News - April 2004

2004 Apr 30

Further SOHO backlog comets (all Kreutz group): C/2003 N1 (SOHO) (X. Leprette, J. Sachs), C/2003 N2 (SOHO) (J. Sachs), C/2003 O4 (SOHO) (J. Sachs), C/2003 O5 (SOHO) (J. Sachs), C/2003 O6 (SOHO) (X.-M. Zhou), C/2003 O7 (SOHO) (M. Boschat), C/2003 O8 (SOHO) (J. Sachs), C/2003 P1 (SOHO) (M. Boschat) and C/2003 P1 (SOHO) (M. Boschat). Current official SOHO score: 653 comets. (MPEC 2004-H87, MPEC 2004-H88)

2004 Apr 24

New Discovery!: J. A. Larsen (LPL) reported his discovery of another new comet on Apr. 22, 2004, in the course of the Spacewatch survey. After posting on the NEO Confirmation Page several follow-up observer were able to confirm the cometary nature. The 18.5^m comet P/2004 H3 (Larsen) has already - according to the first preliminary and uncertain orbit - passed perihelion in February 2004, at about 2.5 AU. The period is about 8.5 years. This is the 25^th comet discovery by Spacewatch. (IAUC 8332, MPEC 2004-H66)
Further SOHO backlog comets (all Kreutz group): C/2003 K13 (SOHO) (D. Evans), C/2003 M8 (SOHO) (X.-M. Zhou), C/2003 M9 (SOHO) (X.-M. Zhou), C/2003 M10 (SOHO) (X.-M. Zhou), C/2003 M11 (SOHO) (X. Leprette) and C/2003 M12 (SOHO) (R. Kracht, X. Leprette). Current official SOHO score: 644 comets. (MPEC 2004-H49)

2004 Apr 22

A first post-perihelion image of comet C/2004 F4 (Bradfield) taken on the morning of Apr. 22, by Michael Jäger (Austria) 70 min prior sunrise at about 14 deg elongation. (personal communication)
New Discovery!: J. A. Larsen (LPL) reported his discovery of a new comet on Apr. 19, 2004, in the course of the Spacewatch survey. After posting on the NEO Confirmation Page several follow-up observer were able to confirm the cometary nature. The 19^m comet P/2004 H2 (Larsen) will - according to the first preliminary and uncertain orbit - pass perihelion in August 2004, at about 2.6 AU. The period is about 9.5 years. This is the 24^th comet discovery by Spacewatch. (IAUC 8328, MPEC 2004-H42)

2004 Apr 18

New Discovery!: An asteroidal object discovered by the LINEAR survey on Apr 16, 2004, has been found to be cometary by follow-up observers. The 19^m comet C/2004 H1 (LINEAR) has - according to the first preliminary orbit - already passed perihelion in January 2004, at about 1.2 AU. This is LINEARs 140^th comet discovery. (IAUC 8325, MPEC 2004-H26)
Further SOHO backlog comets (all Kreutz group): C/2003 L8 (SOHO) (R. Kracht), C/2003 M1 (SOHO) (R. Kracht, K. Cernis), C/2003 M2 (SOHO) (J. Sachs), C/2003 M3 (SOHO) (R. Kracht), C/2003 M4 (SOHO) (R. Kracht), C/2003 M5 (SOHO) (M. Boschat), C/2003 M6 (SOHO) (R. Kracht) and C/2003 M7 (SOHO) (X.-M. Zhou). Current official SOHO score: 638 comets. (MPEC 2004-H20, MPEC 2004-H21)

2004 Apr 16

C/2004 F4 (Bradfield) has entered the SOHO/C3 field of view yesterday at 20:18 UT. The expected trajectory can be seen here. With the SOHO data the orbit will be improved within the coming days.
The 42^nd Meyer group comet was found by T. Hoffman. C/2004 G2 (SOHO) was faint and only seen in four images at the very adge of the C2 field of view. There are still 5 additional Meyer group comets pending. Official SOHO score: 630 comets. (MPEC 2004-H01)

2004 Apr 15

New Discovery!: An asteroidal object, discovered on Mar. 14, and 16, 2004, by the Catalina and LINEAR surveys has been found to be cometary independently by M. T. Read and J. A. Larsen (Kitt Peak) and C. W. Hergenrother (Mt. Hopkins). The 18.5^m comet P/2004 EW₃₈ (Catalina-LINEAR) passed perihelion on Nov 19, 2003, at about 1.8 AU. The period is about 6.8 years. This is Catalina's 12^th and LINEARs 139^th comet discovery. (IAUC 8322, MPEC 2004-G46)
New Discovery!: An asteroidal object, discovered on Feb. 18, and 19, 2004, by the Catalina and LINEAR surveys has been found to be cometary by S. S. Sheppard, Y. R. Fernandez, and D. Jewitt (Mauna Kea). The 18^m comet C/2004 DZ₆₁ (Catalina-LINEAR) will pass perihelion on May 26, 2004, at about 2 AU. This is Catalina's 11^th and LINEARs 138^th comet discovery. (IAUC 8321, MPEC 2004-E02, MPEC 2004-G34)

2004 Apr 13

It is possible that C/2004 F4 (Bradfield) may not survive perihelion. According to an empirical formula by J. Bortle the absolute brightness of this comet may be below the survival threshold. However, the absolute brightness is not yet known for sure. (Comets Mailing List

2004 Apr 12

New Discovery!: William A. Bradfield discovered a new comet visually on Mar. 23, 2004, while searching for sungrazing comets. He was able to follow it the next day but the final confirmation was not possible until Apr. 8. Afterwards the comet was confirmed by several southern observers who reported a 3-4^m comet with a short tail. The first and very preliminary orbit indicates that comet C/2004 F4 (Bradfield) will pass perihelion on Apr. 17, 2004, at about 0.17 AU. It may reach 2^m at perihelion which will be visible in SOHO/C3 images. For central European observers the comet will become visible at the end of April/ beginning of May with about 6^m in the morning sky. This is William Bradfields 18^th visual comet discovery. (IAUC 8319, IAUC 8320)

2004 Apr 11

New Discovery!: The LINEAR survey reports the discovery of a new comet on Apr 09, 2004. The 18^m comet C/2004 G1 (LINEAR) will - according to the first preliminary orbit - pass perihelion in June 2004, at about 1.2 AU. This is LINEARs 137^th comet discovery. (IAUC 8318)
Further SOHO backlog comets (all Kreutz group): C/2003 K10 (SOHO) (P. Shkreby), C/2003 K11 (SOHO) (D.-H. Chen), C/2003 K12 (SOHO) (T. Hoffman), C/2003 L3 (SOHO) (X. Leprette), C/2003 L4 (SOHO) (R. Kracht, M. Meyer), C/2003 L5 (SOHO) (R. Kracht), C/2003 L6 (SOHO) (P. Shkreby) and C/2003 L7 (SOHO) (M. Boschat). Current official SOHO score: 629 comets. (MPEC 2004-G19, MPEC 2004-G20)