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.
Related category NOTABLE STARS
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