Magnitude 3.96 Apparent magnitude (V) 3.96 | Constellation Pegasus | |
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Lambda Pegasi (λ Peg, λ Pegasi) is a fourth-magnitude star in the constellation Pegasus. It has the traditional name Sadalpheretz, sometimes spelled Sadalpheris or Sad Al Faris, from the Arabic سعد الفرس meaning "Luck of the Stallion", its etymology similar to that of the star Alpheratz, with both referring to the mythological winged-horse Pegasus.
Sadalpheretz 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☉. Its apparent magnitude was calibrated in 1983 at 3.96, yielding an intrinsic brightness of -1.45. Parallax calculations place the star at a distance of roughly 112 parsecs from Earth, or 365 ± 10 light years away, about three times the distance of its line-of-sight double Sadalbari.
In the constellation, Lambda and Mu lie to the southwest of Beta Pegasi, the nearest bright star.