News - December 2004

2004 December 24

Precovery observations for comet P/2004 Y1 (Christensen) by NEAT of Jan. 24, 1998, and by LONEOS of Apr. 18, 1998, were identified by the MPC. Thus this comet will most likely become 164P/Christensen. MPEC 2004-Y57)

2004 December 22

New Discovery!: Eric J. Christensen (LPL) reported the discovery of a new comet in the course of the Catalina Sky Survey on Dec. 21, 2004. After posting the 16^m comet on the NEO Confirmation Page J. Young (Table Mountain) was able to confirm the comet. With prediscovery observations by LINEAR of Dec. 09, and 15, the first orbit for comet P/2004 Y1 (Christensen) shows a perihelion already in June 2004, at about 1.6 AU. The period is about 6.9 years. This is Catalinas 15^th comet discovery. (IAUC 8458 subscription required, MPEC 2004-Y47)
Comet P/2004 V4 (NEAT) received the permanent designation 163P (NEAT).
Further SOHO Kreutz comets: C/2004 V14 (SOHO) (M. Meyer), C/2004 V15 (SOHO) (T. Hoffman), C/2004 W1 (SOHO) (T. Hoffman), C/2004 W2 (SOHO) (T. Scarmato), C/2004 W3 (SOHO) (R. Kracht), C/2004 W4 (SOHO) (B. Zhou), C/2004 W5 (SOHO) (S. Hönig) and C/2004 W6 (SOHO) (X. Leprette). Official SOHO comets: 871. (MPEC 2004-X37, MPEC 2004-X38)

2004 December 21

New Discovery!: An apparently asteroidal object, discovered on Dec. 15, 2004, by the LINEAR survey, has been - after posting on the NEO Confirmation Page - found to be cometary by J. Young (Table Mountain) and by M. Tichy (Klet). The 18^m comet C/2004 X3 (LINEAR) will pass perihelion according to the first preliminary orbit in June 2005, at about 4.4 AU. This is LINEARs 154^th comet discovery. (IAUC 8457 subscription required, MPEC 2004-Y36)

2004 December 18

As already has been suspected, comet P/2004 X1 (LINEAR) is of short period. The comet passed perihelion already on Nov. 02, 2004, at about 0.8 AU. The period is about 6 years. (MPEC 2004-Y17)

2004 December 17

New Discovery!: The bright comet currently visible in C3 images has now been officially announced. The available C3 astrometry shows that this comet is identical to the object reported by M. Mattiazzo to the CBAT on Nov. 30. It was then visible (steadily becoming brighter) in four images starting on Nov. 09. For the now 6^m comet C/2004 V12 (SWAN) a preliminary orbit has been derived. It shows a perihelion at about 0.18 AU on Dec. 21, 2004. The comet may then reach 5^m and will be visible in C3 until the day of perihelion. It will be interesting to see if the comet survives - it may be well outside the Bortle limit for comets with perihelion distances below 0.5 AU. This is SOHOs 863^th official comet discovery. The first detection in C3 images was done by J. Sachs and not by S. F. Hönig. (IAUC 8455 subscription required, MPEC 2004-Y02)

2004 December 16

The nice bright comet in SOHO/C3 images right now was already found by M. Mattiazzo in SWAN images of November 2004. No orbit is available yet. (priv. comm.)
One of two rather bright Marsden group comets - C/2004 V9 (SOHO) (H. Otterstedt) and C/2004 V10 (SOHO) (K. Battams) - might be identical with a Marsden group comet of 1999. B. G. Marsden was able to link comets C/1999 J6 (SOHO) and C/2004 V9. Since the identification of the Marsden and Kracht groups it has been suspected that these are short-periodic comets due to their possible genetical relation to 96P/Machholz, the Quadrantids and the Daylight Arietids. If the link is correct then C/1996 J6 would have passed 0.0091 AU from the moon and 0.0087 AU from the earth on 1999 June 12.
Further computations by B. G. Marsden and P. Chodas (JPL), suggest linkages Kracht Group comets C/1999 M3 = C/2004 L10 and C/1999 N6 = C/2004 J4 or C/2004 J18. (MPEC 2004-X73)
Further SOHO Kreutz comets: C/2004 V6 (SOHO) (T. Hoffman), C/2004 V7 (SOHO) (T. Hoffman), C/2004 V8 (SOHO) (K. Battams), C/2004 V11 (SOHO) (T. Hoffman) and C/2004 V12 (SOHO) (X. Leprette). Official SOHO comets: 862. (MPEC 2004-X72, MPEC 2004-X74)

