Location of Gliese 251 in the constellation
Gemini
Gliese 251, also known as HIP 33226 or HD 265866, is a
star located about 18
light years away from the
Solar System. Located in the
constellation of
Gemini, it is the nearest star in this constellation.[10] It is located near the boundary with
Auriga, 49 arcminutes away from the bright star
Theta Geminorum; due to its
apparent magnitude of +9.89 it cannot be observed with the naked eye.[2] The closest star to Gliese 251 is
QY Aurigae, which is located 3.5
light years away.[11]
Gliese 251 is a
red dwarf with a
spectral type of M3V[3] with an effective temperature of about 3300
K.[3] Its mass has been measured to be around 0.36
solar masses[8] and its radius is about 36%
solar radii.[8] Its
metallicity is likely slightly less than that of the Sun.[8] Observations at infrared wavelengths rule out the presence of a circumstellar disk around it.[12]
Planetary system
In 2019, two candidate planets were detected by the
radial velocity method to orbit Gliese 251 at orbits of 1.74 and 607 days.[13] However, a new study in 2020 using
CARMENES data refuted both candidates, as they found that both signals were caused by stellar activity. Based on the CARMENES data, the team announced that Gliese 251 is orbited by one single
super-Earth (Gliese 251 b) at an orbit of 14.238 days.[8]
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abHøg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30.
Bibcode:
2000A&A...355L..27H.