HD 202259
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 14m 37.04896s |
| Declination | +00° 05′ 32.1202″ |
| Apparent magnitude (V) | 6.39 |
| Characteristics | |
| Evolutionary stage | AGB |
| Spectral type | M1 III |
| U−B color index | +1.937 |
| B−V color index | +1.608 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | −123.5 km/s |
| Proper motion (μ) | RA: +35.471 mas/yr Dec.: −13.260 mas/yr |
| Parallax (π) | 3.4472±0.0290 mas |
| Distance | 946 ± 8 ly (290 ± 2 pc) |
| Absolute magnitude (MV) | −0.88 |
| Details | |
| Mass | 1.9 M☉ |
| Radius | 50 R☉ |
| Luminosity | 693 L☉ |
| Surface gravity (log g) | 1.68 cgs |
| Temperature | 3,933 K |
| Metallicity [Fe/H] | −0.23 dex |
| Other designations | |
| BD−00°4186, HD 202259, HIP 104872, HR 8121, NSV 13614, SAO 145229. | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) | |
HD 202259 is a suspected variable star in the equatorial constellation of Aquarius. With an apparent magnitude of 6.39, according to the Bortle scale it is faintly visible to the naked eye from dark rural skies. It has a stellar classification of M1 III, and is a red giant located along the asymptotic giant branch of the HR diagram. Located about 946 light years away, its radial velocity of −123.5 km/s indicates this is a high-velocity star.