Kappa Andromedae

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Kappa Andromedae, also known as Kaffalmusalsala, is a bright star in the northern constellation of Andromeda. It is visible to the naked eye with an apparent magnitude of about 4.1 and lies roughly 168 light-years away. The star is slowly moving closer to us and is likely part of the Beta Pictoris moving group.

Kappa Andromedae is a hot, young star weighing about 2.8 times the Sun’s mass. It is classified as a B9 subgiant (off the main sequence) and is spinning very fast, which makes it appear flattened at the poles. Its equatorial radius is about 2.30 solar radii, while the polar radius is about 1.96 solar radii. The surface temperature is hotter at the poles (around 12,050 K) and cooler at the equator (around 10,300 K), giving it a blue-white color. It shines with roughly 63 times the Sun’s luminosity. The star is young, with a best-estimated age of about 47 million years, though earlier studies gave a wide range.

In 2012, astronomers directly imaged a companion planet, Kappa Andromedae b, orbiting far from the star. The planet is about 13 times the mass of Jupiter, with a temperature around 1,700–2,150 K, and it follows a highly elongated orbit with a semimajor axis likely well over 75 AU.

Names tied to tradition include Kaffalmusalsala in Arabic astronomy, and in Chinese astronomy κ Andromedae is part of a larger asterism known as Flying Serpent, with its own name reflecting that system. In 2025, the IAU officially accepted the name Kaffalmusalsala for κ Andromedae.