Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Leo [1] |
Right ascension | 11h 29m 20.39171s [2] |
Declination | −01° 27′ 17.2817″ [2] |
Apparent magnitude (V) | 12.168±0.009 [3] |
Characteristics | |
Spectral type | M0V [4] |
B−V color index | 1.35 ± 0.06 [4] |
Astrometry | |
Radial velocity (Rv) | 30.24±0.46 [2] km/s |
Proper motion (μ) | RA: 94.116 mas/yr [2] Dec.: −78.003 mas/yr [2] |
Parallax (π) | 22.7374 ± 0.0220 mas [2] |
Distance | 143.4 ± 0.1 ly (43.98 ± 0.04 pc) |
Details [5] | |
Mass | 0.549+0.029 −0.027 M☉ |
Radius | 0.546+0.018 −0.016 R☉ |
Luminosity (bolometric) | 0.0587+0.0018 −0.0019 L☉ |
Surface gravity (log g) | 4.704+0.023 −0.026 cgs |
Temperature | 3844+61 −63 K |
Metallicity [Fe/H] | −0.157+0.075 −0.080 dex |
Rotation | 40±2 d [6] |
Age | 6.9±4.7 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
K2-3, also known as EPIC 201367065, [4] is a red dwarf star with three known planets. It is on the borderline of being a late orange dwarf/K-type star, but because of its temperature, it is classified as a red dwarf (4,000 K is typically the division line between spectral class M and K).
At a distance of 143 light-years (44 parsecs ), [2] the star's proximity means it is bright enough to make it feasible for astronomers to study the planets' atmospheres to determine whether they are like Earth's atmosphere and possibly conducive to life.
K2-3 has three confirmed exoplanets, discovered in 2015. [8] All are low-density super-Earths or sub-Neptunes, with the outermost orbiting near the inner edge of the habitable zone. [9] [5]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 5.11+0.65 −0.64 M🜨 | 0.0778±0.0026 | 10.054626(0) | <0.094 | 89.588+0.12 −0.100 ° | 2.078+0.076 −0.067 R🜨 |
c | 2.68±0.85 M🜨 | 0.1414±0.0047 | 24.646582(39) | <0.095 | 89.905+0.066 −0.088 ° | 1.582+0.057 −0.051 R🜨 |
d | <1.6 M🜨 | 0.2097±0.0070 | 44.556456(97) | <0.097 | 89.788+0.033 −0.029 ° | 1.458+0.056 −0.051 R🜨 |
GSC 02652-01324 is an orange dwarf main sequence star approximately 521 light-years away in the constellation of Lyra.
HD 101930, also known as Gliese 3683, is an orange hued star with an orbiting exoplanet located in the southern constellation Centaurus. It has an apparent magnitude of 8.21, making it faintly visible in binoculars but not to the naked eye. The system is located relatively close at a distance of 98 light years but is receding with a heliocentric radial velocity of 18.4 km/s. It has a relatively large proper motion, traversing the celestial sphere with an angular velocity of 0.320″·yr−1.
WASP-12 is a magnitude 11 yellow dwarf star located approximately 1347 light-years away in the constellation Auriga. WASP-12 has a mass and radius similar to the Sun and is known for being orbited by a planet that is extremely hot and has a retrograde orbit around WASP-12. WASP-12 forms a triple star system with two red dwarf companions. Both of them have spectral types of M3V and are only 38% and 37% as massive as the Sun, respectively.
WASP-4 is a G-type main-sequence star approximately 891 light-years away in the constellation of Phoenix. Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by a giant planet on a close orbit.
HAT-P-4 is a wide binary star consisting of a pair of G-type main-sequence stars in the constellation of Boötes. It is also designated BD+36°2593.
HAT-P-33 is a late-F dwarf star. It is orbited by a planet called HAT-P-33b. A search for a binary companion star using adaptive optics at the MMT Observatory was negative.
HD 106515 is a binary star in the constellation of Virgo.
Kepler-29 is a Sun-like star in the northern constellation of Cygnus. It is located at the celestial coordinates: Right Ascension 19h 53m 23.6020s, Declination +47° 29′ 28.436″. With an apparent visual magnitude of 15.456, this star is too faint to be seen with the naked eye. It is a solar analog, having a close mass, radius, and temperature as the Sun. Currently the age of the star has not been determined due to its 2780 light-year distance. As of 2016 no Jovian exoplanets of 0.9–1.4 MJ have been found at a distance of 5 AU.
Gliese 880 is a red dwarf star in the northern constellation of Pegasus that may host an exoplanetary companion. No stellar companions to Gliese 880 have been discovered as of 2020.
K2-3c, also known as EPIC 201367065 c, is an exoplanet orbiting the red dwarf star K2-3 every 24 days. It is 143 light-years away. It has a density of about 3.7 g/cm3, indicating that it could be an ocean world or a mini-Neptune. It is the second-smallest planet in the system by both radius and mass, with a mass almost three times that of Earth.
K2-3d, also known as EPIC 201367065 d, is a confirmed exoplanet of probable mini-Neptune type orbiting the red dwarf star K2-3, and the outermost of three such planets discovered in the system. It is located 143 light-years away from Earth in the constellation of Leo. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. It was the first planet in the Kepler "Second Light" mission to receive the letter "d" designation for a planet. Its discovery was announced in January 2015.
GJ 9827 is a star in the constellation of Pisces. It is a K-type main-sequence star with an apparent magnitude of 10.250. It is 97 light-years away, based on parallax.
K2-19 is an early K-type or late G-type main sequence star that is magnetically active, and has a light curve that exhibits variations in brightness of ~1%. It is located approximately 976 light-years away in the constellation Virgo. Three confirmed transiting exoplanets are known to orbit this star.
K2-18, also known as EPIC 201912552, is a red dwarf star with two planetary companions located 124 light-years from Earth, in the constellation of Leo.
K2-24 is a metal-rich G3-type main sequence star larger and more massive than the Sun, located 560 light-years away in the constellation Scorpius. Two confirmed transiting exoplanets are known to orbit this star. An attempt to detect stellar companions using adaptive optics imaging at the Keck telescope was negative however later observations using lucky imaging at the Danish 1.54 m telescope at La Silla Observatory detected a possible companion at 3.8 arcseconds distance from K2-24. This candidate companion being over 8 magnitudes fainter than K2-24 and with a color temperature of 5400 Kelvin, is inconsistent with a bound main sequence companion.
L 98-59 is a bright M dwarf star, located in the constellation of Volans, at a distance of 10.608 parsecs, as measured by Gaia.
K2-25 is a young red dwarf star located in the Hyades cluster. There is a single known Neptune-sized planet in a 3.5 day orbit.