K2-315

K2-315 is a star in the southern zodiac constellation Libra.[5] It has an apparent magnitude of 17.67,[3] requiring a powerful telescope to be seen. The star is relatively close at a distance of 185 light years[2] but is receding with a radial velocity of 6.25 km/s.[4]

K2-315

The location of K2-315 (circled in red)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Libra[1]
Right ascension	15h 12m 05.1944s[2]
Declination	−20° 06′ 30.5428″[2]
Apparent magnitude (V)	17.67[3]
Characteristics
Evolutionary stage	Red dwarf
Spectral type	M3.5±0.5 V[4]
Astrometry
Radial velocity (Rv)	6.25±0.17[4] km/s
Proper motion (μ)	RA: −120.013 mas/yr[2] Dec.: +74.471 mas/yr[2]
Parallax (π)	17.6353 ± 0.0492 mas[2]
Distance	184.9 ± 0.5 ly (56.7 ± 0.2 pc)
Details[4]
Mass	0.174±0.004 M☉
Radius	0.2±0.01 R☉
Luminosity	0.398% L☉
Surface gravity (log g)	5.094±0.006 cgs
Temperature	3,300±30 K
Metallicity [Fe/H]	−0.24±0.09 dex
Rotational velocity (v sin i)	<5 km/s
Age	>1 Gyr
Other designations
K2-315, EPIC 249631677
Database references
SIMBAD	data

K2-315 has a stellar classification of M3.5±0.5 V, indicating that it is a M-type main-sequence star (with 14% uncertainty).[4] It has 17.4% the mass of the Sun and 20% its radius.[4] Typical for red dwarves, it has a luminosity less than 1% of the Sun, which yields an effective temperature of 3,300 K.[4] Unlike most planetary hosts, K2-315 is metal-deficient, with an iron abundance only 57% that of the Sun.[4] It is estimated to be over a billion years old, and has a projected rotational velocity less than 5 km/s.[4]