About HD 49798
HD 49798 is a rare star. It lies about 2,718 light-years from Earth, sits in the constellation Pup, shines at apparent magnitude 8.28 and has spectral type O6.
Its spectrum reads O6 — 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.