Aludra
Eta Canis Majoris
Scientific overview
Aludra is a blue supergiant in the constellation Canis Major (Canis Majoris), lying about 1,988.8 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 | B5Ia |
| Luminosity class | Ia |
| Apparent magnitude | 2.45 |
| Absolute magnitude | -6.48 |
| Luminosity (Sun = 1) | 33,916 |
| Colour index (B−V) | -0.083 |
| Distance | 1,988.8 ly (609.76 pc) |
Values are real catalogue data; fields without a reliable value are omitted, never estimated.
Precision measurements
Astrometry and astrophysics from SIMBAD and Gaia DR3 · Gaia DR3 5605797194566011520
| Parallax | 1.64 ± 0.4 mas | SIMBAD · measured |
| Proper motion (RA) | -4.14 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | 5.81 mas/yr | SIMBAD · measured |
| Radial velocity | 41.1 ± 2 km/s | SIMBAD · measured |
| Spectral type | B5Ia | SIMBAD · catalogued |
| Right ascension (ICRS) | 111 deg | SIMBAD · measured |
| Declination (ICRS) | -29.3031 deg | SIMBAD · measured |
Full field-level provenance
- Parallax: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · plx_value · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
- Proper motion (RA): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmra · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
- Proper motion (Dec): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmdec · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 1979IAUS...30...57E · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 2024A&A...690A.176N · catalogue identifier/value · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2007A&A...474..653V · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2007A&A...474..653V · 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 supergiant is among the most luminous stars known — enormous, hot, and massive. Many end their lives as supernovae.
Location in the sky
Knowledge connections
- In constellationCanis Major
Related stars in Canis Major
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.