Lambda Pegasi

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λ Pegasi
Pegasus constellation map.svg
Red circle.svg
Location of λ Pegasi (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Pegasus
Right ascension  22h 46m 31.87786s[1]
Declination +23° 33′ 56.3561″[1]
Apparent magnitude (V) 3.93[2]
Spectral type G8II-III[3]
U−B color index +0.93[2]
B−V color index +1.07[2]
Radial velocity (Rv)-4.15[4] km/s
Proper motion (μ) RA: 55.75[1] mas/yr
Dec.: -10.15[1] mas/yr
Parallax (π)8.93 ± 0.24[1] mas
Distance365 ± 10 ly
(112 ± 3 pc)
Absolute magnitude (MV)-1.45[5]
Mass~1,5[3] M
Radius28.5[3][6] R
Luminosity390[3] L
Temperature4,933[7] K
Metallicity [Fe/H]0.12[7] dex
Rotational velocity (v sin i)8.0[8] km/s
Other designations
λ Peg, 47 Peg, HR 8667, BD +22 4709, HD 215665, FK5 859, HIP 112440, SAO 90775, GC 31776, IRAS 22441+2318, 2MASS J22463188+2333564
Database references

Coordinates: Sky map 22h 46m 31.9s, +23° 33′ 56.0″

Lambda Pegasi (λ Peg, λ Pegasi) is a fourth-magnitude star in the constellation Pegasus.

λ Pegasi is a yellow giant with stellar classification G8II-III. With a mass of 1.5 M and radius that is 28.5 R, the star boasts a bolometric luminosity that is roughly 390 L.[3] Its apparent magnitude was calibrated in 1983 at 3.96, yielding an intrinsic brightness of -1.45.[5] Parallax calculations place the star at a distance of roughly 112 parsecs from Earth, or 365 ± 10 light years away,[1] about three times the distance of its line-of-sight double μ Pegasi.

In the constellation, Lambda and Mu lie to the southwest of Beta Pegasi, the nearest bright star.


  1. ^ a b c d e f van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  2. ^ a b c Ducati, J. R (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ a b c d e Smith, G. (November 1998). "Stellar atmospheric parameters for the giant stars MU Pegasi and lambda Pegasi" (PDF). Astronomy & Astrophysics. 339: 531–536. Bibcode:1998A&A...339..531S. Retrieved 2012-08-28.
  4. ^ Soubiran, C; Bienaymé, O; Mishenina, T. V; Kovtyukh, V. V (2008). "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants". Astronomy and Astrophysics. 480: 91. arXiv:0712.1370. Bibcode:2008A&A...480...91S. doi:10.1051/0004-6361:20078788.
  5. ^ a b "λ Pegasi". Wolfram Alpha. Retrieved 2012-08-28.
  6. ^ Kaler, James B. "SADALBARI (Lambda and Mu Pegasi)". Stars. University of Illinois. Retrieved 2012-08-28.
  7. ^ a b Koleva, M.; Vazdekis, A. (February 2012). "Stellar population models in the UV. I. Characterisation of the New Generation Stellar Library". Astronomy & Astrophysics. 538, id.A143: A143. arXiv:1111.5449. Bibcode:2012A&A...538A.143K. doi:10.1051/0004-6361/201118065.
  8. ^ Hekker, S.; Meléndez, J. (December 2007). "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters". Astronomy and Astrophysics. 475 (3): 1003–1009. arXiv:0709.1145. Bibcode:2007A&A...475.1003H. doi:10.1051/0004-6361:20078233.