Ultraviolet spark reveals comet-like tail to much-studied star

American astronomers have discovered a star with an usual comet-like glowing trail that they believe could provide vital clues about its history over the past 30,000 years.

The star, part of a double-star formation, Mira, is about 350 light years from Earth. The trail, a stunning 13 light years long, is only visible in ultraviolet light, they reported in Nature.