3 Equulei
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Equuleus |
| Right ascension | 21h 04m 34.65162s |
| Declination | +05° 30′ 10.3117″ |
| Apparent magnitude (V) | 5.593 |
| Characteristics | |
| Evolutionary stage | red giant branch |
| Spectral type | K5 III |
| U−B color index | +1.934 |
| B−V color index | +1.651 |
| Astrometry | |
| Radial velocity (Rv) | −15.26±0.2 km/s |
| Proper motion (μ) | RA: +13.115 mas/yr Dec.: +0.752 mas/yr |
| Parallax (π) | 2.6635±0.0940 mas |
| Distance | 1,220 ± 40 ly (380 ± 10 pc) |
| Absolute magnitude (MV) | −1.02 |
| Details | |
| Mass | 7.2 M☉ |
| Radius | 116 R☉ |
| Luminosity | 2,581 L☉ |
| Surface gravity (log g) | 1.06 cgs |
| Temperature | 4,029 K |
| Rotational velocity (v sin i) | 4.6 km/s |
| Other designations | |
| ζ Equ, 3 Equ, BD+04°4606, HD 200644, HIP 104031, HR 8066, SAO 126518 | |
| Database references | |
| SIMBAD | data |
3 Equulei is a single star located in the small northern constellation of Equuleus. It is faintly visible to the naked eye at an apparent visual magnitude of 5.6. Based upon an annual parallax shift of 2.7 mas, 3 Equulei is roughly 1,220 light-years (370 parsecs) distant from Earth, give or take a 40 light-year margin of error. At that distance, the apparent brightness of the star is diminished by 0.15 in visual magnitude because of extinction from interstellar gas and dust.
3 Equulei has been referred to in some sources as ζ (Zeta) Equulei, although it was not given that designation by Bayer.