Campbell's Hydrogen Star
Scientific overview
Campbell's Hydrogen Star is a wolf-rayet star in the constellation Cygnus (Cygni).
Wolf-Rayet. Evolved, massive stars shedding their outer layers in powerful stellar winds. Such stars have surface temperatures around ≥ 30,000 K and appear blue to the eye.
Physical properties
| Spectral type | WC... |
| Apparent magnitude | 10 |
| Absolute magnitude | -10 |
| Luminosity (Sun = 1) | 870,964 |
| Colour index (B−V) | -0.013 |
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 2032744769234150016
| Parallax | 0.6184 ± 0.0324 mas | SIMBAD · measured |
| Distance | 1562 pc | Gaia · estimated |
| Proper motion (RA) | -2.251 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | -8.807 mas/yr | SIMBAD · measured |
| Radial velocity | -232.1 ± 2.894e-3 km/s | SIMBAD · measured |
| Spectral type | [WC9] | SIMBAD · catalogued |
| Right ascension (ICRS) | 293.7 deg | SIMBAD · measured |
| Declination (ICRS) | 30.5164 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
- Distance: ESA Gaia astrometric survey · Gaia EDR3 · Bailer-Jones (2021) · external.gaiaedr3_distance · r_med_geo · row 2032744769234150016 · Bayesian estimate · 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 · 2020AJ....160..120J · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 2003A&A...403..659A · 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 Wolf-Rayet star is a hot, evolved, massive star driving away its outer layers in fierce stellar winds, often a prelude to a supernova.
Location in the sky
Knowledge connections
- In constellationCygnus
Related stars in Cygnus
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.