标题： 昏暗食双星的观测 显示英文标题

标题： Observations of Faint Eclipsing Cataclysmic Variables

摘要： 我们展示了六个暗弱（V>17星等）激变变星（CVs）的时间分辨测光数据；其中一个是V849 Oph，其余的是从斯隆数字巡天（SDSS J0920+0042, SDSS J1327+6528, SDSS J1227+5139, SDSS J1607.02+3623, SDSS J1457+5148）中识别出来的。 这些目标的光学CCD测光观测是在2006年2月至2009年3月期间在土耳其的TÜBİTAK国家天文台进行的。 我们的目的是探测由热点调制、物质从红矮星快速转移到白矮星产生的闪烁结构以及选定的短周期（P<4h）激变变星在宁静状态下的轨道周期变化所引起的短时间尺度轨道变化。 对于每个系统，基于白矮星、吸积盘和热点的掩食定时和光变曲线形态的结果进行了讨论。 对SDSS J1227+5139的数据短时间覆盖分析表明，次级星上的磁活动引起了周期性变化。 本研究首次得出了SDSS J1607+3623的光周周期，而对于其他五个系统，则利用先前和新的测光观测修正了光元素。 SDSS J1457+5148的性质尚未被精确揭示，因为其光变曲线未显示出可能与轨道周期相关的周期性。 显示英文摘要

摘要： We present time-resolved photometry of six faint (V>17mag) cataclysmic variables (CVs); one of them is V849 Oph and the others are identified from the Sloan Digital Sky Survey (SDSS J0920+0042, SDSS J1327+6528, SDSS J1227+5139, SDSS J1607.02+3623, SDSS J1457+5148). The optical CCD photometric observations of these objects were performed at the T\"UB\.ITAK National Observatory (Turkey) between February 2006 and March 2009. We aimed to detect short time scale orbital variability arisen from hot-spot modulation, flickering structures which occur from rapid fluctuations of material transferring from red star to white dwarf and orbital period changes for selected short-period (P<4h) CVs at quiescence. Results obtained from eclipse timings and light curves morphology related to white dwarf stars, accretion disks and hot-spots are discussed for each system. Analysis of the short time coverage of data, obtained for SDSS J1227+5139 indicates a cyclical period change arisen from magnetic activity on the secondary star. Photometric period of SDSS J1607+3623 is derived firstly in this study, while for the other five systems light elements are corrected using the previous and new photometric observations. The nature of SDSS J1457+5148 is not precisely revealed that its light curve shows any periodicity that could be related to the orbital period.