News - October 2005

2005 October 30

New Discovery!: M. T. Read reports his discovery of a 20^m comet in the course of the Spacewatch survey. Confirmation was obtained by T. H. Bressi (Spacewatch), T. Gehrels (Spacewatch), J. V. Scotti (Spacewatch), and E. J. Christensen (Mt. Lemmon). The preliminary orbital elements with the help of Catalina prediscovery observations of Oct. 23, 2005, for comet P/2005 U1 (Read) indicate perihelion already on Jul. 07, 2005, at about 2.3 AU. The period is about 5.9 years. This is the 31^st comet discovery by Spacewatch. (IAUC 8624, subscription required, MPEC 2005-U74)
J. Young (Table Mountain) reports the discovery of a faint (20^m) secondary component of comet C/2004 U1 (LINEAR) on images taken by D. Mayes. (IAUC 8624, subscription required)

Further SOHO comet discoveries (all named SOHO):

Designation  Group   Discoverer  Notes
C/2005 Q7    Kreutz  S. Farmer
C/2005 Q8    Meyer   H. Su       61st member of the Meyer group
C/2005 Q9    Kreutz  S. Farmer
C/2005 Q10   Kreutz  B. Zhou
C/2005 R5    Kreutz  H. Su
C/2005 R6    Kreutz  H. Su
C/2005 R7    Kreutz  H. Su
C/2005 S5    Kreutz  H. Su
C/2005 S6    Kreutz  H. Su
C/2005 S7    Kreutz  H. Su
C/2005 S8    Kreutz  Q. Ye
C/2005 S9    Kreutz  H. Su
C/2005 S10   Kreutz  T. Chen
C/2005 S11   Kreutz  H. Su

SOHO comets: 1024. (MPEC 2005-U71, MPEC 2005-U72, MPEC 2005-U85)

2005 October 27

C. W. Hergenrother (Lunar and Planetary Laboratory) reports his recovery of component C of comet 73P/Schwassmann-Wachmann with the 1.2-m reflector at Mount Hopkins. The correction to the prediction by S. Nakano (MPC 48382; 2005 Comet Handbook) is -0.43 day. This component will pass only 0.08 AU from the earth on 2006 May 12. The brightness of this and the other two components at that time (if they have survived) is very uncertain and range from 2^m to 8^m. Orbital predictions for the components seen at previous returns by Z. Sekanina can be found in CBET 237, and the forthcoming October issue of the ICQ (27, 225). (IAUC 8623, subscription required, (CBET 237, subscription required)

2005 October 26

New Discovery!: John Broughton (Reedy Creek) reports his discovery of a new comet on Oct. 9, 2005. After posting on the NEO Confirmation Page several observers, including J. Young (Table Mountain), R. H. McNaught (Siding Spring), and J. E. McGaha (Tucson), were able to confirma the cometary nature of the 18^m object. Prediscovery observations by the Siding Spring Survey (Aug. 26, and Oct. 2) and by LINEAR (Sep. 26) were also identified. Comet P/2005 T5 (Broughton) will pass perihelion on Nov. 3, 2005, at about 3.2 AU. The period is about 19.5 years. This is the second amateur comet discovery of 2005, and the second in the current period for the Edgar Wilson Award. (IAUC 8621, subscription required, MPEC 2005-U53)
An apparently asteroidal object, discovered on Aug. 24, 2000, in the course of the LINEAR survey and designated 2000 QJ₄₆, has been reported to show a small coma and a short tail in images of the Sloan Digital Sky Survey of Sep. 3, and 4, 2000. Comet P/2000 QJ₄₆ (LINEAR) passed perihelion on Dec. 10, 2000, at about 1.9 AU. The period is about 14.4 years. This is LINEARs 163^th comet discovery. (IAUC 8622, subscription required)

2005 October 25

Reports with negative observations regarding the cometary nature of 2005 SD have been announced. C. Hergenrother (Mt. Graham 1.8-m VATT Lennon telescope and Mt. Hopkins 1.2-m reflector), R. Ferrando (Valencia), and J. Young and D. Mayes (Table Mountain) could not find any cometary activity. The object now no longer listed as a comet. (IAUC 8620, subscription required)

2005 October 23

New Discovery!: E. J. Christensen reports his discovery of a new comet on Oct. 22, 2005, in the course of the Catalina Sky Survey. After posting on the NEO Confirmation Page the 18^m comet was confirmed by R. H. McNaught (Siding Spring), P. Birtwhistle (Great Shefford), and by R. Miles (Stourton Caundle). The MPC was then able to detect several prediscovery observations including a two-night detection by the LONEOS survey of Sep. 11, 2005, which was then designated as 2005 RV₂₅. Comet P/2005 RV₂₅ (LONEOS-Christensen) will pass perihelion on Nov. 11, 2006, at about 3.6 AU. The period is about 9 years. This is the 35^th comet discovery by LONEOS and the 23^rd by Catalina. (CBET 262, MPEC 2005-U18)

