News - November 2004

2004 November 24

New Discovery!: A new comet discovered by the LINEAR survey on Nov. 20, was identified with the apparently asteroidal object 2004 RG₁₁₃, found by LINEAR on Sep. 06, and observed by them regularly in September, October and November. Comet C/2004 RG₁₁₃ (LINEAR) will pass perihelion on Mar. 03, 2005, at about 1.9 AU. The now 17.5^m comet may then reach 16^m. This is LINEARs 150^th comet discovery. (IAUC 8444 subscription required!, MPEC 2004-W38)
New permanent comet numberings: P/1983 V1 = 2004 V2 = 161P/Hartley-IRAS and P/2004 TU₁₂ = 162P/Siding Spring.
Z. Sekanina (JPL) reports that his fragmentation model shows that the splitting of the nucleus of comet P/2004 V5 (LINEAR-Hill) occurred around 2001.9 +/- 0.3 years at a heliocentric distance of about 6.3 AU and 2.5 prior perihelion. (IAUC 8440 subscription required!,

2004 November 13

The IAU Committee on Small-Body Nomenclature has decided to change the name and principal designation of comet P/2003 YM₁₅₉, because the Catalina observer R. Hill was alone in discovering, measuring, and reporting the double comet. The comet now receives the new principal designation: P/2004 V5 (LINEAR-Hill). (IAUC 8438 subscription required, MPEC 2004-V79)

2004 November 13

New Discovery!: On Oct. 10, 2004, the Siding Spring Survey discovered a bright and apparently asteroidal object in an unusual (Amor-like) orbit. The object was then designated 2004 TU₁₂ and quickly earlier observations were found: One trail on a Palomar plate of March 1990, and several detections in NEAT data of 2000 through 2003. The object passed perihelion on Nov. 10, 2004. Images taken by F. Mallia, G. Masi, and R. Wilcox (Las Campanas) on Nov. 12.0 UT and images taken by Juan Lacruz (La Canada) on Nov. 12.8 UT, show a fine and short tail of the otherwise stellar object. Comet P/2004 TU₁₂ (Siding Spring) is about 14^m and has a period of about 5.3 years. This is the 5^th comet discovery by the Siding Spring Survey and will most likely receive the permanent number 162P. (IAUC 8436, subscription required!, Comets Mailing List)

2004 November 11

New Discovery!: On Nov. 10, 2004, the Catalina Sky Survey observed two possible comets which were only about 2 arcmin apart. With the assumption that both comets are related and only have a difference in T, B. G. Marsden (Harvard-Smithsonian Center for Astrophysics) concluded that these objects have to be intermediate-period comets about 4.4 AU from the earth. This lead to further observations taken by the LINEAR survey on Oct. 08, and 24, 2004. With the help of this three-night orbit the identity of the brighter component A with the asteroidal object 2003 YM₁₅₉, observed by LINEAR on Dec. 17, and 30, 2003, (MPS 109905) could be revealed.
The 17.5^m comet P/2003 YM₁₅₉ (LINEAR-Catalina) will pass perihelion on Feb. 28, 2005, at about 4.4 AU. The period is about 22.4 years. This is LINEARs 149^th and Catalina's 14^th comet discovery. (IAUC 8433, MPEC 2004-V52)
Z. Sekanina (JPL) reports about his results of the analysis of the splitting of comet C/2004 S3 (LINEAR). He concludes that component B is the main component, something that is also supported by the position of component A between components B and C, a possible third fragment, on an image by R. Ferrando on Oct. 9, 2004. Assuming a radial component of the separation velocity from B of about 0 to 2 m/s, the time of splitting lies between May 23, and June 17, 2004 (3 days before to 22 days after perihelion) at 3.86 AU from the sun. (IAUC 8434)

2004 November 09

Comets P/2004 V3 (Siding Spring) and P/2004 V4 (NEAT) have now been identified as short-periodic ones. P/2004 V3 passes perihelion on Nov. 19, 2004, at about 3.9 AU, the period being about 20 years. P/2004 V4 passes perihelion on Jan 31, 2005, at about 1.9 AU with a period of about 7 years. (MPEC 2004-V45, MPEC 2004-V46)

