HD 8357
 A light curve for AR Piscium, plotted from TESS data,[1] the 12.345 day variability period[2] is shown in red. | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 01h 22m 56.757s[3] |
| Declination | +07° 25′ 09.33″[3] |
| Apparent magnitude (V) | 7.24[4] (7.68 + 8.43)[4] |
| Characteristics | |
| Primary | |
| Spectral type | Kl IV[4] |
| U−B color index | 0.68[4] |
| B−V color index | 0.93[4] |
| Variable type | RS CVn[5] |
| Secondary | |
| Spectral type | G7 V[4] |
| U−B color index | 0.29[4] |
| B−V color index | 0.71[4] |
| Astrometry | |
| Radial velocity (Rv) | 20.59±0.02[6] km/s |
| Proper motion (μ) | RA: 94.296 mas/yr[3] Dec.: 231.124 mas/yr[3] |
| Parallax (π) | 21.981 ± 0.0447 mas[3] |
| Distance | 148.4 ± 0.3 ly (45.49 ± 0.09 pc) |
| Absolute magnitude (MV) | 4.03[7] |
| Orbit[4] | |
| Period (P) | 14.30226±0.00010 d |
| Eccentricity (e) | 0.185±0.004 |
| Periastron epoch (T) | 2446079.950±0.051 JD |
| Semi-amplitude (K1) (primary) | 25.37±0.09 km/s |
| Semi-amplitude (K2) (secondary) | 31.01±0.18 km/s |
| Details | |
| Primary | |
| Mass | 1.12[4] M☉ |
| Surface gravity (log g) | 3.46±0.06[6] cgs |
| Temperature | 4,359±77[6] K |
| Metallicity [Fe/H] | −0.42[6] dex |
| Rotational velocity (v sin i) | 12[6] km/s |
| Age | 7−8[4] Gyr |
| Secondary | |
| Mass | 0.92[4] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
AR Piscium is a binary star system in the northern constellation of Canes Venatici, abbreviated AR Psc. It has the Henry Draper Catalogue identifier HD 8357; AR Piscium is its variable star designation.[9] The pair have a combined apparent visual magnitude that fluctuates around 7.24,[4] which is too faint to be readily visible to the naked eye. Parallax measurements place it at a distance of 148 light years from the Sun.[3] The motion of this star through the Milky Way suggests it is a member of the intermediate disc population.[4]
Variable X-ray source H0123+075 was identified from the HEAO 1 A-2 experiment and published by F. E. Marshall and associates in 1979. The following year, M. Garcia and associates identified the most probable source star as HD 8357, and determined it to be a RS Canum Venaticorum variable.[10] This has a spectral class of G5 in the Henry Draper Catalogue. Optical observations by D. S. Hall and associates in 1980–1981 confirmed the source star to be optically variable with a period of 12.3±0.1 d.[11] In 1993, AR Psc was identified as an extreme ultraviolet source by K. A. Pounds and associates using ROSAT.[12]
This is a double-lined spectroscopic binary with an orbital period of 14.3 days and an eccentricity of 0.185. The mass ratio of the two components is 1.222±0.008. The primary component is an evolving subgiant star with a stellar classification of Kl IV. It is the chromospherically active member of this system, displaying visual flares.[4] Intense X-ray flares have been detected.[13] The smaller and less massive secondary star is a G-type main-sequence star with a stellar class of G7 V. Based on the significant difference between the orbital and photometric periods, the two stars are in pseudosynchronous rotation.[4]
References
[edit]- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 27 September 2024.
- ^ "AR Psc". The International Variable Star Index. AAVSO. Retrieved 27 September 2024.
- ^ a b c d e 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 e f g h i j k l m n o p Fekel, Francis C. (July 1996), "Chromospherically Active Stars. XV. HD 8357=AR Piscium, an Extremely Active RS CVn System", Astronomical Journal, 112: 269, Bibcode:1996AJ....112..269F, doi:10.1086/118010.
- ^ Samus', N. N.; et al. (2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- ^ a b c d e Jönsson, Henrik; et al. (August 17, 2020), "APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South", The Astronomical Journal, 160 (3), American Astronomical Society: 120, arXiv:2007.05537, Bibcode:2020AJ....160..120J, doi:10.3847/1538-3881/aba592, ISSN 1538-3881, S2CID 220496397.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ "HD 8357". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-11-12.
- ^ Kholopov, P. N.; et al. (March 1985), "The 67th Name-List of Variable Stars", Information Bulletin on Variable Stars, 2681: 1, Bibcode:1985IBVS.2681....1K.
- ^ Garcia, M.; et al. (September 1980), "Optical identification of H 0123+07.5 and 4U 1137-65 : hard X-ray emission from RS CVn systems", Astrophysical Journal, 240: L107 – L110, Bibcode:1980ApJ...240L.107G, doi:10.1086/183334.
- ^ Hall, D. S.; et al. (June 1982), "Discovery of optical variability in the hard X-ray source HD 8357", Astrophysical Journal, 257: L91 – L92, Bibcode:1982ApJ...257L..91H, doi:10.1086/183815.
- ^ Pounds, K. A.; et al. (January 1993), "The ROSAT Wide Field Camera all-sky survey of extreme-ultraviolet sources. I. The bright source catalogue", Monthly Notices of the Royal Astronomical Society, 260: 77–102, Bibcode:1993MNRAS.260...77P, doi:10.1093/mnras/260.1.77.
- ^ Ambruster, C.; et al. (September 1984), "Intense X-ray flares from active stellar systems : EV Lacertae and HD8357", Astrophysical Journal, 284: 270–277, Bibcode:1984ApJ...284..270A, doi:10.1086/162405.
Further reading
[edit]- Karmakar, Subhajeet; et al. (January 2023), "Swift and XMM-Newton observations of an RS CVn-type eclipsing binary SZ Psc: superflare and coronal properties", Monthly Notices of the Royal Astronomical Society, 518 (1): 900–918, arXiv:2210.07170, Bibcode:2023MNRAS.518..900K, doi:10.1093/mnras/stac2970.
- Nakamura, Y.; et al. (July 2016), "MAXI/GSC detection of a possible X-ray flare from an RS CVn star AR Psc", The Astronomer's Telegram, 9288: 1, Bibcode:2016ATel.9288....1N.
- Sanz-Forcada, J.; et al. (October 2009), "No first ionization potential fractionation in the active stars AR Piscium and AY Ceti", Astronomy and Astrophysics, 505 (1): 299–306, Bibcode:2009A&A...505..299S, doi:10.1051/0004-6361/200912069.
- Shan, Hongguang; et al. (January 2006), "The atmospheric parameters, abundances and magnetic field of the AR piscium primary", New Astronomy, 11 (4): 287–292, Bibcode:2006NewA...11..287S, doi:10.1016/j.newast.2005.06.001.
- Montes, D.; et al. (1993), Linsky, Jeffrey L.; Serio, Salvatore (eds.), "Analysis of Chromospheric Activity Indicators in MM Her and AR Psc", Physics of Solar and Stellar Coronae: G. S. Vaiana Memorial Symposium, held 22-26 June, 1992, in Palermo, Italy, Astrophysics and Space Science Library, vol. 183, Dordrecht, The Netherlands: Kluwer Academoc Publishers, pp. 475–478, Bibcode:1993ASSL..183..475M, doi:10.1007/978-94-011-1964-1_69, ISBN 978-0-7923-2346-4.
