About HD 15570
HD 15570 is a rare star. It lies about 2,104.2 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 8.13 and has spectral type O4....
Its spectrum reads O4... — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.