HV 2112
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Tucana |
| Right ascension | 01h 10m 03.858s |
| Declination | −72° 36′ 52.62″ |
| Apparent magnitude (V) | 12.7 to below 16.7 |
| Characteristics | |
| Evolutionary stage | AGB |
| Spectral type | M5.5 II (M3e – M7.5) |
| Apparent magnitude (J) | 10.020 |
| Apparent magnitude (H) | 9.100 |
| Apparent magnitude (K) | 8.723 |
| U−B color index | +0.33 |
| B−V color index | +1.80 |
| Variable type | Mira? |
| Astrometry | |
| Radial velocity (Rv) | 157 km/s |
| Proper motion (μ) | RA: +1.038 mas/yr Dec.: −1.274 mas/yr |
| Parallax (π) | 0.0164±0.0246 mas |
| Absolute magnitude (MV) | −5.2 |
| Details | |
| Mass | ~5 M☉ |
| Radius | 675 - 1,193 R☉ |
| Luminosity | 50,100 - 81,300 L☉ |
| Surface gravity (log g) | 0.0 cgs |
| Temperature | 2,500 - 3,750 K |
| Metallicity [Fe/H] | −2.18 dex |
| Other designations | |
| HV 2112, 2MASS J01100385-7236526, SMC V2156, PMMR 187 | |
| Database references | |
| SIMBAD | data |
HV 2112 is a cool luminous variable star in the Small Magellanic Cloud. Until 2018, it was considered to be the most likely candidate for a Thorne–Żytkow object, but it is now thought to be an asymptotic giant branch star.