Astronomy:Lambda Pegasi

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Short description: Fourth-magnitude star in the constellation Pegasus
λ Pegasi
Pegasus constellation map.svg
Red circle.svg
Location of λ Pegasi (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Pegasus
Right ascension  22h 46m 31.87786s[1]
Declination +23° 33′ 56.3561″[1]
Apparent magnitude (V) 3.93[2]
Characteristics
Spectral type G8II-III[3]
U−B color index +0.93[2]
B−V color index +1.07[2]
Astrometry
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]
Details
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
SIMBADdata

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 absolute magnitude 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.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 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. Bibcode2002yCat.2237....0D. 
  3. 3.0 3.1 3.2 3.3 3.4 Smith, G. (November 1998). "Stellar atmospheric parameters for the giant stars MU Pegasi and lambda Pegasi". Astronomy & Astrophysics 339: 531–536. Bibcode1998A&A...339..531S. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1998A%26A...339..531S&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf. 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 (1): 91–101. doi:10.1051/0004-6361:20078788. Bibcode2008A&A...480...91S. 
  5. 5.0 5.1 "λ Pegasi". Wolfram Alpha. http://www.wolframalpha.com/input/?i=lambda+pegasi. Retrieved 2012-08-28. 
  6. Kaler, James B.. "SADALBARI (Lambda and Mu Pegasi)". Stars. University of Illinois. http://stars.astro.illinois.edu/sow/sadalbari.html. Retrieved 2012-08-28. 
  7. 7.0 7.1 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. doi:10.1051/0004-6361/201118065. Bibcode2012A&A...538A.143K. 
  8. Hekker, S.; Meléndez, J. (December 2007). "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters". Astronomy and Astrophysics 475 (3): 1003–1009. doi:10.1051/0004-6361:20078233. Bibcode2007A&A...475.1003H.