About HIP 172
HIP 172 is a rare star. It lies about 2,861 light-years from Earth, sits in the constellation Cep, shines at apparent magnitude 9.05 and has spectral type O7.
Its spectrum reads O7 — 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.