Misplaced Pages

2 Pegasi

Location of 2 Pegasi (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Pegasus
Right ascension	21 29 56.89545
Declination	23° 38′ 19.8170″
Apparent magnitude (V)	4.52
Characteristics
Evolutionary stage	AGB
Spectral type	M1+III
U−B color index	+1.93
B−V color index	+1.62
Astrometry
Radial velocity (Rv)	−18.92 km/s
Proper motion (μ)	RA: +24.74 mas/yr Dec.: +3.63 mas/yr
Parallax (π)	8.28 ± 0.18 mas
Distance	394 ± 9 ly (121 ± 3 pc)
Absolute magnitude (MV)	−0.89
Details
Radius	55 R☉
Luminosity	653 L☉
Temperature	3,919 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
Database references
SIMBAD	data

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

This is an aging red giant star with a stellar classification of M1+III, currently on the asymptotic giant branch, 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. It is radiating 653 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,919 K.

References

1. ^ 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. ^ 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. ^ 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. ^ 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. ^ 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. ^ 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. ^ 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

v t e Constellation of Pegasus
Pegasus in Chinese astronomy List of stars in Pegasus
Stars	Bayer α (Markab) β (Scheat) γ (Algenib) δ (Alpheratz) ε (Enif) ζ (Homam) η (Matar) θ (Biham) ι κ λ μ (Sadalbari) ν ξ ο π π ρ σ τ (Salm) υ (Alkarab) φ χ ψ Flamsteed 1 2 3 4 5 7 9 11 12 13 14 15 16 17 18 19 20 21 23 25 28 30 31 32 33 34 35 36 37 38 39 40 41 45 51 (Helvetios) 52 55 56 57 58 59 60 61 63 64 65 66 67 69 70 71 72 73 74 75 76 77 78 79 80 82 83 85 86 87 23 Psc 34 Vul Variable R S U W Z RU RV RZ SV TW TY AG AQ AT AU AV AW BB BH BK BO BP BX BY DH DI DY EE EF EQ EZ GT GX HN HO HP HR HX II IK IM IP KT KU LL LO LS MS MT NV NZ OY PT V342 V343 V354 V363 V372 V376 V391 HR 19 49 8116 8219 8221 8231 8250 8257 8258 8274 8292 8325 8341 8348 8358 8359 8364 8372 8391 8397 8412 8415 8435 8441 8455 8456 8458 8460 8461 8466 8475 8482 8491 8503 8514 8543 8555 8564 8587 8604 8605 8608 8631 8638 8642 8737 8784 8788 8792 8824 8831 8833 8838 8839 8873 8922 8942 8953 8970 9039 9055 9078 9109 HD 434 204603 205011 205422 205603 206689 206793 208897 209709 210890 211076 213025 215549 215733 219196 219828 220288 220773 221170 221493 225292 Other BD+14 4559 (Solaris) BD +17 4708 BD +28 4211 GD 246 Gl 829 Gl 880 HAT-P-8 NGC 8 NGC 18 NGC 30 PG 2131+066 PG 2303+243 PSR B2127+11C PSR B2303+30 Q2343-BX418 WASP-10 WASP-21 (Tangra) WASP-52 (Anadolu) WASP-59 WASP-60 (Morava) X2127+119 3C 454.3
Exoplanets 51 Pegasi b (Dimidium) WASP-10b BD+14 4559 b (Pirx) TOI-5678 b HD 209458 b HR 8799 b c d e
Star clusters	Other Balbinot 1 Messier 15
Nebulae	Other Pease 1
Galaxies	NGC 1 2 9 14 15 16 22 23 26 41 42 52 7033 7034 7042 7043 7053 7056 7066 7068 7074 7085 7190 7217 7236 7237 7303 7312 7315 7317 7318 7319 7320 7320c 7331 7332 7427 7448 7454 7457 7466 7469 7479 7610 7619 7625 7673 7674 7678 7720 7726 7735 7741 7742 NGC 7752 NGC 7753 7767 7769 7773 7800 7814 Other BX442 CTA-102 Einstein Cross Huchra's lens IC 5145 IC 5337 Markarian 335 Pegasus Dwarf Irregular Galaxy Pegasus Dwarf Spheroidal Galaxy Q2343-BX418
Galaxy clusters Abell 2390 NGC 7331 Group Stephan's Quintet
Astronomical events SN 1990U SN 2008ha SN 2013fs
Category

• M-type giants
• Suspected variables
• Pegasus (constellation)
• Durchmusterung objects
• Flamsteed objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects