The Properties of X‐Ray and Optical Light Curves of X‐Ray Novae

We have collected the available data from the literature and from public data archives covering the past two decades for the long-term X-ray and optical light curves of X-ray nova (XN) outbursts. XN outbursts are due to episodic accretion events, primarily in low-mass X-ray binaries normally characterized by low mass transfer rates. Dynamical studies indicate that most XNs contain a black hole. The soft X-ray emission during outburst traces the accretion rate through the inner edge of the accretion disk, while the optical light curve traces the physical conditions at the outer diskthus, collectively, they contain information on the time-dependent behavior of accretion processes through the disks.