Abstract Details
| Name: Shatakshi Chamoli Affiliation: Indian Institute of Astrophysics Conference ID: ASI2025_277 Title : Multiwavelength study of novae in M31 Authors and Co-Authors : Shatakshi Chamoli 1,2, Judhajeet Basu 1,2, Sudhanshu Barway 1, G.C. Anupama 1, Vishwajeet Swain 3, Harsh Kumar 3,4,5, Ravi Kumar 6, Varun Bhalerao 3, Dhananjay Raman 7, Aswin Suresh 8 Abstract Type : Oral Abstract Category : High Energy Phenomena, Fundamental Physics and Astronomy Abstract : Novae are a class of cataclysmic variables with an accreting White Dwarf (WD) primary and mass-transferring secondary star. These systems go into outburst as a consequence of thermonuclear runaway on the surface of the WD, leading to an increase in brightness. Novae with only one recorded outburst are called classical novae (CNe), while those with repeated outbursts are known as recurrent novae (RNe). Observations of novae in the Milky Way are biased due to our location and dust obscuration towards the centre. Hence we look to our neighbouring galaxies to study novae in different galactic components, such as spiral arms, bulge and halo. M31 is visible for most part of the year, suffers low extinction and has a higher nova rate than the Milky Way making it an excellent site for novae population studies. We present a multiwavelength study of novae in M31 using survey data from GROWTH-India Telescope (GIT) in the g’ and r’ filters and the AstroSat-UltraViolet Imaging Telescope (UVIT) in the F148W filter. Out of the 92 transients reported in the M31 field between July 2022 and December 2023, we detected 55 in the optical bands, and six close to outburst and 29 during quiescence in the UV. We analysed the multiwavelength light curves of these objects and filtered nova candidates based on their optical light curve morphology and increase in UV flux. We further categorised nova candidates into speed classes wherever possible and identified potential RNe based on the Maximum Magnitude vs Rate of Decline (MMRD) relation. We also report the 2024 outburst of the M31 RN with a recurrence period of 2.5 years, the second shortest known recurrence. |