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 17/P Holmes, obtained with the 1.6m Ritchey-Chretien telescope at Mont Mégantic 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 René Doyon from Université de Montréal and the Centre de recherche en astrophysique du Québec (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 215 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:

Dr. Pierre Bastien
Université de Montréal
Tel: (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 down 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).

http://www.astro.umontreal.ca/~casca/PR/holmes_I.png
http://www.astro.umontreal.ca/~casca/PR/holmes_J.png