Planet K2-138 c

Name K2-138 c
Planet Status Confirmed
Discovered in 2017
Mass 0.0198 (± 0.0038) MJ
Mass*sin(i)
Semi-Major Axis 0.04454 ( -0.00032 +0.00032 ) AU
Orbital Period 3.55987 ( -0.00022 +0.00023 ) day
Eccentricity 0.296 ( -0.296 +0.0 )
ω 200.0 ( -27.0 +60.0 ) deg
Tperi
Radius 0.225 ( -0.014 +0.03 ) RJ
Inclination 87.5 ( -3.3 +1.8 ) deg
Update 2021-03-26
Detection Method Primary Transit
Mass Detection Method Spectrum
Radius Detection Method Primary Transit
Primary transit 2457740.32182 (± 0.00089) JD
Secondary transit
λ
Impact Parameter b 0.47 ( -0.32 +0.32 )
Time Vr=0
Velocity Semiamplitude K 2.8 (± 0.55) m/s
Calculated temperature 1140.0 ( -17.0 +21.0 ) K
Measured temperature
Hottest point longitude
Geometric albedo
Surface gravity log(g/gH)
Alternate Names 2MASS J23154776-1050590 c, EPIC 245950175 c, WISE J231547.76-105059.0 c

Star

K2-138
Name K2-138
Distance 183.0 (± 17.0) pc
Spectral type K1 V
Apparent magnitude V 12.21
Mass 0.93 (± 0.06) MSun
Age
Effective temperature 5378.0 (± 60.0) K
Radius 0.86 (± 0.08) RSun
Metallicity [Fe/H] 0.16 (± 0.04)
Detected Disc
Magnetic Field
RA2000 23:15:47.8
Dec2000 -10:50:59
Alternate Names EPIC 245950175, 2MASS J23154776-1050590, WISE J231547.76-105059.0
Planetary system
6 planets

More data

Observability Predictor

Remarks

February 2018 : K2-138 is the first exoplanet discovery by citizen scientists participating in the Exoplanet Explorers project on the Zooniverse platform.

Related publications

Architectures of Compact Super-Earth Systems Shaped by Instabilities
2022 GOLDBERG M. & BATYGIN K.
Astron. J., 163, 201
paper   arxiv  

Detection capability of ground-based meter-sized telescopes for shallow exoplanet transits
2022 MALLONN M., POPPENHAEGER K., GRANZER T., WEBER M. & STRASSMEIER K.
Astron. & Astrophys., 657, A102
paper   arxiv  

Confirming the 3:2 Resonance Chain of K2-138
2022 MACDONALD M., FEIL L., QUINN T. & RICE D.
Astron. J., 163, 162
paper   arxiv  

The orbital evolution of resonant chains of exoplanets incorporating circularisation produced by tidal interaction with the central star with application to the HD 158259 and EPIC 245950175 systems
2021 PAPALOIZOU J.
Cel. Mech. & Dyn. Astron., accepted
arxiv

K2-138 g: Spitzer Spots a Sixth Planet for the Citizen Science System
2021 HARDEGREE-ULLMAN K., CHRISTIANSEN J., CIARDI D., CROSSFIELD I. et al.
Astron. J., 161, 219
paper   arxiv

Transit Duration Variations in Multi-Planet Systems
2020 BOLEY A., VAN LAERHOVEN Ch., PAULA A. & CONTRERAS G.
Astron. J., 159, 207
paper   arxiv

Exoplanet characterisation in the longest known resonant chain: the K2-138 system seen by HARPS
2019 LOPEZ T., BARROS S., SANTERNE A., DELEUIL M., ADIBEKYAN V. et al.
Astron. & Astrophys., 631, A90
paper  arxiv  

The K2-138 System: A Near-Resonant Chain of Five Sub-Neptune Planets Discovered by Citizen Scientists
2018 CHRISTIANSEN J., CROSSFIELD I., BARENTSEN G., LINTOTT Ch., BARCLAY Th. et al.
Astron. J., 155, 57
paper  arxiv