News - August 2002
08/30/2002
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Three SOHO comets received orbits and designations: C/2002 Q6 (SOHO) is a
non-group comet found by X. Leprette, C/2002 Q7 (SOHO) is a Kreutz group
comet found by J. Sachs and C/2002 Q8 (SOHO) is the 9th member
of the Kracht group,
found by X.-M. Zhou. SOHO has now found 504 comets.
(MPEC 2002-Q46)
08/29/2002
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New Discovery!:
On Aug 28, 2002, the LINEAR project
discovered another new comet. After posting the object on the NEO Confirmation Page
several observers were able to confirm the cometary nature. The 15.5m
comet C/2002 Q5 (LINEAR) will pass perihelion according to the first and
preliminary orbit on Nov. 19, 2002, at about 1.2 AU. The comet won't become much
brighter since its decreasing distance to the Sun is countered by the increasing
distance to Earth. The elongation of this comet is steadily decreasing (below
35° in November and December). LINEAR has now found 92 comets.
(IAUC 7962,
MPEC 2002-Q43)
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Recovery!:
F. Artigue, H. Cucurullo, and G. Trancredi (Observatorio Astronomico Los Molinos,
Montevideo, Uruguay) report the recovery of comet P/1992 Q1 (= 1992p = 1992 XIV)
in the course of the
BUSCA program
(Búsqueda Uruguaya de Supernovas, Cometas y Asteroides). Comet P/2002 Q4 (Brewington)
makes its first observed return after its discovery apparition in 1992. The 16m
comet needed a correction to the prediction on MPC 40670 by +0.52 day. The comet is expected
to become as bright a 10m in early 2003.
(IAUC 7961,
MPEC 2002-Q41)
08/27/2002
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New Discovery!:
On Aug 26, 2002, the LINEAR project
reported the discovery of two new comets in the same field and moving with the same
apparent speed and direction. After posting the objects on the NEO Confirmation Page
several observers were able to confirm the cometary nature of both objects. Comets
C/2002 Q2 (LINEAR) and C/2002 Q3 (LINEAR) are indeed physically
connected as indicated by the preliminary orbital elements. The comets passed perihelion
around August 20, 2002, at about 1.3 AU. The first is described as being 17m
while the second seems to be 1-2m fainter. LINEAR has now found 91 comets.
(IAUC 7960,
MPEC 2002-Q37)
08/19/2002
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New Discovery!:
Michael E. Van Ness (Lowell Observatory) reports his discovery of a new comet in
the course of the LONEOS
program on Aug. 17, 2002. The first and preliminary orbit for the 16m
comet C/2002 Q1 (Van Ness) indicates perihelion on July 25, 2002, at about
1.65 AU. The comet will fade. This is the 19th new comet discovery by
LONEOS.
(IAUC 7956,
MPEC 2002-Q08)
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Z. Sekanina reports that he was able to link observations of the component A of comet
57P/du Toit-Neujmin-Delporte with its fragment F. The separation took place most
likely in the second half of May 2001, 400 days before perihelion at a distance of
about 3.6 AU. All attempts to confirm a separation at the 1996 apparition have
failed. The derived separation velocity is about 5 m/s. The predicted separation
distances and position angles (0h TT): 2002 Aug. 14, 401", 259.0 deg; 24,
398", 259.0 deg; Sept. 3, 393", 259.0 deg; 13, 387", 258.8 deg; 23,
383", 258.4 deg; Oct. 3, 381", 257.8 deg. Confirmation observations are
needed. (IAUC 7957)
08/17/2002
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The 501st SOHO comet was officially confirmed. C/2002 N2 (SOHO) is the 8th
member of the Kracht group
found by R. Kracht himself.
(MPEC 2002-Q02).
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Cometary science may have experienced a dramatic set-back when after a scheduled
orbital maneuver burn of the CONTOUR spacecraft on Aug 15, no contact to the spacecraft could be established.
Subsequent searches found two objects
moving on the same expected trajectories for the spacecraft so it seems possible
that it has broken into two pieces. More information about the ongoing events can
be found on the CONTOUR website. The
spacecraft was scheduled to visit the nuclei of comets 2P/Encke and
73P/Schwassmann-Wachmann 3.
08/15/2002
08/14/2002
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The 500th SOHO comet
belongs to the Meyer group and
is their 31st member. R. Kracht found comet C/2002 P3 (SOHO) in
real-time C2 images. This one is the first real-time comet of the new groups after
their recognition. R. Kracht may also found have the 8th member of the
Kracht group - but this is until
now not confirmed.
08/13/2002
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A SOHO Kreutz comet, found by R. Kracht, received the designation C/2002 P2 (SOHO).
This is SOHOs 499th discovery. Actually 500th SOHO comet has
already been found: Either an uncertain and weak archival Kreutz comet claimed by
D. Evans or a real-time Meyer group comet found by R. Kracht. No decision has yet
been made.
(MPEC 2002-P55)
08/12/2002
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A very unusual asteroidal object was found by W. K. Y. Yeung (Desert Wanderer Observatory)
and the NEAT program on Aug. 07, 2002. The
object moves in an extremely elliptical and short-period orbit with a small perihelion
distance of about 0.11 AU. The 2002 PD43 designated object has
an eccentricity of 0.958 and a period of about 4.2 years. No cometary activity of
this 17.5m object has been observed. This is the minor planet with the
second closest perihelion distance behind the Aten 2000 BD19.
Additionally it is a Potentionally Hazardous Asteroid (PHA) with a current possible
minimum distance to earth of about 0.035 AU.
(MPEC 2002-P51)
08/11/2002
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A first and very uncertain orbit for comet C/2002 P1 (NEAT) shows a very far
perihelion at about 7.1 AU already in July 2001.
