哈雷彗星1986年光谱的谱线证认

SPECTRAL LINE IDENTIFICATION OF HALLEY'S COMET IN 1986

1986年3—4月间,哈雷彗星的日心距为1和1.5 A.U.附近。我们使用云南天文台1米RCC望远镜和卡焦摄谱仪,取得了7张长狭缝光谱。这是我国唯一的一组哈雷彗星长狭缝光谱。光谱色散度为165(?)/mm,分辨率不小于7(?)。本文主要给出6张Kodak 103_a-O底片上3000—5100(?)波段的谱线证认结果。光谱片上主要出现了CN、C_2、C_3、CH、NH、OH等分子发射线,还可能存在NH_2、CH^+、N、H_2CO等发射线。光谱中连续辐射、吸收线较强,离子谱线少而弱,表明哈雷彗星是富尘的。OH(3090)发射线的出现既证实了卫星观测结果,又说明云南天文台的紫外观测条件是优越的。

In March-April of 1986, while Halley's Comet had heliocentric distances about 1 A. U. and 1.5 A. U., respectively, we made some long-slit spectral observations using the Cassegrain spectrograph attached to the 1-m RCC telescope of Yunnan Observatory. This paper is only concerned with the six nitrogen-baked Kodak 103a-O plates which have a spectral range of 3000-5100A with dispersion 165A/mm and a resolution no less than 7A. The dispersion curve of every plate is obtained by a polynomial fitting of wavelengths versus positions of a sequence of strong cometary emission lines. The result of spectral line identification makes clear that CN, C2, C3, CH, NH, OH exist in this comet, perhaps NH2, H2CO, CH+, N also exist. The fact of a number of strong absorption lines, strong continuum and very few ion lines suggests that Halley's Comet is dust-rich. The discovery of OH (3090) emission gives us a clue in the research of development of hydrogen cloud aroud this comet and indicates that the ultraviolet observations at Yunnan Observatory is in an excellent condition.