An international group of scientists has found a unique white dwarf star that was born from a cosmic collision. This is a significant finding that is redefining the way astronomers think about how stars evolve. WD 0525+526 is a unique star that is around 128 light-years away from Earth. It has a mass of about 1.2 solar masses, which is much greater than the ordinary white dwarf. On August 6, the journal Nature Astronomy released a study that went into great depth about the results.
When stars like our Sun run out of nuclear fuel and lose their outer layers, they become white dwarfs. Most of these stellar remnants are made when a single star slowly and gently fuses its own nuclear material together. But the past of WD 0525+526 was everything but kind. It is a remnant of a merger, which happened when two stars collided violently.
When you looked at WD 0525+526 in visible light, it looked like a fully normal white dwarf. Astronomers only found out its genuine, explosive genesis when they employed NASA’s Hubble Space Telescope’s sensitive ultraviolet equipment. The ultraviolet scans showed that there was a lot more carbon in the star’s atmosphere than expected. This was a key hint to its history.
The hydrogen and helium that make up a white dwarf’s atmosphere usually cover up the carbon in its core. The carbon on the surface shows that a major event in the past, such a merging of stars, removed a lot of these outer layers, leaving the carbon-rich core exposed. After its merger, WD 0525+526 has some strange traits for its class. It is not only very big, but it is also quite hot, with a surface temperature of about 21,000 Kelvin. All of this is packed into a body that is about the size of Earth.
This discovery has huge effects on how we think about how stars change over time. Astronomers think that many more white dwarfs with similar explosive origins could be “hiding in plain sight” because WD 0525+526 looked entirely normal in visible light.
Antoine Bédard, a researcher at the University of Warwick who co-led the study, said in a statement, “We would like to extend our research on this topic by exploring how common carbon white dwarfs are among similar white dwarfs and how many stellar mergers are hiding among the normal white dwarf family.” “That will help us learn more about white dwarf binaries and how they can explode into supernovae.”
The finding underlines the necessity of combining multi-wavelength observations, especially in the ultraviolet band, to unveil the hidden histories of celestial objects and better understand the dynamic and violent processes that build our universe.