双星与变星研究组知识库

Kepler K2 space telescope observations of cataclysmic variables (CVs) were used to search for periodic behavior and identify possible pseudo periods due to the satellite artefacts from periodic thrusters. Detailed period analyses were carried out for the dwarf nova UV Gem observed in the long cadence (LC) of the K2 campaign 0 (K2-C0) and seven CVs, comprised of four faint CVs and three known dwarf novae QZ Vir, RZ Leo and TW Vir observed in the long and short cadences (LC and SC) of the K2 campaign 1 (K2-C1), respectively. All 23 signals including harmonics and beat periods were identified from the periodograms of the four faint CVs in K2-C1. Among these 23 periods, there were eight signals distinctly detected from the periodogram of J1125-0016 due to a possible resonance between its orbital period and the common 5.9-hr satellite thruster period. A series of periodic dips with varying profiles obeying a period of 3.9256 day were found in all three SC light curves of K2-C1, which were extracted from the original K2 data files. This period is due to a periodic short-timescale resetting of the thruster. A two-dimensional power spectrum of the dwarf nova UV Gem observed in K2-C0 with a moving window of 4.7 day was derived for demonstrating the variations of the two significant modulations at the periods of 2.07 hr and 2.12 hr during the outburst and quiescent phases. In addition, the other two newly detected weak but consistent signals at the periods of 1.06hr and 0.91 hr were seen, likely due to the first harmonic of the 2.12 hr period and the fifth harmonic of the 6-hr thruster event of the satellite, respectively.