BL Lac天体ON231的CCD测光积分时间与测光误差分析  

Analysis of Integration Time and Photometric Error of the CCD Photometry for the BL Lac Object ON231

作　　者：邱光良[1] 张雄[1] 钱文枫 

机构地区：[1]云南师范大学物理与电子信息学院,云南昆明650092 [2]云南省民族中等专业学校,云南昆明650032

出　　处：《天文研究与技术》2013年第1期1-6,共6页Astronomical Research & Technology

基　　金：国家自然科学基金(11163007;U1231203)资助

摘　　要：积分时间对CCD测光结果的误差有很大影响。利用云南天文台1 m望远镜对BLLac天体ON231进行了I波段不同积分时间的观测,获得了I波段BL Lac天体ON231 CCD测光积分时间与测光误差的关系。结果表明,当BL Lac天体ON231处于低态时,在I波段的最佳积分时间约为294 s,此时测光误差最小。In the CCD photometry the integration time significantly affects the photometric error. We used the 1 m telescope of the Yunnan Observatory to observe the BL Lac object ON231 at the I band in different integration times, from 20s to 470s in an incrementing sequence with a lOs interval. All the images were reduced by using the CCDRED and APPHOT tasks in the IRAF software package, resulting in a total of 46 datapoints. We also analyzed the light curve of ON231 and found it in a low state with no variation during our observation time. We obtained the relations between integration time and photometric error of ON231 and two standard stars at the I band. We apply the polynomial fit to the relation of ON231, and calculate the optimal integration time （corresponding to the minimum photometric error）. The optimal integration time for ON231 at the low state at the I band is about 294s.

关 键 词：CCD测光 IRAF 积分时间 测光误差 

分 类 号：P12[天文地球—天体测量]