2004 December 10

New Discovery!: An apparently asteroidal object, discovered by the LONEOS survey on Nov. 03, 2004, and then designated 2004 VR₈, has been found to be cometary by C. Hergenrother (Catalina) and A. Nakamura (Kuma). The 16.5^m comet P/2004 VR₈ (LONEOS) will pass perihelion at about 2.4 AU in September 2005. The period is about 10.7 years. This is LONEOS' 29^th comet discovery. (IAUC 8451 subscription required, MPEC 2004-X36)
New Discovery!: An apparently asteroidal object, discovered by the LINEAR survey on Dec. 08, 2004, has been found to be cometary after posting on the NEO Confirmation Page. C. Hergenrother (Catalina) and J. E. McGaha (Tucson) reported an 18.5^m object with a small coma and a short and curved tail. The first orbit for comet C/2004 X2 (LINEAR) - with the addition of prediscovery observations by LONEOS of Nov. 19 - shows a perihelion at about 3.8 AU, which was passed already in August 2004. This is LINEARs 153^rd comet discovery. (IAUC 8450 subscription required, MPEC 2004-X35)

2004 December 09

New Discovery!: The LINEAR survey reports the discovery of a new comet on Dec. 07, 2004. After posting on the NEO Confirmation Page several observers confirmed the cometary nature of the 16.5^m object. The very preliminary orbit shows a perihelion at about 0.8 AU, which was passed already in early November. It is likely that the comet C/2004 X1 (LINEAR) is of short period. This is LINEARs 152^nd comet discovery. (IAUC 8448 subscription required, MPEC 2004-X31)
M. Meyer (Kelkheim) was able to detect comet P/2004 V4 (NEAT) in NEAT data of 1997 and DSS images of 1990/91. The comet has thus been observed at three apparitions and will most likely receive the permanent number 163P. (MPEC 2004-X29)

2004 December 08

New Discovery!: An apparently asteroidal object discovered by the LINEAR survey on Nov. 22, and designated 2004 WR₉ has been observed to show cometary appearance by P. Birtwhistle (Great Shefford) and C. Hergenrother (Catalina). The 17.5 ^m comet P/2004 WR₉ (LINEAR) will pass perihelion in January 2005, at about 1.9 AU. The period is about 15 years. This is LINEARs 151^st comet discovery. (IAUC 8448 subscription required, MPEC 2004-X28)
Further SOHO Kreutz comets: C/2004 T6 (SOHO) (H. Su), C/2004 T7 (SOHO) (T. Hoffman), C/2004 U4 (SOHO) (B. Zhou), C/2004 U5 (SOHO) (H. Otterstedt), C/2004 U6 (SOHO) (R. Kracht), C/2004 U7 (SOHO) (X. Gao), C/2004 U8 (SOHO) (X. Leprette), C/2004 U9 (SOHO) (T. Hoffman), C/2004 U10 (SOHO) (H. Su), C/2004 U11 (SOHO) (J. Sachs) and C/2004 U12 (SOHO) (B. Zhou). Official SOHO comets: 855. (MPEC 2004-X23, MPEC 2004-X24)

2004 December 03

Comet C/2004 U1 (LINEAR) has been reported to be in outburst by Ramon Naves (Spain) and Ken-ichi Kadota (Ageo, Japan). The outburst must have ocurred between Nov. 22, and 27, 2004. On the first date the comet was still observed at only 17^m. On the latter date it was as bright as 14^m. The comet might be observable visually with larger telescopes. (Comets-ML)