IR OBSERVATIONS OF AN OUTBURST IN COMET HALE–BOPP (C/1995 O1)


    loading  Checking for direct PDF access through Ovid

Abstract

The comet Hale–Bopp (C/1995 O1)) has been observed in the infrared (1–2.5 μm)) with the Nordic Optical Telescope (NOT)) equipped with the Arcetri NICMOS3 camera (ARNICA)). Two observational campaigns, each one lasting about one week, were made when the comet heliocentric distance was about 3 AU. The first campaign was at the end of August and the second at the end of September 1996.During both runs two major outbursts were observed, the more intense of them started the day before the beginning of the second run. In the images recorded during the first three nights (24.8–26.8 Sept.)) of the second run a dust shell expanding in the northern quadrant with a projected velocity of 0.14–0.28 km/s is clearly evident. The dust production rate increased by at least a factor ≈3 at the time of the outburst. Also evident on the first night is a change in the IR color that is well correlated with the dust shell. This is an indication that the material released by the outburst has a different composition and/or size distribution than that in the ’’quiescent‘‘ dust coma.In this paper we present preliminary results about the evolution and the photometric characteristics of the dust shell.

    loading  Loading Related Articles