This 2-faced white dwarf star defies astrophysical norms

tech.hindustantimes.com:

Behold Janus, a celestial enigma that defies conventional norms! Unlike the figurative phrase denoting two-facedness, this white dwarf star embodies the very essence of duality, quite literally. Drawing inspiration from the ancient Roman god, Janus, with one face gazing forward and the other backward, symbolizing transitions, this peculiar stellar remnant has earned its fitting moniker. Scientists have been captivated by the unique composition of Janus, as it bears an extraordinary feature - hydrogen dominates one side, while helium graces the other.

Janus, located about 1,300 light years from Earth in the direction of the Cygnus constellation, is fairly massive for a white dwarf. Its mass is 20% larger than that of our sun, compressed into an object with a diameter half that of Earth. Astonishingly, it rotates on its axis every 15 minutes, much faster than typical white dwarfs that take a few hours to a few days for a full rotation, according to a report by Reuters.

White dwarfs form at the end of a star's life, and Janus' peculiar composition raises intriguing questions about its evolutionary stage. The star might be transitioning from an atmosphere dominated by hydrogen to one dominated by helium, a process that usually involves a strong mixing of elements. Scientists speculate that Janus' magnetic field configuration could be the key to this asymmetry. If one side possesses a stronger magnetic field than the other, it could hinder the mixing of elements, leading to an uneven distribution of hydrogen and helium.

The discovery of Janus was made possible through the Zwicky Transient Facility at Caltech's Palomar Observatory near San Diego, followed by observations from other ground-based telescopes. This white dwarf may