Nu Scorpii

Nu Scorpii (ν Scorpii, abbreviated Nu Sco, ν Sco) is a multiple star system in the constellation of Scorpius. It is most likely a septuple star system, consisting of two close groups (designated Nu Scorpii AB and CD) that are separated by 41 arcseconds. Based on parallax measurements, it is approximately 470 light-years from the Sun. The component Nu Scorpii Aa is formally named Jabbah /ˈdʒæbə/. Nu Scorpii is the system that causes the reflection nebula cataloged as IC 4592 and known as the Blue Horsehead nebula. Reflection nebulae are actually made up of very fine dust that normally appears dark but can look quite blue when reflecting the light of energetic nearby stars. Since it is near the ecliptic, Nu Scorpii can be occulted by the Moon and, very rarely, by planets. Mercury occulted it on 14 December 1821, but will not occult it again until 2 December 2031. The last occultation by Venus took place on 27 December 1852 and the next will take place on 30 December 2095. On 29 July 1808 there was an occultation by Neptune. ν Scorpii (Latinised to Nu Scorpii) is the system's Bayer designation.