Abstract: Novae offer key insights into stellar evolution and potential Type Ia supernova progenitors. We conduct an annual optical survey of M31 using the GROWTH-India Telescope (GIT), complemented by an analysis of archival AstroSat/UVIT FUV data. The UVIT survey revealed 42 novae, exhibiting both quiescent accretion disk signatures and outburst pseudo-photospheres, along with features such as pre-eruption dips and stable quiescent phases.
We highlight two extreme cases. The recurrent nova M31N 2008-12a shows jet-like outflows, ejecta masses of 10^{-7} - 10^{-8} M_sun , and anti-correlated UV–X-ray variability, indicating rapid accretion disk reformation. Recurrence analysis suggests a growing CO white dwarf above 1.36 M_sun . The classical nova AT 2023tkw, discovered by GIT, displayed multi-peaked light curves and spectral signatures of shock-driven photospheric expansion. Modeling points to a 0.65 M_sun white dwarf with a K giant companion and an ejecta mass of ~10{−4} M_sun
Early findings from LMC 1968-12a reveal a hot (~1 MK) white dwarf and a cooler (~20,000 K) UV component of uncertain origin. Together, these studies emphasize the importance of multiwavelength observations in understanding the diversity and evolution of novae.
