News - July 2005

2005 July 26

R. Kracht (Elmshorn) has found another two Kreutz comets in images of the Solwind mission. C/1983 N2 (SOLWIND) and C/1984 Q1 (SOLWIND) were both about 2-3^m and almost starlike with a possible tail in some of the images. These are the 8^th and 9^th SOLWIND comets. A third comet in data of 1984 Sep. 15, seems to be a non-group comet. It is currently being checked if it was also seen by the SMM mission. Until now no comets of the new comet groups have been detected in SOLWIND data. R. Kracht has prepared a special page about his SOLWIND discoveries. (IAUC 8573, subscription required)
Comet P/1998 W2 = P/2005 N2 has received the permanent designation 168P/Hergenrother.

2005 July 24

Further SOHO Kreutz comets: C/2005 L14 (SOHO) (T. Hoffman), C/2005 L15 (SOHO) (X. Leprette), C/2005 M2 (SOHO) (K. Battams), C/2005 M4 (SOHO) (J. Zhang) and C/2005 M5 (SOHO) (T. Hoffman). C/2005 M3 (SOHO) (H. Su) belongs to no known comet group. Official SOHO comets: 984. (MPEC 2005-O26, IAUC 8572, subscription required)

2005 July 15

Further SOHO Kreutz comets: C/2005 L7 (SOHO) (T. Hoffman), C/2005 L8 (SOHO) (H. Su), C/2005 L9 (SOHO) (B. Zhou), C/2005 L10 (SOHO) (K. Cernis), C/2005 L11 (SOHO) (B. Zhou), C/2005 L12 (SOHO) (T. Hoffman) and C/2005 L13 (SOHO) (H. Su). Official SOHO comets: 978. (MPEC 2005-N75, MPEC 2005-N76)

2005 July 14

New Discovery!: An apparently asteroidal object, discovered on July 06, 2005, in the course of the Catalina Sky Survey and which was then posted on the NEO Confirmation Page has been found to be cometary by J. Young (Table Mountain) and P. Birtwhistle (Great Shefford). The first orbit for the 19^m comet C/2005 N4 (Catalina) shows the perihelion on July 02, 2005, at about 2.3 AU. This is the 21^st comet discovery by the Catalina Sky Survey. (IAUC 8568, subscription required, MPEC 2005-N73)
New Discovery!: Another apparently asteroidal object, discovered on July 12, 2005, in the course of the catalina Sky Survey and which was then posted on the NEO Confirmation Page has been found to be cometary again by J. Young (Table Mountain) and P. Birtwhistle (Great Shefford). The first and preliminary orbit for the 17^m comet C/2005 N5 (Catalina) shows the perihelion on Aug. 20, 2005, at about 1.6 AU. The comet may be of short period. This is the 22^nd comet discovery by the Catalina Sky Survey. (IAUC 8568, subscription required, MPEC 2005-N73)

2005 July 13

R. Kracht (Elmshorn) reports his discovery of a previously unrecognised Kreutz comet in images taken with the Solwind spacecraft on Nov. 20, 1981. Comet C/1981 W1 (SOLWIND) was fainter than the other six Solwind comets - about 2-3^m - and showed a small tail. (IAUC 8566 subscription required)

2005 July 12

Further SOHO Kreutz comets: C/2001 Q9 (SOHO) (R. Kracht), C/2001 S3 (SOHO) (R. Kracht), C/2005 K10 (SOHO) (K. Battams), C/2005 L5 (SOHO) (H. Su) and C/2005 L6 (SOHO) (T. Hoffman and S. F. Hönig).
C/2005 K9 (SOHO) (R. Kracht) is the 58th member of the Meyer group. Official SOHO comets: 971. (IAUC 8563 subscription required, IAUC 8565 subscription required, MPEC 2005-N60)
Z. Sekanina (JPL) reports that a two-parameter version of his comet fragmentation model for 24 astrometric observations from Jun. 25, to Jul. 9, 2005, indicates a separation of the secondary nucleus of comet C/2005 A1 (LINEAR) on 2005 Apr. 23.4 +/- 0.8 days. The fragment may remain observable for many months. (IAUC 8562 subscription required)

2005 July 11

101P/Chernykh was recovered by J. Young (Table Mountain Observatory) on July 10, and 11, 2005. he orbital solution covers only the timespan well after the comet's split in 1991 until now. (MPEC 2005-N59)
The latest SOHO 'Hot Shot' nicely illustrates the suspected family tree of some Marsden group comets.

