2 Pegasi

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2 Pegasi
Pegasus constellation map.svg
Red circle.svg
Location of 2 Pegasi (circled)
Observation data
Epoch J2000       Equinox J2000
Constellation Pegasus
Right ascension 21h 29m 56.89545s [1]
Declination 23° 38′ 19.8170″ [1]
Apparent magnitude  (V)4.52 [2]
Characteristics
Evolutionary stage AGB [3]
Spectral type M1+III [4]
U−B color index +1.93 [5]
B−V color index +1.62 [5]
Astrometry
Radial velocity (Rv)−18.92 [6]  km/s
Proper motion (μ)RA: +24.74 [1]   mas/yr
Dec.: +3.63 [1]   mas/yr
Parallax (π)8.28 ± 0.18  mas [1]
Distance 394 ± 9  ly
(121 ± 3  pc)
Absolute magnitude  (MV)−0.89 [2]
Details
Radius 55 [7]   R☉
Luminosity 653 [7]   L☉
Temperature 3,919 [7]   K
Other designations
2 Peg, NSV  25624, BD+23°4325, FK5  1565, GC  30109, HD  204724, HIP  106140, HR  8225, SAO  89752, CCDM J21299+2338A, WDS J21299+2338A [8]
Database references
SIMBAD data

2 Pegasi is a single [9] star in the constellation Pegasus, located approximately 394 light years away from the Sun based on parallax. [1] It is visible to the naked eye as a faint, red-hued star with an apparent visual magnitude of 4.52. [2] The object is moving closer to the Earth with a heliocentric radial velocity of −19 km/s. [6] It has a magnitude 12.7 visual companion, designated component B, at an angular separation of 30.4″ . [10]

This is an aging red giant star with a stellar classification of M1+III, [4] currently on the asymptotic giant branch, [3] having exhausted the hydrogen at its core and evolved away from the main sequence. The star has expanded to an estimated 55 times the radius of the Sun. [7] It is radiating 653 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,919  K . [7]

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References

  1. 1 2 3 4 5 6 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID   18759600. Vizier catalog entry
  2. 1 2 3 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. Vizier catalog entry
  3. 1 2 Eggen, O. J. (1992), "Asymptotic giant branch stars near the sun", The Astronomical Journal, 104: 275, Bibcode:1992AJ....104..275E, doi:10.1086/116239.
  4. 1 2 Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
  5. 1 2 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M. Vizier catalog entry
  6. 1 2 Famaey, B.; Pourbaix, D.; Frankowski, A.; Van Eck, S.; Mayor, M.; Udry, S.; Jorissen, A. (2009). "Spectroscopic binaries among Hipparcos M giants". Astronomy and Astrophysics. 498 (2): 627. arXiv: 0901.0934 . Bibcode:2009A&A...498..627F. doi:10.1051/0004-6361/200810698. S2CID   18739721.
  7. 1 2 3 4 5 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.
  8. ↑ "2 Peg". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-04-07.
  9. ↑ 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.
  10. ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi: 10.1086/323920 . Vizier catalog entry
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