哈勃望远镜揭示罕见恒星诞生于宇宙碰撞：“一个与我们猜测的截然不同的历史”

2025-08-18 新闻与动态

Astronomers using the have discovered that a seemingly ordinary white dwarf star is actually the result of a dramatic stellar merger..

This result, detailed in a new study led by Snehalata Sahu and Boris Gaensicke of the University of Warwick in the U.K., suggests that other "normal-looking" white dwarfs scattered throughout the universe could also have violent pasts.

"It's a discovery that underlines things may be different from what they appear to us at first glance," Gaensicke, study co-author and a professor of physics at the University of Warwick who serves as the principal investigator of the Hubble program, said in a . "Until now, this appeared as a normal white dwarf, but Hubble's ultraviolet vision revealed that it had a very different history from what we would have guessed."

A white dwarf merges with a red giant, creating a bow shock that strips its outer layers and exposes its carbon core. A new study reports that the white dwarf WD 0525+526 was likely formed through such a merger event, rather than through the normal life cycle of a single star. (Image credit: NASA, ESA, STScI, Ralf Crawford (STScI))

The star, named WD 0525+526, is located about 128 light-years from Earth. Though it appeared rather standard at first glance through visible light, further observations using the Hubble telescope revealed telltale signs of a more turbulent origin, the new study reports.

that have exhausted their fuel supplies and collapsed into Earth-size objects. Despite their small size, however, they can pack in up to 1.4 times the mass of the sun. Most white dwarfs form from the predictable evolution of single stars nearing the final days of their life cycles, which is a path our own sun is expected to follow in about 5 billion years.

However, WD 0525+526 may have followed a very different path. Instead of forming from one dying star, it appears to have and merger of two stars. This dramatic past, the new study says, left subtle but detectable fingerprints in the white dwarf's atmospheric makeup..

When Gaensicke and his team examined WD 0525+526 with Hubble's ultraviolet instruments, they detected an unusual amount of carbon in the star's atmosphere — a key sign the star was formed in a merger.