Lambda Pegasi
Fourth-magnitude star in the constellation Pegasus
From Wikipedia, the free encyclopedia
Lambda Pegasi, also named Ligong,[8] is a fourth-magnitude star in the constellation Pegasus. It lies near Mu Pegasi, to the southwest of the brighter Beta Pegasi (Scheat).
 | |
| Observation data Epoch J2000 Equinox 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 mas[1] |
| Distance | 365 ± 10 ly (112 ± 3 pc) |
| Absolute magnitude (MV) | -1.45[5] |
| Details[6] | |
| Mass | 3.944±0.152 M☉ |
| Radius | 28.254±1.633 R☉ |
| Luminosity | 397±30 L☉ |
| Surface gravity (log g) | 2.12±0.08 cgs |
| Temperature | 4,848±109 K |
| Metallicity [Fe/H] | −0.07±0.06 dex |
| Rotational velocity (v sin i) | 8.0[7] km/s |
| Other designations | |
| Ligong, λ Peg, 47 Peg, BD+22°4709, FK5 859, GC 31776, GJ 4295, HD 215665, HIP 112440, HR 8667, SAO 90775, IRAS 22441+2318 | |
| Database references | |
| SIMBAD | data |
Nomenclature
Lambda Pegasi (Latinized from λ Pegasi, abbreviated λ Peg) is the star's Bayer designation. It traditionally shared the Arabic name Sadalbari with Mu Pegasi.[9]
In Chinese astronomy, this star is part of the constellation Ligong (離宮), representing a secondary or temporary palace. The IAU Working Group on Star Names adopted the name Ligong for this star on 13 August 2026, after this Chinese constellation.[8]
Properties
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.