Photometric Eclipses Detected and Orbital Period Determined for Cataclysmic Variable MASTER OT J232100.42+494614.0
What Was Observed (Empirical Data)
Photometric observations across two epochs separated by 12 months detected nine eclipses in the cataclysmic variable MASTER OT J232100.42+494614.0, establishing an orbital period of 0.212371533 ± 0.000000069 days (~5.1 hours) and an orbital inclination between 72.8° and 76.3°. Out-of-eclipse brightness varied between 15.61 ± 0.02 and 18.04 ± 0.05 mag, with eclipses averaging 1.36 ± 0.03 mag in depth and deepening as overall system brightness decreased. Combining these measurements with Zwicky Transient Facility (ZTF) survey light curves constrained the accretion disc's average absolute V-band magnitude to between 6.37 ± 0.35 and 6.68 ± 0.35 mag.
The Reality Check (Anti-Hype Analysis)
Despite exhibiting low-amplitude outbursts (< 2.5 mag) in ZTF survey data that are smaller than typical dwarf novae, the system's classification as a dwarf nova rests on calculated accretion disc brightness and mass transfer rates falling below the thermal instability threshold rather than direct spectroscopic confirmation. The orbital inclination and disc luminosity remain model-dependent range estimates derived from eclipse geometry. Furthermore, while the new baseline ephemeris enables future orbital period variation tracking, no period changes or third-body perturbations have been detected yet.
PRIMARY SOURCE:
arXiv Astrophysics (astro-ph)