(MPEC 2002-P46)
08/10/2002
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The 30th comet of the Meyer group
was found by R. Kracht. C/2002 H8 (SOHO) is the 498th comet
discovered by the SOHO spacecraft.
(MPEC 2002-P41)
- D. A. J. Seargent notes that according to a formula by J. Bortle (ICQ 79, July
1991) comet C/2002 O6 might not survive its perihelion. Bortle's formula
stated an empirical dependence of the survivability from the comets absolute
brightness and the perihelion distance. With an absolute brightness H(0) of about
10m and a perihelion distance q of about 0.5 AU this comet is right on
the borderline for survival. It may also be possible that comet C/2002 O6
experiences a rapid decrease in brightness following perihelion.
(Comet Mailing List)
08/08/2002
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New Discovery!:
S. Pravdo, K. Lawrence and E. Helin (JPL) report the discovery of a new comet on
August 07, 2002, in the course of the NEAT
program. G. Hug (Farpoint Observatory) was able to confirm the cometary nature of
this 18m object. Until now there is no orbit available for comet
2002 P1. A search ephemeris can be generated on the
NEO Confirmation Page.
This is NEATs 25th comet discovery. (IAUC 7950)
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H. Sato (Sukagawa, Fukushima, Japan) has prepared an
animation
of comet C/2002 O6 in SOHO/SWAN images. (e-mail)
08/06/2002
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Three SOHO comets received orbits and designations: C/2002 K8 (SOHO) and
C/2002 K9 (SOHO) were found by R. Matson, C/2002 K10 (SOHO) by D.
Evans. All three comets are members of the Kreutz group. SOHO has now found 497
comets. (MPEC 2002-P17)
08/05/2002
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New Discovery!:
On July 29, 2002, the LINEAR project
discovered an asteroidal object which showed cometary motion. After posting on the
NEO Confirmation Page A. Boattini (Campo Imperatore) and J. Ticha and M. Tichy
(Klet) noted a small coma. According to the first
and preliminary orbit the 17.5m comet C/2002 O7 (LINEAR) will
pass perihelion in September 2003, at about 0.8 AU. It may reach 6m but
then as an exclusive southern hemisphere object. This is LINEARs 89th
comet discovery. (IAUC 7949,
MPEC 2002-P13)
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New Discovery!:
On July 29, 2002, the NEAT program
discovered a new comet. After posting on the NEO Confirmation Page this object was
confirmed by A. C. Gilmore and P. M. Kilmartin (Mt John University Observatory).
Additional
pre-discovery images by Spacewatch (2001 May 22, June 11), LINEAR (2002 July 05) and
NEAT (2002 July 16) were found. The comet is of short-period and passed perihelion
already in May 2002, at about 3.2 AU. Its period is about 8.1 years. Interestingly
the 14m comet P/2002 O8 (NEAT) has a very low eccentricity (0.2).
This is NEATs 24th comet discovery. (IAUC 7949,
MPEC 2002-P14)
08/04/2002
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The first MPC orbit for comet C/2002 O6 confirms in general the previous
orbit. The orbital inclination is lower thus leading to even worse observing
conditions. From mid-European latitudes this comet will never climb higher than
about 15° in the morning sky. Latest visual brightness estimations place the
comet even at 7m making a maximum brightness of 6m in
mid-August possible.
(MPEC 2002-P10)
- 29P/Schwassmann-Wachmann is currently in outburst with about
12m as observed by L. Focardi (Italy) and P. Manteca (Spain).
(Comet Mailing List)
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Z. Sekanina (JPL) reports his preliminary analysis of the breakup circumstances of comet
57P/du Toit-Neujmin-Delporte by a method developed by him and P. Chodas.
The results show that component B could in fact have been broken off from the main
component at the last apparition in 1996 (when a brightness outburst was observed).
The origin of the other components is different: Components C-F were probably
produced more recently than B, and M-T may be fragments of B. A more complex
fragmentation hierarchy is possible. Additional astrometry is requested. More
information and offsets and position angles for component B can be found in IAUC
7946.
08/03/2002
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A very preliminary orbit for comet C/2002 O6 based on only 11 positions
was published by H. Sato. It
shows a perihelion on Sep. 09, 2002, at about 0.5 AU. This orbit indicates
a brightness maximum of maybe 6.5m in mid-August at the time of closest
approach to Earth with about 0.22 AU. Unfortunately from mid-European latitudes
this comet will be a difficult target low above the morning and beginning from
Aug. 21, above the evening horizon. Latest visual estimates by J. Drummond (New Zealand)
indicate a total visual brightness of about 8m while being well
condensed with a coma diameter of 6'.
(Comet Mailing List)
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Two SOHO comets received orbits and designations: C/2002 H7 (SOHO) and
C/2002 M8 (SOHO) were both found by D. Evans and are members of the Kreutz
group. SOHO has now found 494 new comets.
(MPEC 2002-P08)
08/02/2002
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A first and very preliminary orbit for comet P/2002 O5 (NEAT) shows this to
be a short periodic comet with a period of about 6 years. It passes perihelion on
August 2, 2002 (i.e. today) at about 1.2 AU. It becomes fainter.
(MPEC 2002-P06)
08/01/2002
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New Discovery!:
Another new comet was discovered by M. Suzuki on
publicly available images taken with the SWAN instrument aboard the SOHO spacecraft
on July 25 and 27, 2002. Prediscovery images reach back to July 13. The comet was
confirmed visually by A. Hale with about 9.5m. No orbit for comet
2002 O6 is yet available. A search ephemeris is available on the
NEO CP. The comet
is fast moving with about 4 degrees per day indicating that it is quite close to
Earth and very diffuse and extended. The elongation is decreasing thus making it a
difficult object to observe. This is SOHOs 493th comet discovery. (IAUC
7944)