百武彗星精密定位观测

Position Observations of Comet Hyakutake

１９９６年３月中旬，我们在观测海尔－波普彗星的同时，使用了云南天文台１ｍ镜加新研制的１０２４×１０２４ＣＣＤ照像机，对百武彗星也进行了照像观测。精密定位表明与最新的预报值仍有较大偏离。此时彗发已相当大，基本上轴对称。明显可见在对准太阳的相反方向有尾流物质喷出。但是我们发现，在短时间内，近核部分的尾向角就有变化。

On March 16 of 1996, we used a new developed 1024×1024 CCD camera attached to the 1 meter telescope at Yunnan Observatory, to take photometric observations for the Comet Hyakutake. The positions have been measured accurately. Our result clearly states that even a new ephemeris of the Comet Hyakutake just given by EMPC on February 29 of 1996 still has obvious larger systematical deviation with our observations. From images observed, we can clearly see that the cometary coma is very large and basicly symmetric with a peach shape. It means that there is material flowing along the cometary tail which opposited the solar direction.