Eta Pegasi

Eta Pegasi
Location of η Pegasi (circled) near the center
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pegasus
Right ascension 22h 43m 00.13743s[1]
Declination +30° 13′ 16.4822″[1]
Apparent magnitude (V) +2.95[2]
Characteristics
Spectral type G2 II + F0 V[3]
U−B color index +0.57[2]
B−V color index +0.86[2]
Astrometry
Radial velocity (Rv)+4.3[4] km/s
Proper motion (μ) RA: +13.16[1] mas/yr
Dec.: -25.67[1] mas/yr
Parallax (π)16.6308 ± 0.7047 mas[5]
Distance196 ± 8 ly
(60 ± 3 pc)
Absolute magnitude (MV)–1.18[6]
Orbit[7]
Period (P)813 days
Eccentricity (e)0.183
Periastron epoch (T)2452025 HJD
Argument of periastron (ω)
(secondary)		344.7°
Semi-amplitude (K1)
(primary)		14.37 km/s
Details
η Peg A
Mass3.51±0.13[8] M☉
Radius24.51+1.11
−1.21[8] R☉
Luminosity330.8±35.0[8] L☉
Surface gravity (log g)2.40[9] cgs
Temperature4970±65[8] K
Metallicity [Fe/H]+0.39[9] dex
Rotation818[6]
Rotational velocity (v sin i)1.4[7] km/s
Age0.27±0.03[8] Gyr
Other designations
Matar, Eta Peg, η Peg, 44 Peg, BD+29° 4741, FK5 857, HD 215182, HIP 112158, HR 8650, SAO 90734[10]
Database references
SIMBADdata

Eta Pegasi or η Pegasi, formally named Matar /ˈmeɪtɑːr/,[11][12] is a binary star in the constellation of Pegasus. The apparent visual magnitude of this star is +2.95,[2] making it the fifth-brightest member of Pegasus. Based upon parallax measurements, the distance to this star is about 214 light-years (66 parsecs) from the Sun.[1]

  1. ^ a b c d e Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference apjss119_1_83 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  5. ^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  6. ^ a b Cite error: The named reference aaa361_614 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference aj135_1_209 was invoked but never defined (see the help page).
  8. ^ a b c d e Cite error: The named reference Baines2018 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference aj110_2425 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
  12. ^ "IAU Catalog of Star Names". Retrieved 28 July 2016.