TEPCat: K2-18b


 

This page summarises the information held within TEPCat for the transiting planetary system K2-18b. Please see here for descriptions of the quantities given below.

 

Discovery and basic observable quantities:
 
Quantity Value Unit
Reference of discovery paper 2015ApJ...809...25M  
Date of discovery paper 2015 / 3 / 27 y / m / d
Right ascension 11 30 14.51 h m s
Declination +07 35 18.2 d m s
V-band apparent magnitude 13.50 mag
K-band apparent magnitude 8.899 mag
Transit duration 0.1110
( 2.664 )
day
hour
Transit depth 0.27 %
Time of mid-transit   2457264.39144 ± 0.00063     HJD or BJD
Orbital period 32.939614 ± 0.000093 days
Reference for orbital ephemeris   2017ApJ...834..187B  

 

Physical properties from the most recent detailed study:
 
Quantity Value Unit
Stellar effective temperature 3457 ± 39 K
Stellar metal abundance ([Fe/H] or [M/H])   +0.123 ± 0.157 dex
Stellar mass 0.359 ± 0.047   Msun
Stellar radius 0.411 ± 0.038 Rsun
Stellar logarithmic surface gravity c.g.s.
Stellar mean density 5.58 ± 0.89
( 7.9 ± 1.3 )
ρsun
g cm-3
Orbital eccentricity 0.20 ± 0.08  
Orbital semimajor axis   0.1429 +0.0060 −0.0065  AU
Planetary mass 0.0280 +0.0053 −0.0050
( 8.9 +1.7 −1.6 )
Mjup
Mearth
Planetary radius 0.211 ± 0.020
( 2.37 ± 0.22 )
Rjup
Rearth
Planetary surface gravity 14.0 ± 4.3
3.1 ± 0.1
m/s2
log(cgs)
Planetary mean density 3.1 +1.3 −0.9
( 4.1 +1.7 −1.2 )
ρjup
g cm-3
Planetary equilibrium temperature 284 ± 15 K
Reference of detailed study 2018AJ....155..257S  

 

K2-18b does not have an entry in the catalogue of orbital obliquity measurements.

 

K2-18b has not been analysed as part of the Homogeneous Studies of Transiting Extrasolar Planets project.

 


Page generated on 2018/08/14           John Southworth   (Keele University, UK)