News - August 2002

08/30/2002

Three SOHO comets received orbits and designations: C/2002 Q6 (SOHO) is a non-group comet found by X. Leprette, C/2002 Q7 (SOHO) is a Kreutz group comet found by J. Sachs and C/2002 Q8 (SOHO) is the 9^th member of the Kracht group, found by X.-M. Zhou. SOHO has now found 504 comets. (MPEC 2002-Q46)

08/29/2002

New Discovery!: On Aug 28, 2002, the LINEAR project discovered another new comet. After posting the object on the NEO Confirmation Page several observers were able to confirm the cometary nature. The 15.5^m comet C/2002 Q5 (LINEAR) will pass perihelion according to the first and preliminary orbit on Nov. 19, 2002, at about 1.2 AU. The comet won't become much brighter since its decreasing distance to the Sun is countered by the increasing distance to Earth. The elongation of this comet is steadily decreasing (below 35° in November and December). LINEAR has now found 92 comets. (IAUC 7962, MPEC 2002-Q43)
Recovery!: F. Artigue, H. Cucurullo, and G. Trancredi (Observatorio Astronomico Los Molinos, Montevideo, Uruguay) report the recovery of comet P/1992 Q1 (= 1992p = 1992 XIV) in the course of the BUSCA program (Búsqueda Uruguaya de Supernovas, Cometas y Asteroides). Comet P/2002 Q4 (Brewington) makes its first observed return after its discovery apparition in 1992. The 16^m comet needed a correction to the prediction on MPC 40670 by +0.52 day. The comet is expected to become as bright a 10^m in early 2003. (IAUC 7961, MPEC 2002-Q41)

08/27/2002

New Discovery!: On Aug 26, 2002, the LINEAR project reported the discovery of two new comets in the same field and moving with the same apparent speed and direction. After posting the objects on the NEO Confirmation Page several observers were able to confirm the cometary nature of both objects. Comets C/2002 Q2 (LINEAR) and C/2002 Q3 (LINEAR) are indeed physically connected as indicated by the preliminary orbital elements. The comets passed perihelion around August 20, 2002, at about 1.3 AU. The first is described as being 17^m while the second seems to be 1-2^m fainter. LINEAR has now found 91 comets. (IAUC 7960, MPEC 2002-Q37)

08/19/2002

New Discovery!: Michael E. Van Ness (Lowell Observatory) reports his discovery of a new comet in the course of the LONEOS program on Aug. 17, 2002. The first and preliminary orbit for the 16^m comet C/2002 Q1 (Van Ness) indicates perihelion on July 25, 2002, at about 1.65 AU. The comet will fade. This is the 19^th new comet discovery by LONEOS. (IAUC 7956, MPEC 2002-Q08)
Z. Sekanina reports that he was able to link observations of the component A of comet 57P/du Toit-Neujmin-Delporte with its fragment F. The separation took place most likely in the second half of May 2001, 400 days before perihelion at a distance of about 3.6 AU. All attempts to confirm a separation at the 1996 apparition have failed. The derived separation velocity is about 5 m/s. The predicted separation distances and position angles (0h TT): 2002 Aug. 14, 401", 259.0 deg; 24, 398", 259.0 deg; Sept. 3, 393", 259.0 deg; 13, 387", 258.8 deg; 23, 383", 258.4 deg; Oct. 3, 381", 257.8 deg. Confirmation observations are needed. (IAUC 7957)

08/17/2002

The 501^st SOHO comet was officially confirmed. C/2002 N2 (SOHO) is the 8^th member of the Kracht group found by R. Kracht himself. (MPEC 2002-Q02).
Cometary science may have experienced a dramatic set-back when after a scheduled orbital maneuver burn of the CONTOUR spacecraft on Aug 15, no contact to the spacecraft could be established. Subsequent searches found two objects moving on the same expected trajectories for the spacecraft so it seems possible that it has broken into two pieces. More information about the ongoing events can be found on the CONTOUR website. The spacecraft was scheduled to visit the nuclei of comets 2P/Encke and 73P/Schwassmann-Wachmann 3.

08/15/2002

There is also an official NASA press release on C/2002 P3 (SOHO). The orbit - confirming the membership to the Meyer group - can be found in MPEC 2002-P63.

08/14/2002

The 500^th SOHO comet belongs to the Meyer group and is their 31^st member. R. Kracht found comet C/2002 P3 (SOHO) in real-time C2 images. This one is the first real-time comet of the new groups after their recognition. R. Kracht may also found have the 8^th member of the Kracht group - but this is until now not confirmed.

08/13/2002

A SOHO Kreutz comet, found by R. Kracht, received the designation C/2002 P2 (SOHO). This is SOHOs 499^th discovery. Actually 500^th SOHO comet has already been found: Either an uncertain and weak archival Kreutz comet claimed by D. Evans or a real-time Meyer group comet found by R. Kracht. No decision has yet been made. (MPEC 2002-P55)

08/12/2002

A very unusual asteroidal object was found by W. K. Y. Yeung (Desert Wanderer Observatory) and the NEAT program on Aug. 07, 2002. The object moves in an extremely elliptical and short-period orbit with a small perihelion distance of about 0.11 AU. The 2002 PD₄₃ designated object has an eccentricity of 0.958 and a period of about 4.2 years. No cometary activity of this 17.5^m object has been observed. This is the minor planet with the second closest perihelion distance behind the Aten 2000 BD₁₉. Additionally it is a Potentionally Hazardous Asteroid (PHA) with a current possible minimum distance to earth of about 0.035 AU. (MPEC 2002-P51)

08/11/2002

A first and very uncertain orbit for comet C/2002 P1 (NEAT) shows a very far perihelion at about 7.1 AU already in July 2001. (MPEC 2002-P46)

