Astronomers using the Hubble Space Telescope have made a groundbreaking discovery, revealing that a white dwarf star may have originated from a violent cosmic collision. WD 0525+526, located about 128 light-years from Earth, was initially thought to be an ordinary white dwarf but further observations with Hubble’s ultraviolet instruments revealed signs of a dramatic past.
The star is believed to have formed from the merger of two stars, leaving behind subtle fingerprints in its atmospheric makeup. The detection of unusual amounts of carbon in the star’s atmosphere suggests that it was formed through this violent process. Normally, white dwarfs have outer layers of hydrogen and helium that obscure their carbon-rich cores. However, in mergers, the intense collision can strip away these layers, allowing carbon to rise to the surface.
Hubble excels at detecting such stars in ultraviolet wavelengths, which is why this discovery was possible. The star’s surface temperature is nearly 21,000 Kelvin (about 37,000 degrees Fahrenheit), making it hotter and more massive than other white dwarfs in its rare category.
This finding challenges our understanding of the formation process for white dwarfs and suggests that many more may have violent pasts. Researchers plan to explore how common carbon white dwarfs are among similar stars and how many stellar mergers are hiding among the normal white dwarf family.
The study, published in Nature Astronomy on August 6, provides new insights into the origins of these celestial objects and their role in supernova explosions.
Source: https://www.space.com/astronomy/hubble-space-telescope/hubble-telescope-uncovers-rare-star-born-from-cosmic-collision-a-very-different-history-from-what-we-would-have-guessed