Elnath, Beta Tauri, HD 35497 and permanent object 758 are the same star. The repository preserves Hipparcos identifier 25428 and a position near right ascension 5h 26m and declination +28° 36′. SIMBAD lists visual magnitude 1.65, spectral type B7 III and parallax 24.36 ± 0.34 milliarcseconds. Inverting that parallax gives roughly 41 parsecs, or 134 light-years; the quoted uncertainty is only the formal parallax contribution. Source: [SIMBAD, Beta Tauri](https://simbad.u-strasbg.fr/simbad/sim-basic?Ident=bet+Tau).
The blue-white spectrum and luminosity class III describe a hot, evolved giant rather than a Sun-like main-sequence star. Elnath is also assigned to the mercury–manganese, or HgMn, class of chemically peculiar late-B stars. That label concerns the abundance pattern inferred from light emerging through the stellar atmosphere. It does not mean that the whole star is made of mercury and manganese in those proportions.
Adelman and collaborators measured abundances from high-resolution Dominion Astrophysical Observatory spectra. They found many of Beta Tauri's inferred abundances greater than those of another program star, Gamma Corvi, but did not detect the Hg II line at 3984 angstroms in Beta Tauri. A class name therefore does not guarantee that every namesake feature will be visible in every member. Diffusion, radiation pressure, gravity, rotation and atmospheric structure can separate elements in the thin layer whose spectrum observers measure; the paper constrains that visible layer, not the star's bulk recipe. Source: [Adelman et al., *Astronomy & Astrophysics* 447, 685–690](https://doi.org/10.1051/0004-6361:20053581).
The same analysis adopted a projected equatorial rotation speed of 59 kilometres per second. “Projected” is essential: spectroscopy measures rotation multiplied by the unknown inclination factor, so it supplies a lower limit rather than the true equatorial speed. Rotational broadening also makes weak abundance lines harder to isolate, another reason not to turn a non-detection into a claim that mercury is completely absent.
Its name is traditionally traced to Arabic for “the butting,” fitting the tip of the Bull's horn. The International Astronomical Union now standardizes Elnath as the proper name of Beta Tauri. Older atlases also treated the star as Gamma Aurigae because it sits where the Bull and Charioteer figures meet. Modern constellation boundaries place it in Taurus, while a drawn figure may still use it as an Auriga corner. Boundary membership and picture-making are different systems. Source: [IAU, Naming Stars](https://www.iau.org/public/themes/naming_stars/).
The stored declination makes Elnath a comfortable northern target. It culminates about 74° high from latitude 45° N and about 26° high from 35° S, before allowing for refraction or terrain. Those heights are original calculations from the preserved coordinates.
To find it, establish Aldebaran and the V-shaped Hyades, then follow Taurus's northern horn northeast to its bright endpoint. From Auriga, Elnath is the bright southern corner below Capella. Confirm the surrounding pattern rather than relying on either mythological picture alone. The repository's accepted geometry includes HIP 25428, but the rendered finder and reader link still require visual checking.
Elnath is easily naked-eye under ordinary skies. Binoculars emphasize its place between the two figures, while a small telescope shows a brilliant point, not atmospheric abundance patches or an enlarged stellar disk. Its blue-white colour can be compared with yellow Capella, but apparent colour depends on altitude, haze and eyesight. Record colour and field geometry separately, and leave changing Moon and darkness conditions to the weekly calendar.
