Astronomers have discovered an extremely cool object that could have a particularly diverse history—although it is now as cool as a planet, it may have spent much of its youth as hot as a star. The current temperature of the object is intermediate between that of the Earth and of Venus. However, the object shows evidence implying that a potentially large change in temperature has taken place. In the past this object would have been as hot as a star for many millions of years.
Explainers, News