Hale-Bopp彗星的短期非引力效应与彗核活动

对于Hale-Bopp彗星在1997年2月底到4月初的几次彗核活动中，分析了它的同时期天体测量资料，发现它有活动时的观测位置与由彗星历表计算的位置偏差明显地超过观测误差，也超过彗星质心与光心的偏差。因此，这些结果表明彗核活动的确造成了可观测的短期非引力效应，对几次彗核活动及其相应的非引力效应作了讨论。

Short-Term Nongravitational Effect due to Nucleus Activity of Comet Hale-Bopp

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.