Errai
Gamma Cephei
Scientific overview
Errai is a subgiant in the constellation Cepheus (Cephei), lying about 46 light-years from Earth.
Class K. Cooler orange stars. Long-lived and abundant; many are stable hosts for planets. Such stars have surface temperatures around 3,700–5,200 K and appear orange to the eye.
Physical properties
| Spectral type | K1IV |
| Luminosity class | IV |
| Apparent magnitude | 3.21 |
| Absolute magnitude | 2.46 |
| Luminosity (Sun = 1) | 9.003 |
| Colour index (B−V) | 1.031 |
| Distance | 46 ly (14.1 pc) |
Values are real catalogue data; fields without a reliable value are omitted, never estimated.
Precision measurements
Astrometry and astrophysics from SIMBAD
| Parallax | 72.5167 ± 0.147 mas | SIMBAD · measured |
| Proper motion (RA) | -64.86 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | 171.2 mas/yr | SIMBAD · measured |
| Radial velocity | -43.668 ± 2.000e-4 km/s | SIMBAD · measured |
| Spectral type | K1III-IVCN1 | SIMBAD · catalogued |
| Right ascension (ICRS) | 354.8 deg | SIMBAD · measured |
| Declination (ICRS) | 77.6324 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 · 2018A&A...616A...7S · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1989ApJS...71..245K · 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 subgiant has begun to evolve off the main sequence, brightening and expanding as core hydrogen fusion ends.
Location in the sky
Knowledge connections
- In constellationCepheus
Related stars in Cepheus
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.