2004 November 07

New Discovery!: On Nov 3, R. H. McNaught (Siding Spring Observatory) reported the discovery of an object on images taken by G. J. Garradd in the course of the Siding Spring Survey. On Nov. 05, and 06, McNaught found the 18^m object to be diffuse. The first orbit for comet C/2004 V3 (Siding Spring) shows a perihelion on Jan. 22, 2005, at about 4.2 AU. This is the 4^th comet discovery of the Siding Spring Survey. (IAUC 8429, MPEC 2004-V33)
New Discovery!: K. J. Lawrence (JPL) reports the discovery of a new comet in the course of the NEAT survey on Nov. 05. R. H. McNaught was able to confirm the cometary nature of the object. The 18^m comet C/2004 V4 (NEAT) is probably of short-period. The first MPC orbit is still a parabolic one, with perihelion in March 2005, at about 1.3 AU. The short-period solution shows a perihelion in Dec. 2004, at about 2 AU, with a period of about 7 years. This is NEATs 47^th comet discovery. (IAUC 8429, MPEC 2004-V34)
Three previously unnamed comets were finally named by the IAU Committee on Small Bodies Nomenclature:
C/1996 R3 (Lagerkvist) was reported some time after its discovery and the resulting orbit was very uncertain. Re-measurements by M. Meyer in Dec. 2003, allowed to improve the orbit considerably, allowing C.-I. Lagerkvist to detect additional images which finally lead to a longer arc and secure orbital elements.
P/2003 A1 (LINEAR) is probably identical with D/1783 W1 (Pigott). Current data do not allow an unambiguous linkage of both comets.
P/2004 A1 (LONEOS) (IAUC 8430)

2004 November 06

Recovery!: R. H. McNaught (Siding Spring Observatory) was able to recover comet P/1983 V1 (Hartley-IRAS) (= 1983v = 1984 III) on Nov. 3, and 5, 2004. The 18^m comet P/2004 V2 (Hartley-IRAS) was about -4.8 days off the predicted position. It will pass perihelion on June 20, 2005, at about 1.3 AU. This is the first apparition after its discovery in 1983. At that time the comet showed a unique lightcurve peaking nearly two months after perihelion with a likely outburst to about 8^m. The prediction for this apparition is 10^m in July 2005, but in view of the lightcurve of 1983 it might become brighter. For central European observers the comet will become observable in June 2005, then reaching declinations of about 80° in July. A close photometric monitoring of this comet is strongly recommended.
The comet now qualifies for a permanent numbering, most likely 161P/Hartley-IRAS. (IAUC 8428, MPEC 2004-V25)

2004 November 05

New Discovery!: On Nov. 04, B. Skiff (Lowell Observatory) reported the discovery of a new comet in the course of the LONEOS survey. After posting on the NEO Confirmation Page B. L. Stevens (Las Cruces) was able to confirm the cometary nature of the 18^m object. With the help of pre-discovery observations by LINEAR of Oct. 7, and 18, the first orbit for comet P/2004 V1 (Skiff) shows a perihelion on Dec. 8, 2004, at about 1.4 AU. The comet has a period of about 10 years. This is LINEARs 148^th comet discovery. (IAUC 8426, MPEC 2004-V16)

2004 November 02

The 51^st member of the Meyer group, C/2004 U3 (SOHO), was found by K. Battams. Further SOHO Kreutz comets: C/2004 S3 (SOHO) (K. Battams), C/2004 S4 (SOHO) (Y.-S. Tsai), C/2004 S4 (SOHO) (H. Su), C/2004 T4 (SOHO) (H. Su) and C/2004 T5 (SOHO) (R. Kracht). Official SOHO comets: 844. (MPEC 2004-V05)
Comet C/2004 T3 has been named C/2004 T3 (Siding Spring).