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
Cancer (constellation) as a lobster. Richard Allen, in "Star-names and Their Meanings", lists names for the constellation as follows: In Ancient Greece, Aratus called the crab "Καρκινος" ("Karkinos"), which was followed by Hipparchus and Ptolemy. The Alfonsine tables called it "Carcinus", a Latinized form of the Greek word. Eratosthenes extended this as "Καρκινος", "Ονοι", "και Φατνη" ("Karkinos", "Onoi", "kai Fatne"): the Crab, Asses, and Crib. In Ancient Rome, Manilius and Ovid called the constellation "Litoreus" (shore-inhabiting). "Astacus" and "Cammarus" appear in various classic writers, while it is called "Nepa" in Cicero's "De Finibus" and the works of Columella, Plautus, and Varro; all