Reports from Geisei Observatory<July 22, 2000>

• C/1999 S4(LINEAR)
At Geisei we had good weather for the first time in many days and LINEAR was clearly visible for about an hour in the evening sky. At 2:30 it was observed with the 20cm refractor at 60x. The magnitude (m1) was 6.2 and it had a tail of 30' - 60' in the north. It was still a binocular object and not clearly seen to the naked eye. The photograph was taken with an 8-minute exposure by the Metcalf guiding method by aligning the telescope to the comet. The comet was close to the earth and its motion was very fast.

2000U.T.        RA(2000)         decl.     m1
July 21.46761  9h22m19s.60  +58o34'04".4  6.2

The above position deviates from the latest orbit calculation by Mr. Okamura by about ±5" both in right ascension and declination. This is interpreted to be caused by non-gravitational forces.

C/1999 S4(LINEAR)
20:30 on July 22, 2000
8-minute exposure
60cm reflector at Geisei Observatory