Elnath
HIP 25428; Beta Tau; 112 Tau
Object Data
- Catalog Designation
- HIP 25428; Beta Tau; 112 Tau
- Type
- DoubleStar
- Constellation
- Tau
- Magnitude
- 1.65
- Right Ascension
- 05h 26m 17.5s
- Declination
- +28° 36' 27.0"
- Distance
- 134 light-years
- HR
- 1791
- HIP
- 25428
- Bayer
- Beta
Survey Image
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About Elnath
Description
Elnath (Beta Tauri) is the second brightest star in Taurus at magnitude 1.65, located about 134 light-years from Earth. It is a blue-white giant of spectral type B7III, about 4.5 times the mass of the Sun and 700 times more luminous. Elnath marks the tip of the northern horn of Taurus the Bull. It lies very close to the galactic anticenter — the point in the sky directly opposite the center of the Milky Way.
Observing Tips
Elnath is shared visually between Taurus and Auriga, sitting at the boundary where the Bull's horn meets the Charioteer's foot. It serves as a useful guide star — the supernova remnant M1 (Crab Nebula) lies about 1 degree to its northwest, and the open clusters of Auriga (M36, M37, M38) are nearby. Its blue-white color is evident to the naked eye. Best observed from November through March.
History
The name Elnath comes from the Arabic 'al-Natih' meaning 'the butting one,' referring to the tip of the bull's horn. Historically, the star was shared between the constellations Taurus and Auriga and carried the dual designation of Beta Tauri and Gamma Aurigae. In 1930, when the IAU formalized constellation boundaries, it was officially assigned to Taurus.
Fun Facts
Elnath is one of the few bright stars that was reassigned between constellations when modern boundaries were drawn. Its position near the galactic anticenter means that when you look at Elnath, you are looking outward through the disk of the Milky Way, away from the galactic center in Sagittarius.