2005 July 10

As initially suspected, comet 2005 N3 was confirmed to be of short period with the help of further astrometry. Comet P/2005 N3 (Larson) will pass perihelion on Dec. 08, 2005, at about 2.2 AU. The period is about 6.7 years. (MPEC 2005-N46)

2005 July 06

New Discovery!: S. Larson reports his discovery of a new comet on July 03, 2005, in the course of the Mt. Lemmon Survey. R. H. McNaught was able to confirm the comet at Siding Spring. The first and very uncertain orbit for the 19.5^m comet C/2005 N3 (Larson) shows a perihelion on Dec. 18, 2005, at about 1.3 AU. The comet is probably of short period. This is the 3^rd comet discovery by the Mt. Lemmon Survey. (IAUC 8560, subscription required, MPEC 2005-N29)
D. Herald (Kambah, near Canberra) reports his recovery of comet P/1998 W2 on July 4 and 5. The 19.5^m comet P/2005 N2 (Hergenrother) will pass perihelion on Nov. 02, 2005, at about 1.4 AU. The correction to the prediction was +0.27 days. It is expected to become as bright as 16^m. This comet will most likely receive the permanent numbering 168P. (IAUC 8560, subscription required, MPEC 2005-N28)

2005 July 05

Another comet has been reported to have split. Observations by S. Pastor and J. A. Reyes (La Murta) of comet C/2005 A1 (LINEAR) show a secondary condensation fainter than the primary one. Confirmatory images were obtained by Giovanni Sostero and Ernesto Guido (remotely near Mayhill). (MPEC 2005-N21, CometsML)
Further astrometry for has identified comet 2005 M1 as being of short period. Comet P/2005 M1 (Christensen) will pass perihelion on Jan. 31, 2006, at about 2.9 AU. The period is about 8.6 years. (MPEC 2005-N20)

2005 July 04

The Deep Impact mission was a full success. Nice collections of the events and images and movies can be found at the Planetary Society and at Spaceflight Now. The few available visual observation up to now showed only a slight increase in brightness but a large increase in the degree of condensation. Further visual monitoring is strongly encouraged.

2005 July 03

New Discovery!: C. W. Juels (Fountain Hills, USA) and P. R. Holvorcem (Campinas, Brazil) report their discovery of a new comet on July 02, 2005, with a 7-cm lens + CCD. After posting on the NEO Confirmation Page J. E. McGaha (Tucson), C. W. Hergenrother (Lunar and Planetary Laboratory) and L. Buzzi and F. Luppi (Varese) were able to confirm the nature of the 14.5^m object. With prediscovery observations by Juels and Holvorcem of June 30, and July 01, 2005, the first orbit for comet C/2005 N1 (Juels-Holvorcem) indicates perihelion on Aug. 21, 2005, at about 1.1 AU. The comet will become only slightly brighter and stays at low elongations to the sun.
This is the first amateur comet discovery of 2005, and the second credited comet discovery of the team Juels/Holvorcem. They also recovered the lost comet 157P/Tritton in 2003. (IAUC 8557, subscription required, MPEC 2005-N10)

2005 July 01

On July 04, 2004, at about 06:00 UT the 300 kg copper projectile of the spacecraft Deep Impact should smash into comet 9P/Tempel, which is currently at about 10-11^m. How large the brightness surge will finally be is still unclear. Unfortunately the comet is extremely unfavourably placed to observe. With tolerable dark skies it will climb not higher than 8 deg above the horizon and needs a very clear view at the horizon and a large telescope due to the higher extinction at 82 deg zenithal distance. The larger values of height above the horizon quoted somewhere else are only possible at beginning dawn and mean an even worse visibility. A collection of web feeds can be found here.