HD 222093 is a double star in the equatorial constellation of Aquarius. It has an orange hue and is visible to the naked eye with an apparent visual magnitude of 5.68.[2] The system is located at a distance of approximately 293 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −13 km/s.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 37m 39.56021s[1] |
| Declination | −13° 03′ 36.8732″[1] |
| Apparent magnitude (V) | 5.68[2] + 9.6[3] or 11.19[4] |
| Characteristics | |
| Evolutionary stage | horizontal branch |
| Spectral type | K0III[5] |
| U−B color index | +0.81[2] |
| B−V color index | +0.99[2] |
| Astrometry | |
| Radial velocity (Rv) | −12.56±0.15[1] km/s |
| Proper motion (μ) | RA: +34.676[1] mas/yr Dec.: +26.758[1] mas/yr |
| Parallax (π) | 11.1185 ± 0.1442 mas[1] |
| Distance | 293 ± 4 ly (90 ± 1 pc) |
| Details | |
| Mass | 1.51[6] M☉ |
| Radius | 10.00+0.47 −1.06[1] R☉ |
| Luminosity | 50.0±0.8[1] L☉ |
| Surface gravity (log g) | 2.7[7] cgs |
| Temperature | 4,853+279 −110[1] K |
| Metallicity [Fe/H] | −0.25[7] dex |
| Rotational velocity (v sin i) | 0.0[7] km/s |
| Age | 3.17[6] Gyr |
| Other designations | |
| Database references | |
| HD 222093 | |
| SIMBAD | data |
| ADS 16878 | |
| SIMBAD | data |
The primary component is an aging K-type giant star with a stellar classification of K0III,[5] which indicates it has exhausted the supply of hydrogen at its core then cooled and expanded. At present it has ten[1] times the Sun's radius. This is a red clump giant,[9] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. It is around three billion years old with 1.5 times the mass of the Sun.[6] The star is radiating fifty times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,853 K.[1]
According to Eggleton and Tokovinin (2008), this is most likely a wide binary star system; the secondary companion is a magnitude 9.6 star at an angular separation of 33.1″ from the primary.[3] However, the Washington Visual Double Star Catalog gives a magnitude of 11.19 with an angular separation of 30.2″.[4]
References
edit- ^ a b c d e f g h i j k l Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ a b Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22.
- ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
- ^ a b c Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
- ^ a b c Massarotti, Alessandro; et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
- ^ "HD 222093". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-20.
- ^ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.