New X-ray transients in the Mikhail Pavlinsky ART-XC all-sky survey

Resumo

We are used to look at the sky and observe well-known constellations and asterisms. New bright stars appear rarely. Once in a century a Supernova blazes up and several times in a year we see Novae, however, usually not that bright. And it is close to impossible to imagine that a known bright star would be extinguished. The reason is that the timescale for thermonuclear reactions inside the stars is large enough, about millions and billions of years, and during this time stars shine more or less stably.