This page summarises the information held within TEPCat for the transiting system K2-257b. Please see here for descriptions of the quantities given below.
| Quantity | Value | Unit |
|---|---|---|
| Reference of discovery paper | 2018AJ....156...78L | |
| Date of discovery paper | 2018 / 7 / 2 | y / m / d |
| Data/telescope used for discovery | K2 | |
| Right ascension | 12 33 06.83 | h m s |
| Declination | −01 57 11.3 | d m s |
| Right ascension (decimal) | 188.27846 | degrees |
| Declination (decimal) | -1.95314 | degrees |
| V-band apparent magnitude | 12.55 | mag |
| K-band apparent magnitude | 9.66 | mag |
| Transit duration | 0.0550 ( 1.320 ) | day hour |
| Transit depth | 0.02 | % |
| Time of mid-transit | 2457583.28750 ± 0.00350 | HJD or BJD |
| Orbital period | 1.6058800 ± 0.0001400 | days |
| Reference for orbital ephemeris | 2018AJ....156...78L |
| Quantity | Value | Unit |
|---|---|---|
| Stellar effective temperature | 3725 +80 −46 | K |
| Stellar metal abundance ([Fe/H] or [M/H]) | −0.03 +0.17 −0.18 | dex |
| Stellar mass | 0.520 ± 0.010 | Msun |
| Stellar radius | 0.500 ± 0.010 | Rsun |
| Stellar logarithmic surface gravity | 4.760 ± 0.010 | c.g.s. |
| Stellar mean density | 2.900 +1.300 −1.500 ( 4.1 +1.8 −2.1 ) | ρsun g cm-3 |
| Orbital eccentricity | ||
| Orbital semimajor axis | 0.02160 ± 0.00020 | AU |
| Planetary mass | Mjup Mearth | |
| Planetary radius | 0.074 +0.005 −0.004 ( 0.829 +0.056 −0.045 ) | Rjup Rearth |
| Planetary surface gravity | m/s2 log(cgs) | |
| Planetary mean density | ρjup g cm-3 | |
| Planetary equilibrium temperature | 789 ± 14 | K |
| Reference of detailed study | 2018AJ....156...78L |
K2-257b does not have an entry in the catalogue of orbital obliquity measurements.
Page generated on 2025/08/27 John Southworth (Keele University, UK)