Comet Hale-Bopp

Hale-Bopp at 2 Billion kmThis is the ESO Homepage for the unusual Comet 1995 O1 (Hale-Bopp). It will be updated regularly as new information and images, from ESO as well as from other sources, become available.

This page contains general information, in particular summaries and updates about the current situation. From here there is also access to other pages with supplementary, more specialised information, including one with links to other Hale-Bopp sites.

Latest news (March 6, 2001)

An image was obtained on 27 February – 2 March, 2001 with the Wide-Field Imager (WFI) at the ESO La Silla Observatory, cf. eso0108. It shows that Comet Hale-Bopp is still active at a distance of about 2000 million km from the Sun. It is also a very large object, measuring at least 2 million km across.

Recent magnitude estimates may be found at the special webpage at the "International Comet Quarterly".

A group of astronomers led by Alan Stern (South-West Research Institute, USA) announced in early June 2000 the discovery of the noble gas argon in Comet Hale-Bopp. The astronomers made the observation on 29 March, 1997, by means of an ultraviolet-sensitive instrument on a sounding rocket. More details are available, e.g. in a report published on 5 June, 2000 at

Images from the 3.5-m New Technology Telescope at La Silla have been published at the ESO website on 29 June, 1999, cf. eso9933. They showed that Comet Hale-Bopp still possessed an enormous halo.

Comet Hale-Bopp Updates

Images, Links, etc.