Abstract Details

Name: Judhajeet Basu
Affiliation: Indian Institute of Astrophysics, Bangalore
Conference ID: ASI2025_147
Title: “Shock”-ing results from M31: Detailed analysis of the slow classical nova AT2023tkw (GIT20230919aa)
Authors: Judhajeet Basu (1, 2), Ravi Kumar (3), G.C. Anupama (1), Sudhanshu Barway (1), Peter H. Hauschildt (4), Shatakshi Chamoli (1, 2), Vishwajeet Swain (5), Varun Bhalero (5), Igor Andreoni (6), Kaustav K. Das (7), Viraj Karambelkar (7), Mansi Kasliwal (7), Avinash Singh (8), Rishabh Singh Teja (1, 2)
Authors Affiliation: (1) Indian Institute of Astrophysics, II Block, Koramangala, Bengaluru 560034, India (2) Pondicherry University, R.V. Nagar, Kalapet, Pondicherry 605014, India (3) Department of Aerospace Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India (4) Hamburger Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany (5) Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India (6) Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255, USA (7) Cahill Center for Astrophysics, California Institute of Technology, 1200 E. California Blvd. Pasadena, CA 91125, USA (8) Department of Astronomy, The Oskar Klein Center, Stockholm University, AlbaNova University Center, SE 106 91 Stockholm, Sweden
Mode of Presentation: Oral
Abstract Category: High Energy Phenomena, Fundamental Physics and Astronomy
Abstract: Novae are cataclysmic thermonuclear runaway explosions on the surface of white dwarfs accreting matter from a secondary star. Observable signatures include an increase in brightness up to several orders of magnitude across the UVOIR spectrum followed by a decline, characteristic of each nova. Recent studies have demonstrated the power of shocks in driving novae light curves. We present the slowly evolving classical nova in M31, AT 2023tkw, discovered and classified using optical facilities in India and the USA. The successive lightcurve peaks, occurring at increasing intervals, are likely due to a series of internal shocks generated near or within the photosphere. Through spectroscopic and photometric observations, we attribute the observed behavior to shock-induced heating events leading to the expansion and contraction of the photosphere, which led to multiple episodes of mass ejection (Basu et al., submitted). Photoionization models revealed a high ejecta mass, consistent with a slow nova. Eruption observations, together with HST archival data, helped identify the secondary star and shed light on the white dwarf characteristics, accretion properties, and recurrence timescales of the M31 nova.