Sorry for the lateness on this, been busy! Anyway, in late November, Dr Rob Matson picked up a moving object in SWAN images, and Terry Lovejoy provided a ground-based confirmation of it. Originally listed in NEOCP as SWAN12B, it was later designated C/2012 V4. Michael Mattiazzo of Castlemaine, Vic, first suggested a link between this comet and the long-lost D/1827 M1 (Pons-Gambart). The first tentative orbit based on a 62 year period suggested that two apparitions had been missed but in the latest MPEC a new orbit has been proposed that makes this the first return of the comet since 1827, apparently a much better fit. The MPEC went on to say:
"
At the present time, the solution presented here is believed to be correct, as the fit of the bulk of the 1827 observations (known to be grossly inaccurate by modern standards) is far better than earlier attempts with shorter orbital periods. There is a slight systematic trend in the current residuals, which may be related to observation weighting. Continued observation is clearly desirable."
Bit more work to be done in this fascinating story! The comet has been temporarily given the C prefix while they work on the period, and there is no name pending more certainty in the link to Pons-Gambart.
Anyway, last Sunday I got a clear break and set up camera & telescope and had a short but intense viewing/photographic session. I was taking 1 min subs of the field as the sky darkened and the comet sank lower in the west, interspersed with dashes to the eyepiece while ICNR was doing its stuff! I could see the comet clearly (4.5" f8 reflector at 43x) but because I never got properly dark adapted it looked very small and faint. The image I got is the first attached, the comet showing a lovely green.
Monday night I scrapped the camera and decided to get a good observation of the comet:
C/2012 V4, 2012 Dec 3.455 UT; m1= 9.5; Dia= 2'; DC= 5; 11.4cm f8 refl (43x) [Rob Kaufman, Bright, Vic, Australia].
Small coma moderately condensed, no tail visible; bright star-like inner coma visible in brief glimpses in poor seeing; low elevation in west, sky brightness. Ref= NOMAD1 data in ViZier; Method= M.
Then work, life & clouds intervened and I'm on the road again sans telescope. But it was pretty exciting seeing what had probably not been seen since 1827!
The comet is more than likely not viewable now from southern areas as it has moved into daylight. It will return briefly to our skies later on but much, much dimmer.
http://www.minorplanetcenter.net/mpec/K12/K12X14.html
http://scully.cfa.harvard.edu/cgi-bi...d=c&o=CK12V040
C/2012 V4 is also currently moving through the STEREO Behind HI2 field and showing a growing tail. Here's a link to a little animation I put together from data from 27 Nov, no tail showing then:
http://i727.photobucket.com/albums/w...7animation.gif
Attached is an image from HI2B from 4 Nov, showing the long tail.
Cheers -
