Rigel (Beta Orionis)
Coordinates, Hipparcos distance (264 pc), luminosity (120,000 L☉), Rigel BC companion, and observing guide for Rigel in Orion.
Provenance-Backed Scientific Measurements
Every measurement below preserves its unit, uncertainty interval, observational method, reference epoch, quality status, and primary catalog source. See Uncertainty & Provenance for how competing measurements are handled.
| Parameter | Value | Uncertainty | Method & Epoch | Quality Status | Source Archive |
|---|---|---|---|---|---|
| Apparent visual magnitude (V) | 0.13 mag | 0.05 to 0.18 mag | Photoelectric V-band photometry (Alpha Cygni micro-pulsations) | definitive | Hipparcos New Reduction Catalog |
| Heliocentric distance | 264 pc | ± 24 pc | Hipparcos New Reduction parallax (3.78 ± 0.34 mas) (J2000.0) | high-confidence | Hipparcos New Reduction Catalog |
| Bolometric luminosity | 120000 L☉ | ± 25000 L☉ | VLTI interferometric angular diameter (2.75 mas) + UV/optical spectrophotometry | model-dependent | SIMBAD Astronomical Database (CDS) |
| Photospheric radius | 78.9 R☉ | ± 7.4 R☉ | VLTI/AMBER limb-darkened angular diameter at 264 pc | high-confidence | SIMBAD Astronomical Database (CDS) |
| Effective temperature | 12100 K | ± 150 K | Non-LTE B8 Ia quantitative spectroscopy | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots Rigel (Beta Orionis Blue Supergiant) at RA 05h 14m 32.27s, Dec -08° 12′ 05.9″ within Orion, alongside peak meridian transit altitudes for 40°N and 30°S observers. Use the RA/Dec Coordinate Converter to compute exact culmination altitude for your latitude.
Astrophysical Context & Structure
Rigel (Beta Orionis) is a dazzling B8 Ia blue-white supergiant marking the southwestern foot of Orion, and despite its 'Beta' Bayer designation it is almost always the brightest star in the constellation (magnitude 0.13 vs Betelgeuse's typical 0.4–0.6). Situated 264 ± 24 parsecs (860 light-years) away, Rigel is the most intrinsically luminous star among the night sky's ten brightest stars, radiating roughly 120,000 times the bolometric energy of the Sun.
Only 7 to 9 million years old, Rigel began life as an ~23-solar-mass O-type star, exhausted its core hydrogen, and recently evolved across the Hertzsprung-Russell diagram into a blue supergiant with a radius nearly 79 times that of the Sun (comparable to the orbit of Mercury). Non-radial pulsations across its photosphere cause subtle 0.05–0.18 magnitude brightness ripples over 1.2 to 74 days, accompanied by a powerful 10^-6 solar-mass-per-year stellar wind.
Rigel is the dominant member of a quadruple star system: 9.5 arcseconds south-southwest (>2,200 AU projected) orbits Rigel BC, a magnitude 6.7 visual companion that is itself a close binary of two B9 V main-sequence stars (Rigel Ba and Bb) orbited by a third B9 star (Rigel C). Rigel's intense blue light also illuminates the nearby Witch Head reflection nebula (IC 2118) 2.5° to the northwest.
Practical Visual Observing Guide
- Compare Rigel's icy 12,100 K blue-white brilliance at Orion's bottom-right corner directly against 3,600 K orange-red Betelgeuse at the top-left shoulder.
- Splitting 6.7-magnitude Rigel BC at 9.5 arcseconds separation from 0.13-magnitude Rigel A is a classic benchmark test for 60–80 mm refractors and 100–150 mm reflectors at 120×–180×.
- Ensure your optics are thermally equilibrated and well-collimated so Rigel B does not hide inside a diffraction spike or thermal plume.
Catalog Cross-Identifications & Aliases
Common Aliases: β Orionis · HD 34085 · HIP 24436 · 19 Orionis
| Catalog Authority | Identifier |
|---|---|
| HIP | HIP 24436 |
| HD | HD 34085 |
| SIMBAD | * bet Ori |
| WIKIDATA | Q12126 |
Related Objects, Comparisons & Guides
Betelgeuse (Alpha Orionis Red Supergiant)
Coordinates, competing optical vs radio distances (168 vs 222 pc), radius, Great Dimming physics, and observing guide for Betelgeuse.
Orion Nebula (Messier 42 / NGC 1976)
Coordinates, VLBI/Gaia distance (412 pc), Trapezium ionizing cluster, and visual observing guide for the Orion Nebula (M42) in Orion.
Sirius (Alpha Canis Majoris Binary)
Coordinates, Hipparcos parallax (379.21 mas, 8.60 ly), magnitude −1.46, Sirius B white dwarf orbit, and observing guide for Sirius.
Spica (Alpha Virginis Ellipsoidal Binary)
Coordinates, Hipparcos distance (250 ly), 4.01-day close B-star binary, precession discovery history, and observing guide for Spica.
Betelgeuse vs Rigel Supergiant Comparison
Compare Orion's two flagship supergiant stars—red supergiant Betelgeuse (Alpha Orionis) and blue supergiant Rigel (Beta Orionis)—in temperature, size, and mass.
Winter Circle, Orion & Taurus Observing Guide
Winter sky observing tour of Orion, Taurus, Canis Major, Auriga, and Perseus: bright OB/M supergiants, open clusters, M42, and the Crab Nebula (M1).
Splitting Bright Double & Multiple Stars Guide
How to resolve showcase binary and multiple star systems—Albireo, Mizar & Alcor, Epsilon Lyrae, Castor, and Sirius B—and test telescope Dawes limit.
Stellar Spectral Classification (OBAFGKM)
Reference guide to Morgan-Keenan (MK) stellar classification (O B A F G K M), luminosity classes (I–V, WD), color index (B-V), and the H-R diagram.
Apparent vs Absolute Magnitude Explained
Understand the logarithmic Pogson astronomical magnitude scale, apparent visual magnitude (m), absolute magnitude (M at 10 parsecs), and bolometric corrections.
Scientific Sources & Dataset Provenance
- Hipparcos New Reduction Catalog (2007 New Reduction): van Leeuwen, F. 2007, A&A, 474, 653 (Validation of the new Hipparcos reduction) — ESA / van Leeuwen (2007)
- IAU Working Group on Star Names (WGSN) (2026 IAU WGSN Bulletin): Mamajek, E., et al. (IAU WGSN) 2016–2026, IAU Catalog of Star Names — International Astronomical Union
- SIMBAD Astronomical Database (CDS) (2026-10 release): Wenger, M., et al. 2000, A&AS, 143, 9 (The SIMBAD astronomical database) — Centre de Données astronomiques de Strasbourg