Astronomy:78 Pegasi
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 23h 43m 59.48560s[1] |
| Declination | 29° 21′ 41.2342″[1] |
| Apparent magnitude (V) | 4.93[2] (5.07 / 8.10)[3] |
| Characteristics | |
| Spectral type | K0III[4] |
| U−B color index | +0.63[5] |
| B−V color index | +0.96[5] |
| Astrometry | |
| Radial velocity (Rv) | −8.33[6] km/s |
| Proper motion (μ) | RA: +71.10[1] mas/yr Dec.: -40.58[1] mas/yr |
| Parallax (π) | 14.54 ± 0.56[1] mas |
| Distance | 224 ± 9 ly (69 ± 3 pc) |
| Absolute magnitude (MV) | 0.75[2] |
| Orbit[3] | |
| Period (P) | 630.15 yr |
| Semi-major axis (a) | 1.614″ |
| Eccentricity (e) | 0.112 |
| Inclination (i) | 60.64° |
| Longitude of the node (Ω) | 172.55° |
| Periastron epoch (T) | B 2247.71 |
| Argument of periastron (ω) (secondary) | 241.27° |
| Details | |
| 78 Peg A | |
| Mass | 1.50[7] M☉ |
| Radius | 10[7] R☉ |
| Luminosity | 57.35[2] L☉ |
| Surface gravity (log g) | 2.62[7] cgs |
| Temperature | 4,898[7] K |
| Metallicity [Fe/H] | +0.01[2] dex |
| Rotational velocity (v sin i) | 1.1[8] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
78 Pegasi is a binary star system in the northern constellation of Pegasus. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.93.[2] The system is located approximately 224 light years from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −8 km/s.[6] The double-star nature of this system was discovered by A. G. Clark in 1862. The components of this system orbit each other over a 630-year period with an eccentricity of 0.11.[10]
The primary member, designated component A, is a magnitude 5.07[3] giant star with a stellar classification of K0III,[4] having exhausted the supply of hydrogen at its core and expanded to 10[7] times the Sun's radius. It is a red clump giant,[11] which indicates it is on the horizontal branch and is generating energy through core helium fusion. It has 1.5[7] times the mass of the Sun and is radiating 57[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,898 K.[7] The secondary companion, component B, is magnitude 8.10.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. Vizier catalog entry
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. Vizier catalog entry
- ↑ 3.0 3.1 3.2 3.3 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6.
- ↑ 4.0 4.1 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.
- ↑ 5.0 5.1 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
- ↑ 6.0 6.1 Massarotti, Alessandro; Latham, David W.; Stefanik, Robert P.; Fogel, Jeffrey (2008). "Rotational and Radial Velocities for a Sample of 761 Hipparcos Giants and the Role of Binarity". The Astronomical Journal 135 (1): 209–231. doi:10.1088/0004-6256/135/1/209. Bibcode: 2008AJ....135..209M.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics 352: 555–562. Bibcode: 1999A&A...352..555A. Vizier catalog entry
- ↑ De Medeiros, J. R.; Mayor, M. (1999). "A catalog of rotational and radial velocities for evolved stars". Astronomy and Astrophysics Supplement Series 139 (3): 433. doi:10.1051/aas:1999401. Bibcode: 1999A&AS..139..433D. Vizier catalog entry
- ↑ "78 Peg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=78+Peg.
- ↑ Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics 546: A69. doi:10.1051/0004-6361/201219774. Bibcode: 2012A&A...546A..69M. Vizier catalog entry
- ↑ Tautvaišienė, G. et al. (December 2010), "C, N and O abundances in red clump stars of the Milky Way", Monthly Notices of the Royal Astronomical Society 409 (3): 1213–1219, doi:10.1111/j.1365-2966.2010.17381.x, Bibcode: 2010MNRAS.409.1213T.
 |  |
