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arXiv · 2310.06586

Multi-wavelength observations of multiple eruptions of the recurrent nova M31N 2008-12a

Judhajeet Basu·M. Pavana·G. C. Anupama·Sudhanshu Barway·Kulinder Pal Singh·Vishwajeet Swain·Shubham Srivastav·Harsh Kumar·Varun Bhalero·L. S. Sonith·G. Selvakumar
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Abstract

We report the optical, UV, and soft X-ray observations of the $2017-2022$ eruptions of the recurrent nova M31N 2008-12a. We infer a steady decrease in the accretion rate over the years based on the inter-eruption recurrence period. We find a ``cusp'' feature in the $r'$ and $i'$ band light curves close to the peak, which could be associated to jets. Spectral modelling indicates a mass ejection of 10$^{-7}$ to 10$^{-8}$ M$_{\odot}$ during each eruption, and an enhanced Helium abundance of He/He$_{\odot}$ $\approx$ 3. The super-soft source (SSS) phase shows significant variability, which is anti-correlated to the UV emission, indicating a common origin. The variability could be due to the reformation of the accretion disk. A comparison of the accretion rate with different models on the $\rm M_{WD}$$-\dot{M}$ plane yields the mass of a CO WD, powering the ``H-shell flashes'' every $\sim$ 1 year to be $>1.36$ M$_{\odot}$ and growing with time, making M31N 2008-12a a strong candidate for the single degenerate scenario of Type Ia supernovae progenitor.

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Judhajeet Basu, M. Pavana, G. C. Anupama, Sudhanshu Barway, Kulinder Pal Singh, Vishwajeet Swain, Shubham Srivastav, Harsh Kumar, Varun Bhalero, L. S. Sonith, G. Selvakumar. 2023-10-10. Multi-wavelength observations of multiple eruptions of the recurrent nova M31N 2008-12a. https://doi.org/10.3847/1538-4357%2Fad2c8e

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