Stellar wraith

日期:2019-02-26 07:02:01 作者:风牲溱 阅读:

THE glowing ghosts of dead stars can haunt the heavens far longer than astronomers thought. A fuzzy patch in the northern sky is formed by the oldest known visible remains of a star that blew up in a supernova explosion. Russ Taylor of the University of Calgary, Canada, and his colleagues studied the faint shell-like gas cloud more than 40 000 light years away. From its distance and size, they concluded that it is stellar debris that has expanded into space following an explosion around a million years ago. Until now, astronomers thought supernova remnants faded and disappeared in only a fifth of that time. “There may be more of these things out there,