Astronomy:EE Pegasi
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 21h 40m 01.87850s[2] |
| Declination | +09° 11′ 05.1169″[2] |
| Apparent magnitude (V) | 6.96[3] (7.09 + 9.40)[4] |
| Characteristics | |
| A | |
| Spectral type | A3m[4] |
| B−V color index | 0.120±0.018[3] |
| B | |
| Spectral type | F5V[4] |
| B−V color index | 0.44±0.05[4] |
| Astrometry | |
| Radial velocity (Rv) | −22.6[5] km/s |
| Proper motion (μ) | RA: +41.237[2] mas/yr Dec.: +13.723[2] mas/yr |
| Parallax (π) | 6.9143 ± 0.0658[2] mas |
| Distance | 472 ± 4 ly (145 ± 1 pc) |
| Absolute magnitude (MV) | 0.50[3] |
| Orbit[4] | |
| Primary | AB |
| Companion | C |
| Period (P) | 2,628 d |
| Eccentricity (e) | 0.52±0.11 |
| Inclination (i) | 88.6[5]° |
| Periastron epoch (T) | 2,443,120±24 JD |
| Argument of periastron (ω) (secondary) | −85±11° |
| Semi-amplitude (K1) (primary) | 4.4±0.6 km/s |
| Details[4] | |
| A | |
| Mass | 2.15±0.02 M☉ |
| Radius | 2.09±0.03 R☉ |
| Luminosity | 53.42[3] L☉ |
| Surface gravity (log g) | 4.13±0.01 cgs |
| Rotational velocity (v sin i) | 40.0±1.0[6] km/s |
| Age | 300 Myr |
| B | |
| Mass | 1.33±0.01 M☉ |
| Radius | 1.31±0.01 R☉ |
| Surface gravity (log g) | 4.33±0.01 cgs |
| Rotational velocity (v sin i) | 26.0±2.0[6] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
EE Pegasi is a variable triple star system in the northern constellation Pegasus. It is too faint to be readily visible to the naked eye with a combined apparent visual magnitude of 6.96.[3] The system is located at a distance of approximately 472 light years from the Sun based on Parallax,[2] but is drifting closer with a radial velocity of −23 km/s.[5]
This system was found to be an eclipsing binary by German astronomer Cuno Hoffmeister in 1935, and has since been the subject of multiple studies. The pair orbit each other closely with a period of 2.628 days.[1][8] The magnitude 7.09 primary, component A, is an Am star with a stellar classification of A3m. It has more than double the mass and radius of the Sun. The secondary companion, component B, is an F-type main-sequence star with a class of F5V and a visual magnitude of 9.40. A third component is a smaller orange or red dwarf that orbits the main pair every 4.01 years.[4]
References
- ↑ 1.0 1.1 Ebbighausen, E. G. (June 1971). "The photometric elements of the eclipsing binary EE Pegasi". The Astronomical Journal 76: 460–464. doi:10.1086/111143. Bibcode: 1971AJ.....76..460E. https://ui.adsabs.harvard.edu/abs/1971AJ.....76..460E. Retrieved 11 February 2022.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Lacy, Claud H.; Popper, Daniel M. (1984). "Absolute dimensions and masses of eclipsing binaries. IV - EE Pegasi is a triple star". Astrophysical Journal 281 (1): 268–75. doi:10.1086/162096. Bibcode: 1984ApJ...281..268L.
- ↑ 5.0 5.1 5.2 "EE Pegasi Revisited: A Spectrum Synthesis and New Light Synthesis Study", Astrophysical Journal 459: 721, March 1996, doi:10.1086/176937, Bibcode: 1996ApJ...459..721L
- ↑ 6.0 6.1 Torres, G. et al. (February 2010). "Accurate masses and radii of normal stars: modern results and applications". The Astronomy and Astrophysics Review 18 (1–2): 67–126. doi:10.1007/s00159-009-0025-1. Bibcode: 2010A&ARv..18...67T.
- ↑ "EE Peg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=EE+Peg.
- ↑ "EE Peg". AAVSO. https://www.aavso.org/vsx/index.php?view=detail.top&oid=25271.
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