SPA Comet
News, January 2003
Bright comets seem to be coming hot on the heels of
each other at the moment. I was proven
dramatically wrong that there were unlikely to be any more amateur visual
discoveries, when Tetsuo Kudo and Shigehisa Fujikawa found a bright comet in
mid December. It had in fact been
visible in SWAN imagery, but the satellite team were running well behind with
posting the images on the Internet and no-one spotted it until after the event. This was followed up with a CCD discovery by
Charles Juels and Paulo Holvorcem on the first night that they tested a wide
field imaging system.
Sebastian Hoenig's comet took an unexpected nosedive
in brightness at the end of September.
All the evidence points to the comet having been discovered a few days
after it commenced a major outburst, which resulted in the disintegration of
the entire comet. The other comet of
the summer, 2002 O6, was named SWAN, rather contrary to the previous convention
on naming such comets after the satellite that discovered them. It was quite a nice object, but low down in
the twilight for most of the time. It
too faded quite rapidly and it may also have disintegrated.
Comet NEAT (2002 V1) wasn't really expected to do
very well, because when it was discovered it seemed to be quite a faint object
that was unlikely to survive perihelion.
It came into visual range in November and as the observations came in,
it became clear that the comet was actually brightening quite rapidly. This rate of brightening has continued and
the comet is now a binocular object and should be an easy naked eye object by
the end of January. For February we
will have to wait and see. Simple
extrapolation of the light curve suggests a peak of perhaps -10, but this would
be amazing to say the least. The comet
could equally disintegrate, perhaps leaving behind a tail like the Cheshire
cat's grin.
It is a conveniently placed evening object and it
should be possible to observe it until mid February. If it really does become a brilliant object then it may be
possible to follow it in daylight for another ten days. It will pass through the SOHO C3 coronagraph
field between February 17 and 20. A
bright comet offers many opportunities for amateurs. It should be very easy to photograph and may provide some
splendid views for drawing and sketching.
There may be interesting phenomena such as jets, hoods or fountains
close to the nucleus, which often require high magnification to observe. Simple spectroscopes may show metallic
emission lines. If there are few
comparison stars visible, it is possible to reduce the apparent magnitude of
the comet by observing through reversed binoculars with one eye.
Comet Kudo-Fujikawa (2002 X5) was discovered by
Japanese amateur Tetsuo Kudo on December 13.83 with 20x120 binoculars and by
his compatriot Shigehisa Fujikawa who independently found it in a 16cm
reflector. Fujikawa is a well-known
discoverer of comets and this is his 6th comet. Although reported as 9th
magnitude at discovery, some observers quickly put it as bright as 7th
magnitude. It isn't brightening very
rapidly, but it had reached mag 5.5 and developed a short tail as it closed in
on the Sun in mid January. It will soon
be too close to the Sun for visual observation, but you may see it passing
through the SOHO C3 coronagraph field of view between January 26 and 31. It then heads south (I am too and will be in
Antarctica from mid February to the end of March), but if it maintains its
present light curve we should be able to pick it up again in mid March. By then it will be a binocular object of
around 8th magnitude and it will fade fairly quickly. There is some evidence that it too may have
been discovered in outburst, as the light curve suggests that it could have
been discovered a month earlier.
Comet Juels-Holvorcem (2002 Y1) is another object
that wasn't originally expected to get within binocular range, but it too seems
to be brightening quite rapidly. If it
really is doing so, then it may become a binocular object in February, visible
in the evening sky, and reach 5th magnitude in early April, though
by then it will have become a morning object.
SPA members have been busy observing all these
objects. Mike Feist has been making
regular observations of 2002 X5 and has already glimpsed 2002 V1. Stephen Getliffe has been able to observe some of the fainter
comets over the past few months and Cliff Meredith has been imaging both the
bright comets. I had an amazing run at
the beginning of January, making observations on every day for the first 12 days. This made up for December, which was a
memorably cloudy month.
Springer have just published a new book on
'Observing Comets' and have generously made some copies available for
competition prizes. The book is written
by SPA Member Nick James and Gerald North and covers all aspects of comet
observing. The SPA competition is to
submit an illustration or drawing of a bright comet. This could be a fictional drawing, an imaginary view of an
historic comet, a scenic photograph or a painting and can be on paper or sent
as an image. Comet 2002 V1 (NEAT) may
provide a real example to draw or photograph.
The submission should be sent by post to myself at 11 City Road,
Cambridge CB1 1DP or in electronic form by email. Please give your membership number when submitting. The winner will receive a copy of the book,
and their submission, along with those of the runners up, will be published in
Popular Astronomy. The closing date is
April 16.
A meeting that should be of interest to all comet
observers is a Pro-Am meeting on meteors, meteorites and comets that is being
held at the Open University at Milton Keynes on May 10. There is an exciting range of speakers and
the day will culminate in the presentation of the George Alcock Memorial
Lecture by Brian Marsden. Competition
prizes will be presented at the meeting to any winners that come along.
For more information on current comets, the latest
updates on comets NEAT, Kudo-Fujikawa and Juels-Holvorcem and more details of
the competition and meeting see my web page at
http://www.ast.cam.ac.uk/~jds Updates
on the progress of all the comets will be posted in the SPA ENBs.
Jonathan Shanklin