HD 210056
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| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Octans |
| Right ascension | 22h 11m 54.98416s[1] |
| Declination | −76° 06′ 57.6788″[1] |
| Apparent magnitude (V) | 6.13±0.01[2] |
| Characteristics | |
| Spectral type | K0 III[3] |
| U−B color index | +0.82[4] |
| B−V color index | +1.00[4] |
| Astrometry | |
| Radial velocity (Rv) | 24±1[5] km/s |
| Proper motion (μ) | RA: −59.351 mas/yr[1] Dec.: −40.005 mas/yr[1] |
| Parallax (π) | 11.1656±0.0205 mas |
| Distance | 292.1 ± 0.5 ly (89.6 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.41[6] |
| Details[7] | |
| Mass | 1.59±0.07 M☉ |
| Radius | 7.72±0.13 R☉ |
| Luminosity | 29.7±0.5 L☉ |
| Surface gravity (log g) | 2.86±0.10 cgs |
| Temperature | 4,849±37 K |
| Metallicity [Fe/H] | −0.08±0.03 dex |
| Rotational velocity (v sin i) | <1.5[8] km/s |
| Age | 2.10±0.22[9] Gyr |
| Other designations | |
| 68 G. Octantis[10], CD−76°1120, CPD−76°1549, GC 31004, HD 210056, HIP 109584, HR 8432, SAO 258006[11] | |
| Database references | |
| SIMBAD | data |
HD 210056, also known as HR 8432, is a solitary orange hued star located in the southern circumpolar constellation Octans. Eggen (1993) listed it as a member of the old disk population.[12]
The object has an apparent magnitude of 6.13,[2] making it barely visible to the naked eye. Based on parallax measurements from the Gaia satellite, the object is estimated to be 292 light years distant.[1] It appears to be receding with a heliocentric radial velocity of 24 km/s.[5] At its current distance, HD 210056's brightness is diminished by 0.2 magnitudes due to interstellar dust. It has an absolute magnitude of +1.41.[13]
This is an evolved giant star with a stellar classification of K0 III. It has 1.59 times the mass of the Sun but has expanded to 7.72 times its girth.[7] It radiates 29.7 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,849 K.[7] Based on asteroseismologic measurements, HD 210056 is estimated to be 2 billion years old.[9] The star has about 90% of the Sun's metallicity — what astronomers define a star's abundance of chemical elements heavier than helium.[7] It currently spins slowly with a projected rotational velocity lower than 1.5 km/s.[9]
