News - November 1999

11/25/1999

New Discovery!: Doug Biesecker discovered a very faint sungrazing comet (the 92^nd comet discovered by SOHO) in data of the C2 coronagraph aboard the SOHO spacecraft on Nov. 23, 1999. The comet has not yet been announced officially by the CBAT. (Sungrazer Homepage)

11/23/1999

A part of issue 3 (Vol. 77) of the journal EARTH MOON AND PLANETS deals with comet C/1995 O1 (Hale-Bopp). Besides reports on the size of the comets nucleus, its origin and chemical composition, a report on the detection of a companion of the comets main nucleus is given. The abstracts can be found here. (CCNet)

11/21/1999

C. W. Hergenrother and S. Larson (Lunar and Planetary Laboratory) report about CCD observations of comet 10P/Tempel 2 with the Steward Observatory 2.3-m reflector by Hergenrother on Nov. 13, 1999. These show a shell-like jet-arc coma structure. Further observations over a time span of 1.5 h did reveal no obvious changes of this structure. A processed image can be found here. (IAUC 7313)

11/09/1999

A first and preliminary orbit for comet C/1999 V1 (Catalina) indicates the perihelion on Sep. 15, 1999 at about 3.1 AU. (IAUC 7305, MPEC 1999-V29)

11/06/1999

New Discovery!: C. W. Hergenrother (Lunar and Planetary Laboratory) reports the discovery of a 17^m comet in the course of the Catalina Sky Survey on Nov. 05, 1999. No orbit is available yet for comet 1999 V1. (IAUC 7302)
A new orbit for comet 1999 U3 indicates a short-period nature. Comet P/1999 U3 (LINEAR) passed its perihelion on Nov. 05, 1999, at about 1.9 AU. The period is about 12.5 years. (IAUC 7302, MPEC 1999-V17)
S. Nakano reports observations of comet 63P/Wild 1 which was not observed at its last apparition in 1986. The comet is about 16^m. These observations confirm a single-night detection by C. W. Hergenrother on Feb. 14, 1999, at about 22^m. The correction to the prediction is about -0.35 days. The comet will pass its perihelion on Dec. 27, 1999, and become as bright as about 14^m - 15^m. (IAUC 7302, MPEC 1999-V18)

11/04/1999

On Oct. 03, 1999, the Spacewatch project discovered an unusual asteroidal ocject. The 19^m faint asteroid 1999 TD10 moves on a long-period orbit (P about 1900 years) with a perihelion distance of about 11.6 AU. No signs of a coma have been observed yet. (MPEC 1999-T46, V07)

11/02/1999

R. H. McNaught (Research School of Astronomy and Astrophysics, Siding Spring Observatory, AUS) was able to observe another component of comet 141P/Machholz 2 that split in 1994. Independent observations were also reported by A. Sugie (Dynic Observatory, JAP). Brian Marsden was able to link these observations with the component D of 1994 without using nongravitational forces. The observations by Michael Jäger and Gerald Rhemann (cf. News of Nov. 01, 1999) belong also to the component D, which is now brighter than component A and has currently a distance of about 7' to it. (IAUC 7299)
New Discovery!: T. B. Spahr (Lunar and Planetary Laboratory) reports the discovery of a slow moving object in the course of the Catalina Sky Survey on Oct. 31, 1999. One day later this object was independently discovered by B. A. Skiff in the course of the LONEOS program. Further observations by R. L. Millis and L. H. Wasserman as well as by M. Tichy and Z. Moravec (Klet, SLK) revealed a small coma. Comet C/1999 U4 (Catalina-Skiff) is about 17^m and will pass its perihelion according to the first and very preliminary orbit in September 2001 in a distance of about 4.8 AU and may reach about 14^m. (IAUC 7298, MPEC 1999-V04)

11/01/1999

Michael Jäger and Gerald Rhemann obtained first photographic images of comet 141P/Machholz 2, which split in 1994, showing the comet at about 13^m. The images can be found on the Homepage (in German) of both well-known astro-photographers. (WWW)
New Discovery!: R. Huber reports the discovery of the 35^th comet of the LINEAR program on Oct. 30, 1999. Comet C/1999 U3 (LINEAR) is about 16.5^m and passed its perihelion according to the first orbit already on Sep. 12, 1999, at about 1.8 AU. (IAUC 7295, 7296)
New Discovery!: Doug Biesecker discovered the faint sungrazer SOHO-91 in data of the C3 coronagraph aboard the SOHO spacecraft on Oct. 31, 1999. The comet has not yet been announced officially by the CBAT. (Sungrazer Homepage)