Seiichi Yoshida's Diary of Comet Observations (2003)

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Updated on May 9, 2006

Go to Seiichi Yoshida's Diary of Comet Observations in 2004.

2003 Dec. 14 (3 comets) I observed 3 comets visually on Dec. 14, the Geminids night, in Mt. Tsukuba, Ibaraki, Japan. C/2001 HT50 ( LINEAR-NEAT ) 11.3 mag   Dia. 1.1'   DC 5   (25.4-cm Schmidt-Cassegrain 128x) I felt it was very faint, fainter than 43P, and hard to see. So I imagined that it had finally faded out. However, my brightness estimation became equal to that on Dec. 2. So my impression was probably due to large moon that just rose from the east. C/2002 T7 ( LINEAR ) 9.2 mag   Dia. 2.5'   DC 7   Tail 4.5' (p.a. 85 deg)   (25.4-cm Schmidt-Cassegrain 32x) It has a tail, showing a hint of great comet. However my brightness estimation has been same for three weeks. 43P/Wolf-Harrington 12.4 mag   Dia. 0.9'   DC 4   (25.4-cm Schmidt-Cassegrain 128x) Faint, but already visible.

2003 Dec. 2 (2 comets) I observed 2 comets visually on Dec. 2 in Mt. Tsukuba, Ibaraki, Japan. C/2001 HT50 ( LINEAR-NEAT ) 11.3 mag   Dia. 1.1'   DC 5   (25.4-cm Schmidt-Cassegrain 128x) Close by half moon, but visible. However, the brightness and diameter might be underestimated due to moon light. C/2002 T7 ( LINEAR ) 9.2 mag   Dia. 1.4'   DC s6   Tail 6' (p.a. 100 deg)   (25.4-cm Schmidt-Cassegrain 67x) Very beautiful. Beautiful tail. Using lower magnification, the tail could not be visible, but I felt larger diameter.

2003 Nov. 21-22 (2 comets) I observed 2 comets visually on Nov. 21 and 22 in Mt. Tsukuba, Ibaraki, Japan. C/2001 HT50 ( LINEAR-NEAT ) Nov. 22   10.6 mag   Dia. 2.0'   DC 5   (25.4-cm Schmidt-Cassegrain 67x) Looks like a typical small faint comet. C/2002 T7 ( LINEAR ) Nov. 21   9.5 mag   Dia. 1.6'   DC 7-8   Tail ? deg   (25.4-cm Schmidt-Cassegrain 67x) Nov. 22   9.2 mag   Dia. 1.9'   DC 7   Tail ? deg   (25.4-cm Schmidt-Cassegrain 67x) Getting brighter and brighter. It is still strongly condensed. I felt it has a tail towards east.

2003 Oct. 29 (3 comets) I observed 3 comets visually on Oct. 29 in Mt. Tsukuba, Ibaraki, Japan. C/2001 HT50 ( LINEAR-NEAT ) 10.5 mag   Dia. 1.9'   DC 5-6   (25.4-cm Schmidt-Cassegrain 67x) It becomes more condensed and more easy to see. C/2002 T7 ( LINEAR ) 10.4 mag   Dia. 1.3'   DC 7   (25.4-cm Schmidt-Cassegrain 67x) It becomes much brighter than one month ago. Now it is around 10.5 mag. It is small. 2P/Encke fainter than 10.7 mag   Dia. 3'   (25.4-cm Schmidt-Cassegrain 67x) I could not see it. They say it is extremely diffused and hard to see.

2003 Sept. 27 (2 comets) I observed 2 comets visually on Sept. 27 in Happogahara, Tochigi, Japan. C/2001 HT50 ( LINEAR-NEAT ) 11.6 mag   Dia. 1.7'   DC 4   (25.4-cm Schmidt-Cassegrain 62x) Very faint, hard to see. C/2002 T7 ( LINEAR ) 11.7 mag   Dia. 1.3'   DC 6-7   (25.4-cm Schmidt-Cassegrain 133x) Very bright, easy to see.

2003 Sept. 22 (2 comets) I observed 2 comets visually on Sept. 22 in Mt. Tsukuba, Ibaraki, Japan. C/2001 HT50 ( LINEAR-NEAT ) 11.5 mag   Dia. 1.9'   DC 4   (25.4-cm Schmidt-Cassegrain 116x) It looked as before, widely diffused. C/2002 T7 ( LINEAR ) 11.5 mag   Dia. 0.8'   DC 7   Tail 1.2' (p.a. 260 deg)   (25.4-cm Schmidt-Cassegrain 116x) I was surprised that C/2002 T7 became much larger and brighter than in early September. Very strong condensation. Now it has a short tail towards west, although no recent CCD observations reported the tail.

2003 Sept. 4 (2 comets) I observed 2 comets visually on Sept. 4 in Kita-karuizawa, Gunma, Japan. C/2001 HT50 ( LINEAR-NEAT ) 11.4 mag   Dia. 1.4'   DC 4   (25.4-cm Schmidt-Cassegrain 116x) It looks similar to that in last winter, larger and more diffused than C/2002 T7. C/2002 T7 ( LINEAR ) 12.7 mag   Dia. 0.6'   DC 6   (25.4-cm Schmidt-Cassegrain 116x) Very small.