12 Delphini
Scientific overview
12 Delphini is a hypergiant in the constellation Delphinus (Delphini), lying about 123.78 light-years from Earth.
Class A. White stars with strong hydrogen lines. Many of the brightest stars in the sky are class A. Such stars have surface temperatures around 7,500–10,000 K and appear white to the eye.
Physical properties
| Spectral type | A2Ia+... |
| Luminosity class | Ia+ |
| Apparent magnitude | 5.15 |
| Absolute magnitude | 2.25 |
| Luminosity (Sun = 1) | 10.924 |
| Colour index (B−V) | 0.495 |
| Distance | 123.78 ly (37.95 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 1763000482062205056
| Parallax | 27.8884 ± 0.0887 mas | SIMBAD · measured |
| Distance | 35.8256 pc | Gaia · estimated |
| Proper motion (RA) | -11.702 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | -204 mas/yr | SIMBAD · measured |
| Radial velocity | -6.97 ± 0.03 km/s | SIMBAD · measured |
| Spectral type | F8V | SIMBAD · catalogued |
| Effective temperature | 6164.7 K | Gaia · modeled |
| Radius | 2.6862 R_sun | Gaia · modeled |
| Surface gravity (log g) | 3.7452 log(cm/s^2) | Gaia · modeled |
| Metallicity [M/H] | -0.0359 dex | Gaia · modeled |
| Right ascension (ICRS) | 311.7 deg | SIMBAD · measured |
| Declination (ICRS) | 16.1241 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 1763000482062205056 · 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 · 2018A&A...615A..31D · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 1963ApJ...138..118S · catalogue identifier/value · retrieved 2026-07-11
- Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 1763000482062205056 · model output · retrieved 2026-07-11
- Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 1763000482062205056 · model output · retrieved 2026-07-11
- Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 1763000482062205056 · model output · retrieved 2026-07-11
- Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 1763000482062205056 · model output · 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 hypergiant is an exceptionally massive and luminous star, losing mass at a tremendous rate. Hypergiants are extraordinarily rare and short-lived.
Location in the sky
Knowledge connections
- In constellationDelphinus
Related stars in Delphinus
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.