A Universal Decline Law of Classical Novae. III. GQ Mus 1983

We present a unified model of infrared (IR), optical, ultraviolet (UV), and X-ray light curves for the 1983 outburst of GQ Muscae (Nova Muscae 1983) and estimate its white dwarf (WD) mass. Based on an optically thick wind model of nova outbursts, we model the optical and IR light curves with free-free emission, and the UV 1455 \AA and supersoft X-ray light curves with blackbody emission. The best fit model that reproduces simultaneously the IR, optical, UV 1455 \AA, and supersoft X-ray observations is a 0.7 \pm 0.05 M_\sun WD for an assumed chemical composition of the envelope, X=0.35-0.55, X_{CNO} =0.2-0.35, and Z = 0.02, by mass weight. The mass lost by the wind is estimated to be \Delta M_{wind} \sim 2 \times 10^{-5} M_\sun. We provide a new determination of the reddening, E(B-V) = 0.55 \pm 0.05, and of the distance, \sim 5 kpc. Finally, we discuss the strong UV flash that took place on JD 2,445,499 (151 days after the outburst).