Lambda Pegasi

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

λ Pegasi

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]
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 mas[1]
Distance	365 ± 10 ly (112 ± 3 pc)
Absolute magnitude (MV)	-1.45[5]
Details
Mass	~1,5[3] M☉
Radius	28.5[3][6] R☉
Luminosity	390[3] L☉
Temperature	4,933[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
SIMBAD	data

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. 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. S2CID 18759600.
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. Bibcode:2002yCat.2237....0D.
3. 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 (1): 91–101. arXiv:0712.1370. Bibcode:2008A&A...480...91S. doi:10.1051/0004-6361:20078788. S2CID 16602121.
5. "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. 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. S2CID 53999614.
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. S2CID 10436552.