Quote:
Originally Posted by robgreaves
Had a good time - some pretty decent skies, and brought home some nice images from my TOA150 rig.
Had fun early hours of Sunday morning with a fair bit of excitement on my 'potential' comet discovery. Rob McNaught assisted in interrogating the MPC databases, as did Monte Wilson in follow-up observations. After a bit of head-scratching, it turned out to already have been discovered not so long ago, so maybe next time 
Regards,
Rob |
Hi Rob,
For me, this event was the highlight of the star party and it showcased
the incredible capability that comes from the convergence of several key
technologies along with the ability of professional astronomers being able
to co-operate with amateurs.
A small group of us were assembled in the Meeting Hall where Monte Wilson
had his laptop computer interfaced to his Takahashi robotic mount equipped
with SBIG camera. The laptop was also interfaced to a LCD projector so we
could all watch what was happening on the 'big screen'.
Monte was preparing for the asteroid occultation due later that night and those
assembled were assisting him in identifying the correct star in the field.
I was sitting next to Monte when the walkie-talkie call from Rob Greaves came
through. Rob was imaging on the upper field at the house on his own
well-equipped rig and reported a possible comet candidate he had spotted
on the edge of the FOV near the Antennae interacting galaxies.
Calling out the RA and Dec, Monte's rig slewed into action and within a few minutes
we were scrutinizing the image on the big screen. Sure enough, there was
a nebulous object at the co-ordinates Rob had reported and though there were
several known galaxies in the region, none corresponded to this fuzzy object.
A few minutes later, Monte performed a second image acquisition and performed
a blink test comparison. Lo and behold, it was moving.
Monte had his NextG handset interfaced to the laptop and the first port of
call was the Minor Planet Center in Harvard where we used the search engine
to try and determine if there were any known minor planets or comets near these
co-ordinates at this time. The MPC server reported none. It was now 3am but Rob's
candidate object was giving us all a shot equivalent to a dozen espressos.
Could this be a new comet? By now, Rob had joined us in the meeting hall and
we agreed some consultation from an expert would now be prudent. By luck, the
guest speaker that same day was none other than Rob McNaught, the man that
has discovered more comets as an individual in the entire history of of mankind.
Rob Greave's wife, Jessica, who has acute night vision, managed to track down
Rob McNaught on the observing field. Rob was attempting to capture the
asteroid occultation event on a video camera. When Rob McNaught became free,
Rob Greaves explained to him that he had found an object that might be a comet,
that it had been imaged on two scopes and that a blink comparison showed
movement and that a preliminary MPC search drew a blank. I mischievously
asked Rob McNaught, with regards these comets, would he happen to know anything
about the topic? He answered something to the effect that he had some dealing with
them professionally before.
Rob McNaught came to the meeting hall and started to ask a series of questions.
For example, does the object move when the scope is panned, which might
indicate an internal reflection? As the object had been imaged on two different
scopes and when panned did not moved, we were confident it was not an
internal reflection. Had we entered our latitude and longitude into the MPC
search engine to account for parallax if the object was close, or had we used the
default geocentric co-ordinates? When we explained we had hurriedly used the
defaults, Rob requested we revisit the MPC search engine. He typed in the
code for Siding Springs (close enough) and widened the search, explaining that
the orbital elements could be providing positions that might be as much as a couple
of degrees out. The wider search kept the MPC server busy for about a minute
and then a series of candidate objects appeared on the big screen.
"That will be it", Rob McNaught said, pointing out C/2007 W1 (Boattini), a 12th
magnitude comet discovered by Rob's northern hemisphere counterpart around
about last November.
See
http://cfa-www.harvard.edu/iau/Ephem...ts/2007W1.html
We were disappointed and I imagine especially Rob Greaves. Who would not be?
However, the chase had been an exciting one and watching these amazing
technologies in action made one appreciate how far things have come. Only
a few years ago, if one had seen such an object at Wiruna, it would have most
likely be seen visually rather than through imaging and would probably then
have had to await returning to Sydney to check on the Internet rather than be
able to access the Internet from a location that has no fixed telephone
wiring or mains power. Even the LCD projector and the ability for several
people to view what was happening and make comments and suggestions
enabled new levels of co-operation between amateurs - the whole time
sitting indoors in relative comfort with cups of coffee. It had a "Mission
Control" feel about it. Then what chance having Rob McNaught on the field
and his experienced hand being able to direct us?
The next day Rob McNaught explained the chance of someone discovering a new
comet is increased if they have discovered a new comet before. This at first
might seem paradoxical, but it was clear that the experience of finding and
verifying a new comet then assists one through going through the motions of
finding and verifying the next.
With that in mind, there are possibly a few tips in the above commentary
when it comes to verification. Pan the mount to check it is not an internal reflection.
Acquire at least a couple of images and do a blink comparison or visually
compare with the target field. Get a second verified observation from an
independent observer. Try and determine the astrometric co-ordinates
as best as possible by multiple images with an accurate recording of the time.
This will help practitioners to determine its orbital elements. Use the
information and search capabilities of the MPC including entering
your latitude and longitude and widening the search to at least 300 arc minutes
from the nominal co-ordinates you have estimated. I am sure experienced comet
discovers would have plenty of additional advice. However, I would like
to thank Rob Greaves, Rob McNaught and Monte for making the early hours
of Sunday morning so exciting whilst we hunted this down. It was also
a nice opportunity to meet Rob Greaves and Jessica for the first time.
Keep looking up!
Best Regards
Gary Kopff
Mt. Kuring-Gai
Thanks to all for the hospitality - Geoff's, Deane & Amanda,(thanks Deeno for giving Lyn all the good advice on the Argo!!!!!),Michaels,Scott and Rod once again for the views through 
