Epsilon Pegasi

ε Pegasi
Location of ε Pegasi (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Pegasus
Right ascension 21h 44m 11.15614s[1]
Declination +09° 52′ 30.0311″[1]
Apparent magnitude (V) 2.399[1] (2.37 - 2.45)
Characteristics
Evolutionary stage Red supergiant
Spectral type K2 Ib-II[2]
U−B color index +1.722[3]
B−V color index +1.527[3]
Variable type LC[4]
Astrometry
Radial velocity (Rv)3.39 ± 0.06[5] km/s
Proper motion (μ) RA: +26.92[1] mas/yr
Dec.: +0.4[1] mas/yr
Parallax (π)4.73 ± 0.17 mas[1]
Distance690 ± 20 ly
(211 ± 8 pc)
Absolute magnitude (MV)–4.142[6]
Details
Mass7.07[7]–12[8] M
Radius178[9] – 211[7] R
Luminosity8,508[9] or 9,716 – 9,898[7] L
Luminosity (visual, LV)3,895[10] L
Surface gravity (log g)1.01[6] cgs
Temperature3,965[7] – 4,158[9] K
Metallicity [Fe/H]–0.04[6] dex
Rotational velocity (v sin i)8[11] km/s
Age20.0 ± 4.5[12] Myr
Other designations
Enif, 8 Pegasi, BD+09°4891, FK5 815, HD 206778, HIP 107315, HR 8308, SAO 127029[13]
Database references
SIMBADdata

Epsilon Pegasi (Latinised from ε Pegasi, abbreviated Epsilon Peg, ε Peg), formally named Enif /ˈnɪf/, is the brightest star in the northern constellation of Pegasus.

With an average apparent visual magnitude of 2.4,[3] this is a second-magnitude star that is readily visible to the naked eye. The distance to this star can be estimated using parallax measurements from the Hipparcos astrometry satellite,[14][15] yielding a value of around 690 light-years (210 parsecs).[1]

  1. ^ a b c d e f g Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
  3. ^ a b c Cite error: The named reference saaoc8_59 was invoked but never defined (see the help page).
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  6. ^ a b c Cite error: The named reference aaa480_1_91 was invoked but never defined (see the help page).
  7. ^ a b c d Stock, S.; Reffert, S.; Quirrenbach, A. (2018). "VizieR Online Data Catalog: Stellar parameters of 372 giant stars (Stock+, 2018)". VizieR On-line Data Catalog. 361. Bibcode:2018yCat..36160033S. doi:10.26093/cds/vizier.36160033.
  8. ^ Cite error: The named reference color was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference tycho-gaia was invoked but never defined (see the help page).
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  12. ^ Cite error: The named reference mnras410_1_190 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference aaa323_L49 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference GSM was invoked but never defined (see the help page).

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