A Serendipitous Observation of the Recently Discovered Cataclysmic Variable TUVO-21acq

Abstract

The recently discovered non-magnetic cataclysmic variable TUVO-21acq was serendipitously observed in a quiescent state during an XMM-Newton observing campaign for the starburst galaxy NGC 4945. Data from this campaign was combined with archival serendipitous XMM observations to examine its X-ray and UV/optical characteristics. TUVO-21acq was found to have X-ray flux F X(0.4–3.0 keV) ∼ 1.3 × 10−14 erg s−1 cm−2 and features similar to other quiescent dwarf novae, with X-ray luminosity L X(0.4–3.0 keV) ∼ 8 × 1030 erg s−1 and a white dwarf mass M WD = 0.78 − 0.27 + 0.37 M ⊙ . Its UV/optical spectrum was variable between observations, possibly due to changes in the accretion disk or the visibility of the bright spot.