Planet K2-18 b

Name K2-18 b
Planet Status Confirmed
Discovered in 2015
Mass 0.02715 (± 0.00425) MJ +
Mass*sin(i)
Semi-Major Axis 0.1591 (± 0.0004) AU +
Orbital Period 32.944 (± 0.002) day +
Eccentricity 0.2 (± 0.08)
ω
Tperi
Radius 0.24186 (± 0.0058) RJ +
Inclination 89.5785 ( -0.0088 +0.0079 ) deg
Update 2020-05-09
Detection Method Primary Transit
Mass Detection Method Theoretical
Radius Detection Method Primary Transit
Primary transit 2457264.39144 (± 0.00065) JD
Secondary transit
λ
Impact Parameter b
Time Vr=0
Velocity Semiamplitude K 3.55 ( -0.58 +0.57 ) m/s
Calculated temperature
Measured temperature
Hottest point longitude
Geometric albedo
Surface gravity log(g/gH)
Alternate Names EPIC 201912552 b

Star

K2-18
Name K2-18
Distance 34.0 (± 4.0) pc
Spectral type
Apparent magnitude V 13.5
Mass 0.413 (± 0.043) MSun
Age
Effective temperature 3503.0 (± 60.0) K
Radius 0.394 (± 0.038) RSun
Metallicity [Fe/H] 0.09 (± 0.09)
Detected Disc
Magnetic Field
RA2000 11:30:14.5
Dec2000 +07:35:18
Alternate Names EPIC 201912552
Planetary system
2 planets

More data

Atmospheric parameters

Temperatures

Data Source Type Result Value Result Figure Notes Reference

Molecules

Molecule Data Source Type Result Value Result Figure Notes Reference
CH4 Measurements Detected 2020 - MADHUSUDHAN N.
H2O Measurements Detected 2020 - MADHUSUDHAN N.
Measurements Detected 2019 - BENNEKE B.
Measurements Detected 2019 - TSIARAS A.
NH3 Measurements Detected 2020 - MADHUSUDHAN N.

Observability Predictor


Related publications

Tidal evolution of exoplanetary systems hosting potentially habitable exoplanets. The cases of LHS-1140 b-c and K2-18 b-c
2020 GOMES G. & FERRAZ-MELLO S.
MNRAS, 494, 5082
paper   arxiv

The high-energy environment and atmospheric escape of the mini-Neptune K2-18 b
2020 dos SANTOS L., EHRENREICH D., BOURRIER V., ASTUDILLO-DEFRU N., BONFILS X. et al.
Astron. & Astrophys., 634, L4
paper  arxiv  

Consistently Simulating a Wide Range of Atmospheric Scenarios for K2-18b with a Flexible Radiative Transfer Module
2020 SCHEUCHER M., WUNDERLICH F., GRENFELL J., GODOLT M., SCHREIER F. et al.
ApJ., accepted
arxiv

Formation of secondary atmospheres on terrestrial planets by late disk accretion
2020 KRAL Q., DAVOULT J. & CHARNEY B.
Nature Astronomy
paper   arxiv  

Disentangling Atmospheric Compositions of K2-18 b with Next Generation Facilities
2020 CHANGEAT Q., EDWARDS B., AL-REFAIE A., TSIARAS A., WALDMANN I. & TINETTI G.
ApJ, submitted
arxiv  

The interior and atmosphere of the habitable-zone exoplanet K2-18b
2020 MADHUSUDHAN N., NIXON M., WELBANKS L., PIETTE A. & BOOTH R.
ApJ. Letters, accepted
arxiv  

Water vapour in the atmosphere of the habitable- zone eight-Earth-mass planet K2-18 b
2019 TSIARAS A., WALDMANN I., TINETTI G., TENNYSON J. & YOURCHENKO S.
Nature Astronomy, in press
paper  arxiv  

Mass-Radius relationship for M dwarf exoplanets: Comparing nonparametric and parametric methods
2019 KANODIA Sh., WOLFGANG A., STEFANSSON G., NING B. & MAHADEVAN S.
ApJ, submitted
arxiv  

Water Vapor on the Habitable-Zone Exoplanet K2-18b
2019 BENNEKE B., WONG I., PIAULET C., KNUTSON H., CROSSFIELD I. et al.
ApJ. Letters, 887, L14
paper  arxiv  

The weight of a world
2019 Anonymous
Nature Astronomy, 3, 875
paper  

The K2-18b Planetary System: Estimates of the Age and X-UV Irradiances of a Habitable Zone "Wet" Sub-Neptune Planet
2019 GUINAN E. & ENGIE S.
Res. Notes AAS, 3, 189
paper  

The CARMENES Search for Exoplanets around M Dwarfs: A Low-mass Planet in the Temperate Zone of the Nearby K2-18
2018 SARKIS P., HENNING Th., KÜRSTER M., TRIFONOV T., ZECHMEISTER M. et al.
Astron. J., 155, 257
arxiv  

The CARMENES search for exoplanets around M dwarfs: A low-mass planet in the temperate zone of the nearby K2-18
2018 PAULA S., HENNING Th., MARTIN K., TRIFON T., ZECHMEISTER L., et al.
Astron. J., accepted
arxiv  

Characterization of the K2-18 multi-planetary system with HARPS: A habitable zone super-Earth and discovery of a second, warm super-Earth on a non-coplanar orbit
2017 CLOUTIER R., ASTUDILLO-DEFRU N., DOYON R., BONFILS X., ALMENARA J. et al.
Astron. & Astrophys., 608, A35
paper  arxiv   ADS  

Spitzer Observations Confirm and Rescue the Habitable-Zone Super-Earth K2-18b for Future Characterization
2016 BENNEKE B., WERNER M., PETIGURA E., KNUTSON H., DRESSING C. et al.
ApJ, 834, 187
paper  arxiv  ADS  

Stellar and Planetary Properties of K2 Campaign 1 Candidates and Validation of 17 Systems, Including a Planet Receiving Earth-like Insolation
2015 MONTET B., MORTON T., FOREMAN-MACKEY D., JOHNSON J., HOGG D. et 4 additional authors
ApJ, 809, 25
arxiv   paper   ADS