New mass limit of white dwarfs

TL;DR

Recent observations of peculiar supernovae suggest super-Chandrasekhar white dwarfs exist, but their maximum mass is limited by magnetic and quantum effects, challenging previous assumptions and indicating a new mass limit.

Contribution

This paper introduces a theoretical framework incorporating magnetic flux freezing and Landau quantization to establish an upper mass limit for super-Chandrasekhar white dwarfs.

Findings

Super-Chandrasekhar white dwarfs cannot be arbitrarily massive.

Magnetic and quantum effects impose a new mass limit.

Paradigm shift in white dwarf mass understanding after 80 years.

Abstract

Is the Chandrasekhar mass limit for white dwarfs (WDs) set in stone? Not anymore -- recent observations of over-luminous, peculiar type Ia supernovae can be explained if significantly super-Chandrasekhar WDs exist as their progenitors, thus barring them to be used as cosmic distance indicators. However, there is no estimate of a mass limit for these super-Chandrasekhar WD candidates yet. Can they be arbitrarily large? In fact, the answer is no! We arrive at this revelation by exploiting the flux freezing theorem in observed, accreting, magnetized WDs, which brings in Landau quantization of the underlying electron degenerate gas. This essay presents the calculations which pave the way for the ultimate (significantly super-Chandrasekhar) mass limit of WDs, heralding a paradigm shift 80 years after Chandrasekhar's discovery.