Astronomy:Phi Pegasi
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 23h 52m 29.28762s[2] |
| Declination | +19° 07′ 13.0218″[2] |
| Apparent magnitude (V) | 5.107[3] |
| Characteristics | |
| Evolutionary stage | red giant[4] |
| Spectral type | M2.5 IIIb[5] |
| U−B color index | +1.878[3] |
| B−V color index | +1.599[3] |
| Variable type | SRb[6] |
| Astrometry | |
| Radial velocity (Rv) | −7.75±0.15[7] km/s |
| Proper motion (μ) | RA: −7.27[2] mas/yr Dec.: −35.40[2] mas/yr |
| Parallax (π) | 7.05 ± 0.27[2] mas |
| Distance | 460 ± 20 ly (142 ± 5 pc) |
| Details | |
| Mass | 1.57[4] M☉ |
| Radius | 62.7[8] R☉ |
| Luminosity | 1,122[4] L☉ |
| Surface gravity (log g) | 0.81[8] cgs |
| Temperature | 3,600[4] K |
| Metallicity [Fe/H] | 0.0[4] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
φ Pegasi, Latinised as Phi Pegasi, is a solitary,[5] reddish hued star in the northern constellation of Pegasus. With an apparent visual magnitude of around 5.1,[3] it is a faint star that can be seen with the naked eye. Based upon an annual parallax shift of 7.05 mas as seen from Earth,[2] the system is located around 460 light years distant from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.15 due to interstellar dust.[7]
This is an evolved red giant star with a stellar classification of M2.5 IIIb.[5] It is a semiregular variable that ranges between magnitudes 5.11 and 5.17.[6] Hipparcos mission photometry gives an amplitude variation of 0.0148 in magnitude with a frequency of 11.4 cycles per day.[10] It is likely to be a semiregular variable and is tentatively classified as type SRb.[6]
In terms of its right ascension coordinates, φ Pegasi is located very near the line of the vernal equinox and will cross over around the year 3030, due to the precession of the Earth's axis.[11]
References
- ↑ "/ftp/cats/more/HIP/cdroms/cats". Strasbourg astronomical Data Center. https://cdsarc.cds.unistra.fr/viz-bin/ftp-index?/ftp/cats/more/HIP/cdroms/cats.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 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.
- ↑ 3.0 3.1 3.2 3.3 Gutierrez-Moreno, Adelina et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile (Publicaciones Universidad de Chile, Department de Astronomy) 1: 1–17, Bibcode: 1966PDAUC...1....1G.
- ↑ 4.0 4.1 4.2 4.3 4.4 Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R. et al. (2020), "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era", Astronomy and Astrophysics 633: A34, doi:10.1051/0004-6361/201936360, Bibcode: 2020A&A...633A..34C.
- ↑ 5.0 5.1 5.2 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ 6.0 6.1 6.2 Watson, Christopher (4 January 2010), "Phi Pegasi", AAVSO Website (American Association of Variable Star Observers), http://www.aavso.org/vsx/index.php?view=detail.top&oid=25523, retrieved 15 February 2014.
- ↑ 7.0 7.1 Famaey, B. et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics 430: 165–186, doi:10.1051/0004-6361:20041272, Bibcode: 2005A&A...430..165F.
- ↑ 8.0 8.1 McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society 471 (1): 770. doi:10.1093/mnras/stx1433. Bibcode: 2017MNRAS.471..770M.
- ↑ "phi Peg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=phi+Peg.
- ↑ Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society 331 (1): 45–59, doi:10.1046/j.1365-8711.2002.05150.x, Bibcode: 2002MNRAS.331...45K.
- ↑ Kaler, James B. (December 2, 2016), "PHI PEG (Phi Pegasi)", STARS (University of Illinois), http://stars.astro.illinois.edu/sow/phipeg.html, retrieved 2017-08-10.
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