73 Orionis
Scientific overview
73 Orionis is a blue giant in the constellation Orion (Orionis), lying about 1,164.8 light-years from Earth.
Class B. Hot, blue-white stars. Massive and luminous, they often light up the regions where they form. Such stars have surface temperatures around 10,000–30,000 K and appear blue-white to the eye.
Physical properties
| Spectral type | B9II-III |
| Luminosity class | III |
| Apparent magnitude | 5.44 |
| Absolute magnitude | -2.32 |
| Luminosity (Sun = 1) | 741 |
| Colour index (B−V) | 0.015 |
| Distance | 1,164.8 ly (357.14 pc) |
Values are real catalogue data; fields without a reliable value are omitted, never estimated.
Precision measurements
Astrometry and astrophysics from SIMBAD
| Parallax | 2.343 ± 0.1597 mas | SIMBAD · measured |
| Proper motion (RA) | -1.512 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | -1.43 mas/yr | SIMBAD · measured |
| Radial velocity | 12.9 ± 1.2 km/s | SIMBAD · measured |
| Spectral type | B9II-III | SIMBAD · catalogued |
| Right ascension (ICRS) | 93.9374 deg | SIMBAD · measured |
| Declination (ICRS) | 12.5511 deg | SIMBAD · measured |
Full field-level provenance
- Parallax: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · plx_value · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Proper motion (RA): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Proper motion (Dec): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmdec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2007AN....328..889K · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · catalogue identifier/value · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
measured = direct catalogue value · estimated = Bayesian inference (Bailer-Jones distance) · modeled = model output (Gaia GSP-Phot). Fields a source did not provide are omitted, never invented.
Evolution
A blue giant is a hot, massive, highly luminous star that has evolved off the main sequence. Such stars are short-lived on cosmic timescales.
Location in the sky
Knowledge connections
- In constellationOrion
Related stars in Orion
Sources
The primary and reference sources this topic draws on.
- HYG DatabaseHYG Database (Hipparcos + Yale Bright Star + Gliese), by D. Nash / astronexus
Aggregated, openly-licensed star catalogue combining Hipparcos, the Yale Bright Star Catalogue, and the Gliese Catalogue of Nearby Stars.
- HipparcosESA Hipparcos space astrometry mission
High-precision parallax, magnitude, and position for ~118,000 stars.