Comet P/2008 WZ96 - ASO Discovers Comet Status of Poorly Observed Asteroid

Using the 0.5m astrographic telescope on Petit Jean Mountain (H45), P. Clay Sherrod reported a possible comet with a poorly observed and little known asteroid that had been found in November 2008. This object - 2008 WZ96 - had even been removed from the NEO and unusual lists of asteroids which demands frequent observations by astrometrists and other asteroid observers.

Sent to the T3 Group - a group of non-professional and professional astronomers dedicated to detecting cometary objects from reported asteroids - Sherrod suspected 2008 WZ96 early in January of being a comet, rather than an asteroid, as noted in this letter sent to the group on Jan. 21:

"I would like to request observers to take a serious look at asteroid (?)
2008 WZ96, presently at magnitude 18.6 or so; I have been monitoring this
object since late December 2008 and have frequently suspected some slight
nebulosity around a very difficult-to-resolve core. The past week I have
obtained images that suggest a strong coma with little or no condensation on
two dates and have reported such to MPC with (surprise....) no response.

The nebulous appearance of this object was so evident on Jan 19 UT, that an
exact centroid could not be determined.

What is very odd about this, is that there are no observations being posted
on this object whatsoever (NEO-MPEC daily reports); on some dates the object
does appear more stellar but at this time, the last few observations are
revealing a strong suggestion of nebulosity, albeit a very small object.

Any input would be appreciated.

Clay
_____
Dr. P. Clay Sherrod
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West
http://www.arksky.org/"

Observations by observers were initially inconclusive due to the fact that this object was getting very low in SW skies right after dusk and atmospheric turbulence precluded convincing images that the object was indeed nebulous, and not stellar, as an asteroid would appear.

On Jan. 27, Luca Buzzi of Schiaparelli Observatory, Italy, provided qualitative images that showed the object to be 30% more extended than very faint stars of similar magnitude nearby.

"Dear all,
after Clay's alert, tonight I've taken some images of 2008 WZ96 with our 0.60-m reflector
+ CCD.
I enclose to you the stack on the asteroid and the stack at zero motion.
FWHM of the target seems 30% larger than stars nearby, but the seeing tonight was not
good, so for me this is not enough to be sure to see cometary appearance. However, the
object is worth a look with other telescopes.
Of course I will try again in the next days.
Thanks again to Clay for pointing this out.

Best regards,
Luca Buzzi
# 204.."

On January 30, the Central Bureau of Astronomical Telegrams issued the bulletin that the comet was indeed just that and issued the confirmations from observers, mostly of the T3 Group.

The comet is presently very low in SW skies and about 18th magnitude; the Minor Planet Center MPEC was issued today, Jan. 30:
http://www.cfa.harvard.edu/mpec/K09/K09B73.html

The comet is now known officially as P/2008 WZ96 LINEAR and will not bear the Sherrod name since it was a previously discovered object. Nonetheless, we are excited to have been active in alerting the astronomical community to the true nature of this object, which had been overlooked until the Jan. 21 alert was posted by ASO.

Much appreciation to all T3 and other observers, and Dr. Brian Marsden of Harvard-Smithsonian, for their follow-up to the early ASO suspicions.

Dr. Clay

PHOTO BELOW courtesy of Luca Buzzi, MPC 204, showing his indication of possible cometary nature of P/2008 WZ96 [CLICK IMAGE TO ENLARGE]