鬼星团区域中部296颗AC星的自行测定

DETERMINATION OF THE PROPER MOTIONS OF 296 AC STARS IN THE CENTRAL PART OF THE PRAESEPE REGION

本文以复盖鬼星团区域的6张AC底片为第一期底片,1986年用佘山40厘米望远镜拍摄的7张鬼星团底片为第二期底片,作者在1991年发表的鬼星团中心区域257颗星的J2000.0位置和自行星表为参考星表,算出了296颗AC星的赤经自行和赤纬自行,精度好于±0”.005/年,大多数星达±0”.001/年左右。

Measurements for six plates in Astrographic Catalogue which overlay the Prae-sepe region are adopted as the first epoch positions. Seven second epoch plates were taken with the Zo-se 40 cm double astrograph in 1986. The reference stars are selected from the authors' catalogue in Acta Astronomica Sinica, Vol. 32(1991), p. 176. The proper motion components in R. A. and Dec. of 296 AC stars are determined, for which accuracies are higher than ±0'.005 yr-1 and mostly arrived at some ±0'.001