2005 October 22

New Discovery!: R. D. Matson (Newport Coast) and M. Mattiazzo (Wallaroo) have independently reported the possible visibility of an unknown comet in the publicly available images of the SWAN instrument aboard the SOHO spacecraft from Oct. 6, to 13. Both estimated the object in the range 9-11^m. E. J. Christensen (Catalina Sky Survey) and R. H. McNaught (Siding Spring Survey) were then able to obtain confirmatory images. According to the first and very preliminary orbit comet C/2005 T4 (SWAN) passed perihelion on Oct. 2, 2005, at about 0.62 AU. According to this orbit the elongation will reduce further. The comet is an intrinsically faint object. (CBET 261, pers. comm.)

2005 October 17

An apparently asteroidal object discovered on Sep. 16, 2005, by the LINEAR survey and designated 2005 SD has been found to be cometary by R. Naves and M. Campas (Barcelona; Oct. 6.9 UT) and by T. Climent (Alginet, Oct. 15.9). The 17^m comet P/2005 SD (LINEAR) will pass perihelion on Nov. 16, 2005, at about 1.6 AU. The period is about 5.6 years. This is LINEARs 163^rd comet discovery. (IAUC 8618, subscription required, MPEC 2005-S17)

2005 October 11

New Discovery!: M. T. Read reported his discovery of a 20.5^m comet in the course of the Spacewatch survey. The very preliminary orbital elements with the help of Mt. Lemmon prediscovery observations of Sep. 30, 2005, for comet P/2005 T3 (Read) indicate perihelion already on Nov. 20, 2004, at about 5.9 AU. The period is about 23 years. This is the 30^th comet discovery by Spacewatch. (IAUC 8614, subscription required, MPEC 2005-T67)
New Discovery!: E. J. Christensen reported his discovery of a new comet in the course of the Mt. Lemmon survey. The 20^m comet P/2005 T2 (Christensen) passed perihelion on Mar. 18, 2005, at about 2.3 AU. The period is about 7.8 years. This is the 4^th comet discovery of the Mt. Lemmon survey. (IAUC 8614, subscription required, MPEC 2005-T66)

2005 October 09

E. J. Christensen reports the recovery of comet P/1993 W1 (= 1993s = 1994 XXV) on Oct. 07, 2005, in the course of the Mt. Lemmon Survey. Independently this comet was also recovered by M. E. Van Ness in the course of the LONEOS survey the same day. Later an independent recovery by F. Fratev (Plana) of Oct. 06, 2005, was also reported. The 18^m comet P/2005 T1 (Mueller) will pass perihelion on May 18, 2008, at about 4.21 AU. The period is about 13.6 years. The correction to the prediction in MPC 54168 is -0.8 day. (IAUC 8613, subscription required)

2005 October 08

Further SOHO comets: C/2005 P4 (SOHO) (T. Hoffman), C/2005 P5 (SOHO) (H. Su), C/2005 P6 (SOHO) (H. Su) and C/2005 Q5 (SOHO) (S. Farmer Jr.) are members of the Kreutz group. C/2005 Q6 (SOHO) (H. Su) belongs to no known comet group. Official SOHO comets: 1009. (MPEC 2005-T55)

2005 October 04

Two recently discovered comets turned out to be of short short period: P/2005 S2 (Skiff) will pass perihelion in 2008, at about 5.5 AU with period of about 19.8 years. The orbit is still quite uncertain. P/2004 S3 (Read) passes perihelion on Oct. 9, 2005, at about 2.9 AU with a period of about 11.5 years. (MPEC 2005-T26, MPEC 2005-T27)

2005 October 02

New Discovery!: R. H. McNaught (Australian National University) reports his discovery of new comet in the course of the Siding Spring Survey on Sep. 30, 2005. The 18.5^m comet C/2005 S4 (McNaught) could then be found in earlier images of this survey back to July 27, 2005. The orbit indicates perihelion on July 28, 2007, at about 5.9 AU. This is the 13^th comet discovery by the Siding Spring Survey and the 21^st comet that carries the name McNaught. (IAUC 8609, subscription required, MPEC 2005-T12)
New Discovery!: Michael T. Read reports his discovery of a new comet on Sep. 30, 2005, in the course of the Spacewatch survey. After posting the object on the NEO Confirmation Page several observers, including J. Lacruz (La Canada), P. Birtwhistle (Great Shefford), E. J. Christensen (Mt. Lemmon), J. E. McGaha (Tucson), and J. Young (Table Mountain), were able to confirm the cometary nature of the 18.5^m object. The first parabolic elements for comet C/2005 S3 (Read) indicate perihelion already on May 16, 2005, at about 2.4 AU. The comet is likely of short period. This is the 34^th comet discovery by Spacewatch. (IAUC 8608, subscription required, MPEC 2005-T11)