ExoAtmospheres
IAC community database for exoplanet atmospheric observations
GJ 436 b
| Planet status | Confirmed |
|---|---|
| Planet type | Warm Neptune |
| Period | 2.64394 d |
| Mass | 0.0584 MJ 18.55952 M⊕ |
| Radius | 0.3252 RJ 3.64224 R⊕ |
| Semi major axis | 0.02887 AU |
| Star name | GJ 436 |
| Star distance | 10.2 pc |
| Star teff | 3684 K |
| Star radius | 0.464 R☉ |
| Temperature (calculated) | 580 K |
| V | 10.68 mag |
| J | 6.9 mag |
| K | 6.073 mag |
| Alternate names | |
| Exoplanet Encyclopaedia |  |
Molecules
Featureless spectra: Detection H: Upper limit
|
G-B: High resolution visible | The atmosphere of the warm Neptune GJ 436 b probed with ESPRESSO2026, E. Herrero-Cisneros, M. R. Zapatero Osorio et al. |
No evidence of atmospheric features (single line or CCF) using two transits. |
Featureless spectra: Detection
|
G-B: High resolution IR | Searching for Molecular Signatures in 14 Transiting Exoplanets with SPIRou2026, A. Masson, S. Vinatier et al. |
SPIRou cross-correlation observations does not show molecular signals |
CO2: Upper limit CH4: Upper limit
|
G-B: High resolution IR | Possible stratospheric emission in the warm Neptune GJ 436 b from high-resolution spectroscopy2026, Luke Finnerty, Michael P Fitzgerald et al. |
|
H2O: Upper limit CH4: Upper limit CO: Upper limit
|
G-B: High resolution IR | Tighter constraints on the atmosphere of GJ 436 b from combined high-resolution CARMENES and CRIRES<SUP>+</SUP> observations2026, Peláez-Torres, A., Sánchez-López, A. et al. |
No molecular signal with CARMENES-CRIRES+ in cc. Injection recovery test for upper limits. ELT/ANDES simulations. |
CO2: Upper limit Albedo: 0.66 Dayside Temperature (occultation): 662 K |
JWST-NIRCam | A JWST Panchromatic Thermal Emission Spectrum of the Warm Neptune Archetype GJ 436b2025, Sagnick Mukherjee, Everett Schlawin et al. |
|
Na: Upper limit
|
G-B: High resolution visible | The GAPS programme at TNG XLVI. A homogeneous search for Na i and its possible variability in ten gas giant exoplanets2024, D. Sicilia, L. Malavolta et al. |
|
H2O: Upper limit CO: Upper limit CH4: Upper limit
|
G-B: High resolution IR | Peering above the clouds of the warm Neptune GJ 436b with CRIRES+2024, Natalie Grasser, Ignas A. G. Snellen et al. |
No transmission signals detected with CRIRES+ |
He: Upper limit
|
G-B: High resolution IR | Probing atmospheric escape through metastable He I triplet lines in 15 exoplanets observed with SPIRou2024, A. Masson, S. Vinatier et al. |
|
He: Upper limit
|
G-B: High resolution IR | LV: A HeI survey of close-in giant planets hosted by M-K dwarf stars with GIANO-B2024, G. Guilluy, M. C. D'Arpa et al. |
Non detection of He with GIANO-B |
FeH: Upper limit
|
G-B: High resolution IR | A Search for FeH in Hot-Jupiter Atmospheres with High-dispersion Spectroscopy2020, Kesseli, Aurora Y., Snellen, I. A. G. et al. |
|
He: Upper limit
|
G-B: High resolution IR | Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b2018, Lisa Nortmann, Enric Pallé et al. |
He analysis in the appendix |
H: No detection
|
G-B: High resolution visible | A search for H$α$ absorption around KELT-3 b and GJ 436 b2016, P. Wilson Cauley, Seth Redfield et al. |
Non detection of Halpha line |
H: Detection
|
HST STIS | A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b2015, Ehrenreich, David, Bourrier, Vincent et al. |
Ly-alpha detection |
H: Detection
|
HST STIS | Lyman-$α$ Transit Spectroscopy and the Neutral Hydrogen Tail of the Hot Neptune GJ436b2014, Jennifer R. Kulow, Kevin France et al. |
Lyman alpha detection |