sábado, 25 de octubre de 2008

Comet 29P/Schwassmann-Wachmann and Spiral Galaxy IC 2269

Periodic comet Schwassmann-Wachmann (29P) is a funny body of unpredictable behaviour. It frequently shows rather sudden increases in brightness which are followed by an expansive wave of material, only to fade away rather abruptly afterwards.

A very detailed graph of the nuclear activity of comet 29P can be seen at Comets_Obs database. This shows the magnitude of the nucleus using a 10"x10" box.

http://www.astrosurf.com/cometas-obs/29P/multi.htm

A new refinement to this curve has just been added by Julio Castellano at Comets_Obs to try to better understand what is going on in the "core": it consists of an adjustment to the 10X10 magnitude data to account for the absolute distance of the comet .

http://astrosurf.com/cometas-obs/_MHDC/29P/

The most recent outburst of activity ocurred on September 15 (IAUC 8978) and was reported (another first!) by acomplished observer Juan Antonio Henríquez Santana at station MPC J51. His images reveal the comet a two-full magnitudes brighter than previously observed.

I imaged the comet on October 26 early in the morning when the comet was at a decent height above the Eastern horizon. The coma has grown in size to 3.5' and is now more transparent as the material has started to dissipate.

sábado, 4 de octubre de 2008

Low excentricity comet C2008 T1 Boattini

On the night of October 1, a supicious object was posted on the NEO confirmation page. When I started imaging it, there were only few observations by the original discoverer (Andrea Boattini at Mt. Lemmon) and some other observatories. Local conditions were only marginally good (no Moon but mediocre seeing) and the body was crossing a star-populated field, so the only images I could take barely allowed to pinpoint is astrometric coordinates. The real cometary nature of this object was then confirmed by several other observers.
According to preliminary calculations by Brian G. Marsden, C2008 T1 is a very short-period comet that experienced a very close encounter with Jupiter in 2003.