Researchers in the Theoretical Physics Group at Institute of Modern Physics, Chinese Academy of Sciences (IMP) have explored the effect of a strong magnetic field on the White Dwarf maximum mass.  

The Chandrasekhar mass limit plays a crucial role in modern astrophysics. If the mass of a white dwarf exceeds the Chandrasekhar limit, the degenerate electrons cannot support the star, and as a consequence, the star may collapse, leading to a type Ia supernova explosion. The type Ia supernovae can be used as standard candles to measure cosmic distance, and has led to the discovery that the Universe is undergoing an accelerated expansion. Some investigations indicated that strongly magnetized white dwarfs may violate the Chandrasekhar mass limit significantly, and thus one has to reconsider the expansion history of the Universe.   

However, these IMP studies show that, in order to keep the white dwarf stable, the magnetic field cannot be too strong. The estimated maximum mean magnetic field strength is ~10¹⁶ G which is too weak to change the mass limit distinctly. The conclusions are drawn as follows: 1) In a very strong magnetic field, the Lane-Emden formalism and its boundary condition may become invalid; 2) In a very strong magnetic field, the scaling behavior of the mass (and radius) with its central density  ( and ) becomes invalid; 3) The dynamical stability of a white dwarf categorically limits the role of the magnetic fields, requiring that the magnetic field cannot be too strong; 4) It is impossible that the super-Chandrasekhar white dwarf can be caused by strong magnetic field.   

The work has been published as a Comment in Phys.Rev.Lett. 112, 039001 (2014)