Taurus (constellation) is a white, spectral class B7 III giant star known as "El Nath", which comes from the Arabic phrase "the butting", as in butting by the horns of the bull. At magnitude 1.65, it is the second brightest star in the constellation, and shares the border with the neighboring constellation of Auriga. As a result, it also bears the designation Gamma Aurigae. Zeta Tauri (the proper name is "Tianguan") is an eclipsing binary star that completes an orbit every 133 days. A degree to the northwest of ζ Tauri is the Crab Nebula (M1), a supernova remnant. This expanding nebula
Vela (constellation) "Vel". The official constellation boundaries, as set by Eugène Delporte in 1930, are defined by a polygon of 14 segments. In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −37.16° and −57.17°. The brightest star in the constellation, Gamma Velorum, is a complex multiple star system. The brighter component, known as Gamma Velorum or Suhail, shines as a blue-white star of apparent magnitude 1.83. It is a spectroscopic binary made up of two very hot blue stars orbiting each other every 78.5 days and separated by somewhere