Bellatrix is Gamma Orionis (γ Ori), HD 35468 and HIP 25336, permanent object 757. SIMBAD gives visual magnitude 1.64, a parallax of 12.92 ± 0.52 milliarcseconds and spectral type B2 III: https://simbad.cds.unistra.fr/simbad/sim-id?Ident=Bellatrix. Direct inversion of that parallax gives about 77 parsecs, or 252 light-years. That is an original scale calculation from the catalogue value, not an independent distance determination.
B2 marks a very hot blue star; luminosity class III labels a giant. Some research discussed Bellatrix as B2 V instead, illustrating that luminosity classification can differ when spectra and inferred absolute brightness do not fit a single simple label. The secure observational point is that Bellatrix is an early-B star much hotter and more luminous than the Sun. The eye sees an unresolved blue-white point, not a disk or a colour as saturated as a photograph.
Its most instructive uncertainty concerns membership, not subtype. A proposed “Bellatrix cluster” identified the star with the young 32 Orionis moving group because its sky position, roughly 77-parsec distance, proposed age and radial velocity all seemed similar. Bellatrix is also unusually nearby for such an early B star. Those coincidences made the association plausible.
Bell, Murphy and Mamajek tested the full three-dimensional motion. Bellatrix's proper motion produced a space velocity inconsistent with the group's mean by more than ten standard deviations in one component. They concluded that evidence was insufficient to include Bellatrix and advised against renaming the group after it. They left open the possibility that an unseen companion could perturb the measured motion, explicitly calling for more astrometry, spectroscopy and high-contrast imaging. Source: https://doi.org/10.1093/mnras/stx143.
This is a valuable example of how stellar membership is established. Similar distance, age and radial velocity are not enough; a co-moving group should share a consistent velocity vector after projection across the sky. The rejected name is not a failure but a refinement made possible by using all available dimensions.
Bellatrix means “female warrior” in Latin, a name that migrated from an older application to Orion's western shoulder star. The IAU standardizes Bellatrix for Gamma Orionis: https://www.iau.org/public/themes/naming_stars/. Gamma is the Bayer designation and does not itself state temperature, distance or group membership.
The stored position is approximately right ascension 5h 25m and declination +6° 21′. At latitude 45° N Bellatrix reaches about 51° altitude at upper culmination; at 35° S it reaches about 49°. These original geometric values ignore refraction, obstructions and whether culmination occurs in darkness.
To identify it, establish Orion's Belt, then trace northwest to the bright shoulder opposite Betelgeuse. In the repository's accepted figure, Bellatrix joins the upper body line and a line descending toward the Belt; checking both connections prevents confusion with nearby stars. The rendered finder and reader link still require separate review.
Bellatrix is an easy naked-eye target and gains no visible surface detail from a small telescope. Compare its cool-looking neighbour Betelgeuse and brilliant Rigel, but treat perceived colour as qualitative: altitude, adaptation and contrast alter the eye's response. Its permanent story is the hot star excluded from a tempting moving-group narrative; weekly Moon and timing stay in the almanac.
