【摘要】 1978年初,我们在云南天文台的SBG人造卫星跟踪照相望远镜上,对类星体3C 273进行照相观测.初步建立起一套包括照相、测量、归算以及结果验核在内的照相测光方法. 本文报道了观测类星体3C 273的照相测光结果以及对疏散星团NGC 2287中部分恒星的测光.更多还原

【Abstract】 When the photographic image of a compact object (Seyfert galaxies, N galaxis, quasars and BL Lac. objects) or a star with nebulosity is composed of an extended area and its nucleus and an iris photometry is used to measure the image and to interpolate it in a series of comparison stars, the results of such a kind of photometry as to get its magnetude will be unreliable.In 1977, the first author of this paper observed an early type star with nebulosity photographically. Two series of plates were taken with different kinds and sizes of telecopes. These two series of plates with quite different I. t had been measured on an iris photometer. There were no significant differences between the two series of results. It was known that the images of the object were the illuminating star only with no extended area exposed on. The results of this observation had been published on Astronomic Circular No. 1 in April 1978.In 1980, the quasar 3C 273 was observed on an artificial satelite tracking camera telescope with an aperture 420/530 mm, and 788 mm focus installed at Yunnan Observatory. According to the above mentioned principle, we had worked out a method of photographic photometry for such type of celestial object, including photographing, measuring, reduction and checking in detail.As to acquire the fundamental photometric properties of the telescope SBG, the open cluster NGC 2287 had been observed in the first place. Then 3C 273 was observed with exposure times of 3 and 5 minutes on pairs of plates consecutively for measuring and reduction.On our iris photometer, two times at each star image and four different places surrounding the star image as its background were measured on each plates. The abnormal data of the background and the comparison stars Were rejected by Grubb’s method. There were three series of results worked out, i.e. with image readings minus background’s, and with background correction by Schaffer’s method and with Weaver’s method. These three series of results had been compaired with their errors and their consistency with Gaussian distribution, the best series then were chosen for final result.The photographic photometry of some stars of the open cluster NGC 2287 as well as the optical variations of the quasar 3C 273 observed in 1980 are presented in this paper.更多还原