Reports from Geisei Observatory <December 13, 2001>

• Photograph and observation data: C/2000 WM1 (LINEAR) moving out of sight
Soon LINEAR will set below the southern horizon. We've had the last glimpse of the comet from Geisei. The comet has brightened to the fifth magnitude and many reported that it was visible to the naked eye.

The following are visual observation data by Mr. Hirohisa Sato.

Comet C/2000 WM1(LINEAR)
2001/UT    m1   dia  DC   Tail   Trans.  Seeing  Instru.  Note
Dec. 4.46  5.7  11'  6      -     2/5     3/10   10x70B
Dec. 6.44  5.6  15'  5/     -     1/5     3/10   10x70B
Dec. 7.55  5.5  12'  5/    0.4°   3/5     6/10   10x70B    1
Dec. 9.43  5.4   8'  5/    0.3°   3/5     5/10   10x70B    2
Dec.10.43  5.3   9'  6      -     2/5     5/10   10x70B

  Note 1 P.A.38°
  Note 2 P.A.40°

The bright star in the photograph is SAO166103, a 5.6 magnitude star. Can you tell which is brighter, this star or the comet?

C/2000 WM1 (LINEAR)
19.00 on December 11, 2001
60cm reflector with a 15-minute exposure