| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 23h 29m 28.8087s |
| Declination | +30° 25′ 57.849″ |
| Apparent magnitude (V) | +7.66 |
| Characteristics | |
| Spectral type | CEMP-r |
| Astrometry | |
| Radial velocity (Rv) | −121.16±0.12 km/s |
| Proper motion (μ) | RA: −16.583 mas/yr Dec.: −53.795 mas/yr |
| Parallax (π) | 1.8067 ± 0.0228 mas |
| Distance | 1,810 ± 20 ly (553 ± 7 pc) |
| Details | |
| Mass | 0.79±0.05 M☉ |
| Radius | 34.86±1.16 R☉ |
| Luminosity | 3,567±48 L☉ |
| Surface gravity (log g) | 1.252±0.042 cgs |
| Temperature | 4,248±128 K |
| Metallicity [Fe/H] | −2.40±0.13 dex |
| Other designations | |
HD 221170, HIP 115949, SAO 73293, BD +29° 4940, IRAS 23270+3009, TYC 2765-415-1, 2MASS J23292881+3025578 | |
HD 221170 is a very metal-poor red giant star in the constellation Pegasus, located 1,810 light-years from Earth. This star has a spectral type of CEMP-R. It has 76% the Sun's mass but, as a giant star, is 35 times wider and 3,600 times more luminous than the Sun, while its effective surface temperature is cooler, at 4,248 K (3,975 °C).
The name HD 221170 is because it is the 221,170th stars in the Henry Draper catalogue, however, the star does not have HR number, because it is too faint to visible by naked eye.
The name HIP 115949 is because it is the 115,949th star in the Hipparcos catalogue, and the name SAO 73293 is because it is the 73,293rd star in the Smithsonian Astrophysical Observatory Star catalogue.