Short-Term Nongravitational Effect due to Nucleus Activity of Comet Hale-Bopp
HU Zhong-Wei, MA Jian-Bo, YANG Jie-Xing, WANG Qi (Department of Astronomy, Nanjing University, Nanjing 210098) (Purple Mountain Observatory, The Chinese Academy of Sciences, Nanjing 210008)
Whether an activity of comet's nucleus such as a jet can cause observable short-term nongrvitational effect? For several nucleus activities of Comet Hale-Bopp during late February-early April 1997, their astrometric data in the same period were analyzed. It is found that the deviations of the observed position from the calculated one according to the ephemeris are obviously more than the observational error as well as the offset of the nucleus mass-center from cometary light-center. Therefore, the results show that nucleus activities indeed can cause observable short-term nongravitational effect. The possible short-term variation of sun-comet distance due to the effect is estimated and the relation between the effect and corresponding activities is discussed.
【CateGory Index】： P134