June 29, 1999
Comet Hale-Bopp - Still Enormous! (New Images - European Southern Observatory)
June 21, 1999
A Comet's Shadow in Space (Esa Science News)
Although most of the hydrogen atoms in the Solar System blow in from interstellar space, comets are surrounded by large hydrogen clouds of their own. When comet Hale-Bopp flew near the Sun parading its 100-million-kilometre-long tail in 1997, SOHO was already in orbit. In SWAN observations from that time, the scientists have now spotted a remarkable feature - never before seen by astronomers - the elongated shadow, more than 150 million kilometres long, of a comet projected on the sky beyond the comet. High-res images; Far side video sequence; Hale-Bopp video sequence
December 26, 1998
G. J. Garradd, Tamworth, N.S.W., reports that there was a remarkable3-mag brightening of the nuclear region of this comet between his CCD observations on Dec. 11 and 21.
October 22, 1998
New Observations of Comet Hale-Bopp from La Silla (ESO)
Methanol and Hydrogen Cyanide Detected at Record Distance. Observations of famous Comet Hale-Bopp continue with the 15-m Swedish-ESO Submillimetre Telescope (SEST) at the La Silla Observatory. They show amazingly strong activity of this unusual object, also at the present, very large distance from the Sun. The radio observations document in detail the release of various molecules from the comet's icy nucleus. Of particular interest is the observed emission from methanol (CH3OH) and hydrogen cyanide (HCN) molecules, never before detected in any comet this far away.
Comet Hale-Bopp still going strong. Just over 18 months after its perihelion passage on April 1, 1997, Comet Hale-Bopp (official designation C/1995 O1) is continuing its outward journey through the Solar System. It is now about 1,000 million kilometres (6.7 AU) from the Sun and the Earth, i.e. almost at the same distance as when it was first discovered in July 1995.
February 12, 1998
Overview of First International Hale-Bopp Conference - R. M. West (ESO)
The First International Meeting about Comet Hale-Bopp was held in Puerto de la Cruz (Tenerife, Canary Islands, Spain) on February 2-5, 1998. Nearly 150 specialists from all major comet research groups in the world participated. During 4 days of intensive debates and with the presentation of approximately 150 papers, the participants surveyed the current status of the many research programmes related to this most unusual comet. Overview Text
Hale-Bopp double nucleus. By very careful analysis of high-resolution HST images obtained in 1996, Zdenek Sekanina believes that the primary nucleus may have a lesser companion of approximately half the size. This issue is still somewhat controversial, but observations with the Adonis adaptive optics camera at the ESO 3.6 m telescope in November 1997 and January 1998 by three ESO astronomers also appear to show a double nucleus. (Hal Weaver images&comment)
January 30, 1998
The Unusual Tails of Comet Hale-Bopp (ESO)
Recent observations at the ESO La Silla observatory with the 1-metre Schmidt Telescope have shown that the comet is still very active and, in particular, that it still possesses an impressive tail structure. Two photos from early January 1998 are shown here; they were obtained with pan- and red-sensitive photographic film/filter combinations, respectively. They demonstrate the unusual appearance and continuing, enormous extent of this tail.
1998 to present Unusual Observations Synthesis
1997 Unusual Observations Synthesis
1996 Unusual Observations Synthesis
1995 Unusual Observations Synthesis