orbital manoeuvres will gradually increase the distance of the apogee, and finally a seventh one will put the craft on a path that will take it to Mars. The cruise to Mars will take about ten months. Its orbit round Mars will likewise be highly elliptical. The spacecraft carries a small payload of five instruments with a total mass of 15 kilograms. The scientific goals of the mission have not been spelt out in any detail: "Exploration of Mars surface features, morphology, mineralogy, and Martian atmosphere by indigenous scientific instruments." ["Indigenous" means 'developed in India'.] The instruments consist of a Lyman-alpha photometer, methane sensor, 'Exospheric Neutral Composition Analyser', colour camera and thermal-infrared imaging spectrometer.
But
what this mission is really about is the development of India's
capability in space -- the technological objectives are the main drivers. ISRO states three objectives: 1. Design and realisation of a Mars orbiter able to survive and perform Earth-bound manoeuvres, cruise phase of 300 days, Mars orbit insertion/capture, and on-orbit phase around Mars. 2. Deep-space communication, navigation, mission planning and management. 3. Incorporate autonomous features to handle contingency situations.
Each
of the three is a substantial challenge, and achieving any one
of them will demonstrate new capability for India. BBC CONFIRMS THAT 'THE SKY AT NIGHT' WILL CONTINUE
The
BBC has announced that the programme 'The Sky At Night' will
continue next year. From February, it will be in a new monthly half-hour slot on BBC4, with repeats on BBC2. Kim Shillinglaw, Head of Commissioning for BBC Science and Natural History, says: "Sir Patrick Moore inspired generations of astronomers and I hope that, alongside the BBC's other astronomy content such as BBC2's Stargazing Live, The Sky at Night will enthuse further generations about the wonder of the night sky." The Sky at Night was first broadcast on 1957 April 24 and continued to be presented by Sir Patrick Moore until his death in 2012, making it the longest-running programme with the same presenter in television history. Since Moore's death, the series has been fronted by various stand-in presenters. Bulletin compiled by Clive Down
(c)
2013 the Society for Popular Astronomy
The
Society for Popular Astronomy has been helping beginners in
amateur astronomy -- and more experienced observers -- for 60 years. If you are not a member then you may be missing something. Membership rates are extremely reasonable, starting at just £18 a year in the UK. You will receive our bright bi-monthly magazine Popular Astronomy, help and advice in pursuing your hobby, the chance to hear top astronomers at our regular meetings, and other benefits. You can join online right now with a credit card or debit card at our lively website: www.popastro.com
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