K2-138

K2-138

Artist’s impression of the K2-138 exoplanetary system
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 23h 15m 47.76861s[1]
Declination −10° 50′ 58.8955″[1]
Apparent magnitude (V) 12.21[2]
Characteristics
Evolutionary stage Main sequence
Spectral type K1V[2]
Astrometry
Radial velocity (Rv)0.77±0.49[1] km/s
Proper motion (μ) RA: −1.080 mas/yr[1]
Dec.: −10.675 mas/yr[1]
Parallax (π)4.9437 ± 0.0150 mas[1]
Distance660 ± 2 ly
(202.3 ± 0.6 pc)
Details
Mass0.93 ± 0.06[2] M
Radius0.86 ± 0.08[2] R
Luminosity~0.554[3] L
Surface gravity (log g)4.59 ± 0.07[2] cgs
Temperature5378 ± 60[2] K
Metallicity [Fe/H]+0.16 ± 0.04[2] dex
Age2.3+0.44
−0.36
[4] Gyr
Other designations
EE-1, EPIC 245950175, 2MASS J23154776-1050590
Database references
SIMBADdata

K2-138, also designated EPIC 245950175 or EE-1,[5] is a large early K-type main sequence star with a system of at least 6 planets discovered by citizen scientists. Four were found in the first two days of the Exoplanet Explorers project on Zooniverse in early April 2017, while two more were revealed in further analysis. The system is about 660 light-years (200 parsecs) away in the constellation Aquarius, within K2 Campaign 12.

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Christiansen was invoked but never defined (see the help page).
  3. ^ "HEC: Exoplanets Calculator - Planetary Habitability Laboratory @ UPR Arecibo". Archived from the original on 2019-09-05. Retrieved 2018-02-10.
  4. ^ Cite error: The named reference Lopez was invoked but never defined (see the help page).
  5. ^ "Zooniverse".