| The Star | |||||
|---|---|---|---|---|---|
| Simbad GAIA 2MASS |
K2-238 DR2 2631270757088861312 J23104905-0751270 |
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| RA | 23:10:49.0455 | DEC | -07:51:27.077 | ||
| Parallax 0.148 mas |
P.M. RA -9.24 mas/y |
P.M. DEC -8.726 mas/y |
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| MagV 13.75 |
MagR 13.89 |
MagI* 12.938 |
MagJ 12.464 |
MagH 12.095 |
MagK 12.032 |
| MagG 13.664 |
MagGBP 14.029 |
MagGRP 13.089 |
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| *Calculated from GAIA magnitudes. | |||||
Ephemeris
- Verified 
|
|||||
|---|---|---|---|---|---|
| Kokori et al. 2025 | |||||
| Mid-time 2457984.06023 ± 0.00031 BJDTDB |
|||||
| Period 3.2046898 ± 2.3e-06 days |
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| Transit Parameters | |||||
| Soto et al. 2018 | |||||
| Rp/Rs 0.08 ± 0.003 |
a/Rs 6.3 +0.7 -0.5 |
i 84.5 +1.8 -1.5 deg |
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| e - |
ω - deg |
||||
| DepthR* 7.66 mmag |
Duration* 3.51 hours |
||||
|
*Calculated from the other parameters, using PyLightcurve.
**Adjusted based on the space observations. |
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| Limb Darkening Parameters | |||||
| Soto et al. 2018 | |||||
| Teff 5630.0 +78.0 -78.0 K |
Log(g) 4.11 +0.07 -0.07 cm/s2 |
Fe/H 0.34 +0.04 -0.04 dex |
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| ExoClock Status | |||||
|---|---|---|---|---|---|
| Observing Priority | MEDIUM | ||||
| Minimum aperture | 17.71" | ||||
| Total Observations (Recent) | 23 (1) | ||||
| O-C | -3.55 ± 1.65 minutes | ||||
| ExoClock Observations (Recent) | 8 (1) | ||||
| Space Observations (Recent) | 15 (0) | ||||
| ETD Observations (Recent) | 0 (0) | ||||
| Literature Mid-times (Recent) | 0 (0) | ||||
| Kepler Rp/Rs | 0.08343 ± 0.00038 | ||||
| TESS Rp/Rs | 0.0824 ± 0.0031 | ||||
ExoClock Observations |
||||
| Planet Observation Date |
Observer Observatory |
Telescope Camera / Filter / Exp [s] |
O-C minutes |
|
|---|---|---|---|---|
| K2-238b (MEDIUM) 2025-09-29 | Lorenzo Betti Osservatorio Polifunzionale del Chianti | RC-80cm Moravian G4 - KAF 09000 / R / 100.0 | -4.74 ± 2.59 | |
| K2-238b (MEDIUM) 2024-08-25 | Yves Jongen Deep Sky Chile | Plane Wave CDK 17" Moravian 4G / Lum / 180.0 | 0.91 ± 4.46 | |
| K2-238b (MEDIUM) 2024-08-25 | Anaël Wünsche El Sauce Observatory | CDK Planewave Chili Moravian G4 16k / Lum / 120.0 | -5.43 ± 7.49 | |
| K2-238b (MEDIUM) 2024-08-09 | Yves Jongen Deep Sky Chile | Plane Wave CDK 17" Moravian 4G / Lum / 180.0 | -3.63 ± 2.59 | |
| K2-238b (MEDIUM) 2022-10-15 | Adam Popowicz Otivar dome2 | Newton 12" ASA ASI ZWO 1600MM / R / 240.0 | -10.85 ± 7.63 | |
| K2-238b (MEDIUM) 2022-09-04 | Jean-Pascal Vignes Deep Sky Chile | Planewave CDK400 QHYCCD 600M / Lum / 120.0 | -12.77 ± 4.32 | |
| K2-238b (MEDIUM) 2022-08-19 | Yves Jongen Deep Sky Chile | Plane Wave CDK 17" Moravian 4G / Lum / 180.0 | 3.72 ± 5.76 | |
| K2-238b (MEDIUM) 2020-09-19 | Taewoo Kim Deokheung Optical Astronomy Observatory | NYSC 1m Telescope FLI PL-16803 or PI SOPHIA-2048B / R / 180.0 | -4.38 ± 5.76 | |
Space Observations |
||||
| Planet Observation Date |
Mission | O-C minutes |
||
| K2-238b (MEDIUM) 2023-10-13 | TESS | -7.03 ± 8.93 | ||
| K2-238b (MEDIUM) 2023-10-06 | TESS | 2.3 ± 8.5 | ||
| K2-238b (MEDIUM) 2023-09-23 | TESS | 1.38 ± 5.18 | ||
| K2-238b (MEDIUM) 2021-09-10 | TESS | 0.28 ± 6.34 | ||
| K2-238b (MEDIUM) 2021-09-07 | TESS | 2.13 ± 6.34 | ||
| K2-238b (MEDIUM) 2021-09-03 | TESS | -6.81 ± 7.92 | ||
| K2-238b (MEDIUM) 2021-08-22 | TESS | 11.85 ± 7.63 | ||
| K2-238b (MEDIUM) 2018-09-13 | K2 | 1.16 ± 0.66 | ||
| K2-238b (MEDIUM) 2017-02-20 | K2 | -4.32 ± 3.17 | ||
| K2-238b (MEDIUM) 2017-02-16 | K2 | -2.12 ± 1.12 | ||
| K2-238b (MEDIUM) 2017-01-12 | K2 | 0.47 ± 1.4 | ||
| K2-238b (MEDIUM) 2017-01-09 | K2 | -5.52 ± 2.16 | ||
| K2-238b (MEDIUM) 2016-12-27 | K2 | 0.93 ± 0.95 | ||
| K2-238b (MEDIUM) 2016-12-24 | K2 | 0.15 ± 0.65 | ||
| K2-238b (MEDIUM) 2016-12-18 | K2 | -0.45 ± 1.04 | ||