This page summarises the information held within TEPCat for the transiting planetary system K2-138b. Please see here for descriptions of the quantities given below.
| Quantity | Value | Unit |
|---|---|---|
| Reference of discovery paper | 2018AJ....155...57C | |
| Date of discovery paper | 2018 / 1 / 12 | y / m / d |
| Data/telescope used for discovery | K2 | |
| Right ascension | 23 15 47.77 | h m s |
| Declination | −10 50 58.9 | d m s |
| Right ascension (decimal) | 348.94904 | degrees |
| Declination (decimal) | -10.84969 | degrees |
| V-band apparent magnitude | 12.21 | mag |
| K-band apparent magnitude | 10.31 | mag |
| Transit duration | 0.0721 ( 1.730 ) | day hour |
| Transit depth | 0.03 | % |
| Time of mid-transit | 2457773.31683 ± 0.00091 | HJD or BJD |
| Orbital period | 2.35309 ± 0.00022 | days |
| Reference for orbital ephemeris | 2019A+A...631A..90L |
| Quantity | Value | Unit |
|---|---|---|
| Stellar effective temperature | 5350 ± 80 | K |
| Stellar metal abundance ([Fe/H] or [M/H]) | +0.14 ± 0.10 | dex |
| Stellar mass | 0.93 ± 0.02 | Msun |
| Stellar radius | 0.86 +0.03 −0.02 | Rsun |
| Stellar logarithmic surface gravity | 4.54 +0.02 −0.04 | c.g.s. |
| Stellar mean density | 1.46 +0.10 −0.19 ( 2.06 +0.14 −0.27 ) | ρsun g cm-3 |
| Orbital eccentricity | 0.0 +0.189 −0.0 | |
| Orbital semimajor axis | 0.03385 +0.00023 −0.00029 | AU |
| Planetary mass | 0.0098 ± 0.0035 ( 3.1 ± 1.1 ) | Mjup Mearth |
| Planetary radius | 0.135 +0.010 −0.007 ( 1.513 +0.112 −0.078 ) | Rjup Rearth |
| Planetary surface gravity | m/s2 log(cgs) | |
| Planetary mean density | 3.7 +1.5 −1.3 ( 4.9 +2.0 −1.7 ) | ρjup g cm-3 |
| Planetary equilibrium temperature | 1308 +24 −20 | K |
| Reference of detailed study | 2019A+A...631A..90L |
K2-138b does not have an entry in the catalogue of orbital obliquity measurements.
Page generated on 2026/01/29 John Southworth (Keele University, UK)