ExoAtmospheres
IAC community database for exoplanet atmospheric observations
LHS 1140 b
| Planet status | Confirmed |
|---|---|
| Planet type | Cold Super-Earth |
| Period | 24.736 d |
| Mass | 0.022 MJ 6.9916 M⊕ |
| Radius | 0.1541 RJ 1.72592 R⊕ |
| Semi major axis | 0.0936 AU |
| Star name | LHS 1140 |
| Star distance | 12.47 pc |
| Star teff | 3131 K |
| Star radius | 0.186 R☉ |
| Temperature (calculated) | 230 K |
| V | 14.15 mag |
| J | 9.612001 mag |
| K | 8.821 mag |
| Alternate names | TOI-256 b |
| Exoplanet Encyclopaedia |  |
Molecules
He: No detection
|
JWST-NIRISS | No Persistent Helium Absorption in LHS 1140 b: Four JWST/NIRISS SOSS Transits and Multi-epoch Stellar He I Variability2026, Amélie Gressier, Charles Cadieux et al. |
Reanalysis of JWST/NIRISS SOSS He signal and study of stellar He line variability with archival NIRPS data |
He: No detection
|
JWST-NIRISS | Strict Limits on Helium Absorption from LHS 1140 b from Four JWST NIRISS Transits2026, M |
|
He: No detection
|
JWST-NIRISS | No Helium Detected in LHS 1140 b from Four JWST NIRISS/SOSS Transits2026, Katherine A. Bennett, Carlos Gascón et al. |
|
He: Detection
|
G-B: High resolution IR | Helium escaping from the atmosphere of a nearby rocky exoplanet orbiting in a habitable zone2026, Collin Cherubim, Shreyas Vissapragada et al. |
Helium variability may explain the 1.2% absorption in first visit and 0.6% upper limit in a second visit |
Featureless spectra: Detection Dayside Temperature (occultation): 595 K |
JWST-MIRI | Reanalysis of the eclipses of LHS 1140 c: No evidence of an atmosphere and implications for the internal structure of the planet2025, Alexandra Rochon, Étienne Artigau et al. |
|
Featureless spectra: Detection
|
JWST-NIRISS | Transmission Spectroscopy of the Habitable Zone Exoplanet LHS 1140 b with JWST/NIRISS2024, Charles Cadieux, René Doyon et al. |
Stellar contamination dominates the transmission spectrum |
H2O: Upper limit
|
HST WFC3 | A reanalysis of the LHS 1140 b atmosphere observed with the Hubble Space Telescope2024, Alfredo Biagini, Gianluca Cracchiolo et al. |
Confirm the planetary origin of spectral features but without certain molecular determination (H2O or other) |
Featureless spectra: Detection
|
JWST-NIRSpec | LHS 1140 b is a potentially habitable water world2024, Mario Damiano, Aaron Bello-Arufe et al. |
The transmission spectrum is inconsistent with H2-rich atmospheres. No apparent absorption features. |
H2O: Detection
|
HST WFC3 | Hubble WFC3 Spectroscopy of the Habitable-zone Super-Earth LHS 1140 b2021, Edwards, Billy, Changeat, Quentin et al. |