What kind of star is Elnath?
Elnath, catalogued as Beta Tauri (β Tau), appears in the official constellation Taurus. Its apparent visual magnitude is 1.65, while its estimated distance is about 134 light-years. Astronomers classify the object as B7 III. These labels describe temperature, luminosity class or system components; they should not be read as a claim that every naked-eye point is a single isolated star.
Beta Tauri is a hot B-type giant or late main-sequence star with several solar masses and a photosphere much hotter than the Sun's. Spectroscopic abundance studies classify it among chemically peculiar mercury–manganese stars in some catalogues, where diffusion in a stable atmosphere produces element patterns unlike a simple solar mixture. Elnath lies toward the Galactic anticentre and close to the ecliptic, so the Moon can pass nearby and, from suitable locations, occult it. Its apparent position beside Auriga is purely angular. The formal Taurus–Auriga boundary establishes catalogue membership, but it does not mark a physical wall or imply that Elnath shares an origin with either constellation's other bright stars.
The coordinate pair RA 05h 26m 17.51s, Dec +28° 36′ 26.8″ fixes the object's direction on the celestial sphere for the J2000 reference epoch. Right ascension works like celestial longitude measured in hours, while declination works like latitude north or south of the celestial equator. Proper motion and improved measurements can refine catalogue positions, but these coordinates are sufficiently precise for a finder chart or planetarium search.
Elnath data at a glance
| Proper name | Elnath | Catalogue designation | Beta Tauri (β Tau) |
|---|---|---|---|
| Constellation | Taurus | Apparent magnitude | 1.65 |
| Spectral or system type | B7 III | Estimated distance | about 134 light-years |
| Right ascension (J2000) | 05h 26m 17.51s | Declination (J2000) | +28° 36′ 26.8″ |
Values are rounded for an observer-friendly overview. Consult the linked SIMBAD record for component-level identifiers, bibliography, measurement provenance and newer catalogue values.
The name Elnath
From Arabic al-naṭḥ, “the butting” or “the one that butts,” referring to the Bull’s horn.
The traditional Arabic name describes the Bull's act of butting and fits its placement at a horn tip. Bayer listed the same point as Beta Tauri and Gamma Aurigae because early constellation figures overlapped without universally fixed borders. When the International Astronomical Union adopted precise constellation boundaries in the twentieth century, the star fell on the Taurus side and Gamma Aurigae ceased to be a current designation. That change is a compact example of how official sky geography became non-overlapping.
Modern professional catalogues retain identifiers such as the Bayer designation alongside a proper name. The International Astronomical Union standardizes which name belongs to which component—an important distinction for systems whose combined light looks like one star from Earth.
How to find Elnath
Trace Taurus from Aldebaran through the Hyades toward the long northern horn. Elnath sits at its tip near Auriga, amid rich winter Milky Way fields visible in binoculars.
Best from northern and equatorial latitudes on winter evenings; also visible across much of the south. Visibility on a particular night still depends on latitude, season, time, horizon obstructions, weather and local light pollution. Use the interactive atlas below to check the surrounding field before observing.
Observation checklist
- Trace Taurus's long northern horn outward from the Hyades and Aldebaran.
- Use Capella and Auriga's pentagon as an alternative route from the north.
- Watch lunar calendars for close approaches because Elnath lies near the ecliptic.
- Binoculars give the best broad view of its boundary position between Taurus and Auriga.
Interesting facts about Elnath
- Elnath sits extremely close to the modern Taurus–Auriga boundary.
- It once also carried the designation Gamma Aurigae, but modern boundaries place it solely in Taurus.
- Elnath is Taurus’s second-brightest star after Aldebaran.
- It is a useful stepping stone between Taurus, Auriga and the winter Milky Way.
- Its hot blue-white light contrasts with orange Aldebaran.
Continue from Elnath into the night sky
Use the Taurus constellation guide to place this star within its larger pattern. When you are ready to observe, compare dark-sky places, find a nearby observatory, or follow our practical guide to finding a star in the night sky. Symbolically registered names are kept separately in the searchable Star-Register catalogue.
Sources and further reading
Measurements are rounded for readability. Multiple systems, variable stars and distant supergiants can have component-specific or model-dependent values. Survey panels show photographic sky fields, not the physical surface of the star.