Saiph
Blue supergiant · Kappa Orionis
Marks Orion's knee; far hotter than Betelgeuse yet looks fainter
Saiph marks the lower-left corner of Orion, the Hunter's right knee, and is a hot blue supergiant comparable in power to its famous neighbor Rigel. It looks noticeably fainter than its luminosity would suggest because so much of its energy pours out as invisible ultraviolet light.
Illustration generated from temperature, not a photograph
15.5 ☉
mass (the Sun = 1)
60 thousand ×
as bright as the Sun
25,700 K
surface · blue-white star
22 R☉
radius (the Sun = 1)
650 ly
from Earth
2.1
apparent magnitude
It pours out about 60 thousand times the Sun’s light. Its light has been travelling 650 years to reach us, so you see Saiph as it was 650 years ago.
Source · View on Wikidata
It lives in
Milky Way
Barred spiral galaxy.
Other notable stars in Milky Way
Eta CarinaeLuminous blue variableAlnilamBlue supergiantVY Canis MajorisRed hypergiantAlnitakHot blue supergiantDenebBlue-white supergiantMintakaHot blue giant multiple star
Stars of similar brightness
BetelgeuseRed supergiant60 thousand ×HV 2112Red supergiant (Thorne-Zytkow candidate)63 thousand ×AntaresRed supergiant76 thousand ×Sanduleak -69° 202Blue supergiant (B3 Ia)100 thousand ×HadarBlue giant32 thousand ×AcruxBlue subgiant (multiple system)31 thousand ×
Worlds in the same direction on the sky→