Possible Detection of a Short Tail Behind Comet 17/P Holmes

The recent brightening of comet Holmes has
spurred a frenzy of observations both by amateurs and professionals
astronomers alike. All these observations reveal a tailless round
yellowish fuzzball in the constellation Perseus. Near infrared images
of comet P/17 Holmes, obtained with the 1.6m Ritchey-Chretien telescope
at Mont Megantic Observatory (Qc, Canada), indicate a small tail-like
feature next to the comet’s head.

The images were obtained by graduate student Sandie Bouchard and
night assistant Bernard Malenfant on the morning of October 26, using
SIMON, a Near Infrared Polarimetric Imager.

A preliminary analysis, performed by astronomers Pierre Bastien and
Rene Doyon from Universite de Montréal and the Centre de Recherche en
Astrophysique du Quebec (CRAQ) clearly shows a bright elongated feature
surrounding the more luminous comet’s coma. This elongated feature,
probably a cloud of dust and gas, which resembles a small tail, is
going out at position angle of 145 degrees (+/- 5 deg), measured from
north and going east. This direction makes an angle of about 33 degrees
relative to the Sun-comet direction. Although the images display
tantalizing evidence of a tail, the direction of the feature does not
point directly in the direction opposite to the Sun, as expected.

For more information, contact:

Dr. Pierre Bastien
Universite de Montreal
Tel: 1-514-343-5816
Email: bastien@astro.umontreal.ca

Image caption: The following raw images were taken with the NIR
instrument SIMON. On both images East is up and North is right.

Fig.1 : image taken with an I filter Oct 26 at 04:37 EDT (08:37 UT).

Fig.2 : same as fig.1 but with a J filter taken at 04:10 EDT (08:10 UT).