3.35
Apparent Mag360
Distance (ly)M5Ib-II
Spectral Type3,300
Temperature (K)Rasalgethi is a red supergiant in Hercules and a semi-regular variable. It is one of the largest stars visible to the naked eye.
Stellar Data
Apparent Magnitude3.35
Absolute Magnitude-2.04
Distance360 light-years
Spectral TypeM5Ib-II
Temperature3,300 K
Luminosity17,000 L☉
Radius284 R☉
Mass2.175 M☉
Right Ascension17h 14m 38.9s
Declination+14° 23′ 25.2″
ConstellationHercules
Notable Facts
- Rasalgethi means the head of the kneeler in Arabic
- It is a semi-regular variable changing by about 1 magnitude
- The star is so large it would extend past the orbit of Mars