 |
|
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
| • HOME • ABOUT • CATEGORIES • COPYRIGHT • NEWSLETTER   
|
Rasalhague (Alpha Ophiuchi)
The brightest star in the constellation Ophiuchus; its name, which refers to the whole constellation, comes from an Arabic phrase meaning "the Head of the Serpent Collector." Rasalhague is a giant A star that has probably recently exhausted its core hydrogen reserves. It has a faint, very close companion only 0.5" away, equivalent to 7 AU in real terms, that orbits with a period of 8.7 years.
| visual magnitude | 2.08 |
| absolute magnitude | 1.30 |
| spectral type | A5III |
| surface temperature | 8,500 K |
| luminosity | 25 Lsun |
| mass | 2 to 4 Msun |
| distance | 47 light-years |
| position | R.A. 17h 34m 56.1s, Dec. +12° 33' 36" |
Related category
• NOTABLE STARSAlso on this site:
Encyclopedia of Alternative Energy & Sustainable Living
Encyclopedia of History