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 |
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
