News - May 2001

05/30/2001

The on May 11, by NEAT discovered comet was found to be periodic as initially suspected (cf. News of May 13, and 16). Pre-Discovery observations by Spacewatch of October 2000, were additionally identified by T. B. Spahr. Comet P/2001 J1 (NEAT) passed its perihelion in March 2001 at about 0.94 AU. The period P is about 7.6 years. (IAUC 7635, MPEC 2001-K43)

05/28/2001

New Discovery!: An asteroidal object discovered on May 17, in the course of the LINEAR program was found to be diffuse by M. Tichy and J. Ticha (Klet) and C. W. Hergenrother, T. B. Spahr, and M. Nelson (Mt. Graham). Prediscovery images by LINEAR of Apr. 30, 2001, were also found. Comet C/2001 K5 (LINEAR) - the 60^th new comet found by this project - is about 14^m and will pass its perihelion in October 2002, at about 5.2 AU. The instrinsically bright comet may reach 12^m in 2002. (IAUC 7634, MPEC 2001-K40)

05/24/2001

Another SOHO comet fragment was found by D. Biesecker and received the designation C/2001 K4 (SOHO). (MPEC 2001-K27)

05/23/2001

New Discovery!: B. A. Skiff (Lowell Obs.) reports the discovery of a new comet in the course of the LONEOS program on May 22, 2001. The 15.5^m comet C/2001 K3 (Skiff) - the 15^th found by LONEOS - passed its perihelion in January 2001 at about 1.9 AU according to the first preliminary orbit. (IAUC 7631, MPEC 2001-K24)

05/22/2001

New Discovery!: S. Pravdo, E. Helin and K. Lawrence (JPL) report the discovery of a new comet on May 20, 2001, in the course of the NEAT program. Prediscovery images by LONEOS (2001 Feb. 02, Apr. 25 and May 18) and LINEAR (2001 Apr. 15) were identified by T. B. Spahr (MPC). The 16.5^m comet P/2001 K1 (NEAT) passed its perihelion already in November 2000, at about 2.5 AU. The comet has an orbital period of about 7.6 years. (IAUC 7629, MPEC 2001-K17)
Additional observations of the offsets of components A and B of the split comet C/2001 A2 (LINEAR) indicate a date of splitting of March 29.9 +/- 1.6 UT, according to Z. Sekanina (JPL). This date coincides with the date of the major outburst. (IAUC 7630)
The 314^th comet discovered by SOHO received the designation C/2001 K2 (SOHO) and was found by M. Oates. (MPEC 2001-K19)

05/18/2001

Comet C/2001 A2 (LINEAR), which has split, continues to brighten and shows interesting processes within the inner coma for southern hemisphere observers. Current visual brightness estimations put the comet at 4^m - 5^m with tail lengths up to 4°. (Garradd, MPML) Additionally, observations with the VLT on May 14, and 16, 2001, indicate a splitting of the component B into another two pieces. (IAUC 7627) Images of the split comet taken at Los Molinos (Uruguay) and from Brazil. (MPML)
Also, there are new press releases about the disintegration of comet C/1999 S4 (LINEAR) last summer: Space Telescope Science Institute, JPL and John Hopkins University.

05/16/2001

The on May 11, by NEAT discovered comet (cf. news item of May 13) has been designated as C/2001 J1 (NEAT). A first and very indeterminate orbit indicates a perihelion on Mar 19, 2001, almost exactly at 1 AU. It is not yet clear if the comet is of short period. The object is intrinsically faint with an absolute magnitude of about 15^m. (IAUC 7625, MPEC 2001-J34)
J. Broughton (Reedy Creek, Queensland) reports his observations of the nuclear components of comet C/2001 A2 (LINEAR) indicating brightness variations of the two nuclei in the timescale of at least 24 hr. Additionally, Z. Sekanina (JPL) calculated a separation time of Mar 17 +/- 12 days with acceleration values of 7.1 +/- 2.4 in units of 10^-5 solar gravity. (IAUC 7625)
Another three SOHO comets received orbits and designations: C/2001 J2 (SOHO) was found by K. Cernis, C/2001 J3 (SOHO) by M. Oates and C/2001 J4 (SOHO) by X. Leprette. (MPEC 2001-J35)

05/15/2001

New Discovery!: S. Pravdo, E. Helin and K. Lawrence (JPL) report the discovery of another new comet on May 14, 2001, in the course of the NEAT program. T. B. Spahr (MPC) was able to identify this object with an apparently asteroidal object, designated 2001 HT₅₀, which was observed by LINEAR on Apr. 23, 2001, and by LONEOS on Apr. 26, 2001 (MPS 30375). Further pre-discovery observations by NEAT of Mar. 23, 2001, and by LINEAR of Mar. 03, 2001, were subsequently found. The now 17.5^m comet C/2001 HT₅₀ will pass its perihelion in July 2003 at about 2.8 AU. The comet may become visible in medium-sized telescopes with about 13^m in October 2002. It will then remain visible for mid-European observers until May 2003, and reach a brightness of perhaps 11^m. Another observing window opens in August 2003. The comet may reach a maximum brightness of maybe 10^m in October 2003, and remain visible until March 2004. (IAUC 7624, MPEC 2001-J31)

05/13/2001

New Discovery!: S. Pravdo, E. Helin, and K. Lawrence (JPL) report the discovery of a new comet in the course of the NEAT program on May 11, 2001. The 17^m comet 2001 J1 was confirmed by L. Sarounova (Ondrejov) and by M. Tichy and J. Ticha (Klet). No orbit is available yet. A search ephemeris can be found on the NEO Confirmation Page. (IAUC 7623)

05/04/2001

The 310^th comet discovered by SOHO received an orbit and a designation. Comet C/2001 H7 (SOHO) was found by S. Hönig in real-time images of the LASCO coronagraph . (MPEC 2001-J03)

05/02/2001

Comet C/2001 A2 (LINEAR), which experienced a strong brightness outburst in the previous weeks and which did not became fainter afterwards shows - according to observations by C. W. Hergenrother, M. Chamberlain and Y. Chamberlain (Lunar and Planetary Laboratory, University of Arizona) - a double nucleus. Images of Apr. 30, 2001, show two components, equal in brightness and about 3.5" apart, aligned exactly in east-west direction. Both components are highly condensed. Images with the same instrument of Apr. 24, 2001, only show one nucleus. With this observation it is once more uncertain if the comet will sustain this brightness level much longer. Recent observation of this comet - which is not visible from mid-Europe - indicate a visual brightness of about 6.5^m, suggesting a possible maximum brightness of about 4^m. (IAUC 7616)