Shaula

Shaula, second brightest star in the constellation Scorpius (after Antares) and the 24th brightest star in the sky. The star is found at the end of the tail in Scorpius, and its name may derive from al-shawlah, Arabic for “the scorpion’s sting.” Shaula has an apparent magnitude of 1.63 and is about 365 light-years from Earth. The star is a triple star system. The primary star is a hot blue star with a spectral type of B1.5, a mass 10.4 times that of the Sun, and a radius 5.2 times that of the Sun. The primary is a Beta Cephei variable; that is, its brightness changes slightly because of pulsations in the star’s atmosphere. A small young, pre-main-sequence star (that is, a star that has not started burning hydrogen in its core) with a mass 1.8 times that of the Sun orbits the primary every 6 days. The third star is also a hot blue star and has a spectral type of B2, a mass 8.1 times that of the Sun, and a radius 5.3 times that of the Sun. It orbits the primary with a period of about 1,000 days.