Topic: Early November Astronomy Bulletin

[Clive]

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.