08/10/2002

The 30^th comet of the Meyer group was found by R. Kracht. C/2002 H8 (SOHO) is the 498^th comet discovered by the SOHO spacecraft. (MPEC 2002-P41)
D. A. J. Seargent notes that according to a formula by J. Bortle (ICQ 79, July 1991) comet C/2002 O6 might not survive its perihelion. Bortle's formula stated an empirical dependence of the survivability from the comets absolute brightness and the perihelion distance. With an absolute brightness H(0) of about 10^m and a perihelion distance q of about 0.5 AU this comet is right on the borderline for survival. It may also be possible that comet C/2002 O6 experiences a rapid decrease in brightness following perihelion. (Comet Mailing List)

08/08/2002

New Discovery!: S. Pravdo, K. Lawrence and E. Helin (JPL) report the discovery of a new comet on August 07, 2002, in the course of the NEAT program. G. Hug (Farpoint Observatory) was able to confirm the cometary nature of this 18^m object. Until now there is no orbit available for comet 2002 P1. A search ephemeris can be generated on the NEO Confirmation Page. This is NEATs 25^th comet discovery. (IAUC 7950)
H. Sato (Sukagawa, Fukushima, Japan) has prepared an animation of comet C/2002 O6 in SOHO/SWAN images. (e-mail)

08/06/2002

Three SOHO comets received orbits and designations: C/2002 K8 (SOHO) and C/2002 K9 (SOHO) were found by R. Matson, C/2002 K10 (SOHO) by D. Evans. All three comets are members of the Kreutz group. SOHO has now found 497 comets. (MPEC 2002-P17)

08/05/2002

New Discovery!: On July 29, 2002, the LINEAR project discovered an asteroidal object which showed cometary motion. After posting on the NEO Confirmation Page A. Boattini (Campo Imperatore) and J. Ticha and M. Tichy (Klet) noted a small coma. According to the first and preliminary orbit the 17.5^m comet C/2002 O7 (LINEAR) will pass perihelion in September 2003, at about 0.8 AU. It may reach 6^m but then as an exclusive southern hemisphere object. This is LINEARs 89^th comet discovery. (IAUC 7949, MPEC 2002-P13)
New Discovery!: On July 29, 2002, the NEAT program discovered a new comet. After posting on the NEO Confirmation Page this object was confirmed by A. C. Gilmore and P. M. Kilmartin (Mt John University Observatory). Additional pre-discovery images by Spacewatch (2001 May 22, June 11), LINEAR (2002 July 05) and NEAT (2002 July 16) were found. The comet is of short-period and passed perihelion already in May 2002, at about 3.2 AU. Its period is about 8.1 years. Interestingly the 14^m comet P/2002 O8 (NEAT) has a very low eccentricity (0.2). This is NEATs 24^th comet discovery. (IAUC 7949, MPEC 2002-P14)

08/04/2002

The first MPC orbit for comet C/2002 O6 confirms in general the previous orbit. The orbital inclination is lower thus leading to even worse observing conditions. From mid-European latitudes this comet will never climb higher than about 15° in the morning sky. Latest visual brightness estimations place the comet even at 7^m making a maximum brightness of 6^m in mid-August possible. (MPEC 2002-P10)
29P/Schwassmann-Wachmann is currently in outburst with about 12^m as observed by L. Focardi (Italy) and P. Manteca (Spain). (Comet Mailing List)
Z. Sekanina (JPL) reports his preliminary analysis of the breakup circumstances of comet 57P/du Toit-Neujmin-Delporte by a method developed by him and P. Chodas. The results show that component B could in fact have been broken off from the main component at the last apparition in 1996 (when a brightness outburst was observed). The origin of the other components is different: Components C-F were probably produced more recently than B, and M-T may be fragments of B. A more complex fragmentation hierarchy is possible. Additional astrometry is requested. More information and offsets and position angles for component B can be found in IAUC 7946.

08/03/2002

A very preliminary orbit for comet C/2002 O6 based on only 11 positions was published by H. Sato. It shows a perihelion on Sep. 09, 2002, at about 0.5 AU. This orbit indicates a brightness maximum of maybe 6.5^m in mid-August at the time of closest approach to Earth with about 0.22 AU. Unfortunately from mid-European latitudes this comet will be a difficult target low above the morning and beginning from Aug. 21, above the evening horizon. Latest visual estimates by J. Drummond (New Zealand) indicate a total visual brightness of about 8^m while being well condensed with a coma diameter of 6'. (Comet Mailing List)
Two SOHO comets received orbits and designations: C/2002 H7 (SOHO) and C/2002 M8 (SOHO) were both found by D. Evans and are members of the Kreutz group. SOHO has now found 494 new comets. (MPEC 2002-P08)

08/02/2002

A first and very preliminary orbit for comet P/2002 O5 (NEAT) shows this to be a short periodic comet with a period of about 6 years. It passes perihelion on August 2, 2002 (i.e. today) at about 1.2 AU. It becomes fainter. (MPEC 2002-P06)

08/01/2002

New Discovery!: Another new comet was discovered by M. Suzuki on publicly available images taken with the SWAN instrument aboard the SOHO spacecraft on July 25 and 27, 2002. Prediscovery images reach back to July 13. The comet was confirmed visually by A. Hale with about 9.5^m. No orbit for comet 2002 O6 is yet available. A search ephemeris is available on the NEO CP. The comet is fast moving with about 4 degrees per day indicating that it is quite close to Earth and very diffuse and extended. The elongation is decreasing thus making it a difficult object to observe. This is SOHOs 493^th comet discovery. (IAUC 7944)