Astronomical evidence
WASP-76 b completes an orbit in about 1.81 days. Its intense irradiation produces an atmosphere hot enough for gaseous metals to become spectroscopic tracers. High-resolution observations detected an asymmetric absorption signal attributed to neutral iron across the transit. Ehrenreich and colleagues interpreted that asymmetry in terms of atmospheric circulation and iron condensation as gas moves into cooler regions. The frequently used description of iron rain is a physical interpretation of the signal, rather than an observation of falling droplets. Later three-dimensional modeling showed that a strong temperature difference between the limbs could also reproduce the signal without requiring iron condensation. Rotation, winds, chemistry and temperature affect the measured absorption together. Their effects must be separated before a unique weather map can be claimed.
The illustrated viewpoint
Broad folded diamond membrane in a still, inward-folded meditative pose. A fictional shielded observatory above an ultra-hot Jupiter. The illustration shows a fictional shielded viewpoint over the day–night boundary. The copper glow represents an artistic atmosphere, not molten ground. Neither the cloud pattern nor the safety of the imagined habitat follows from the observations.
The illustration shows a fictional shielded viewpoint over the day–night boundary. The copper glow represents an artistic atmosphere, not molten ground. Neither the cloud pattern nor the safety of the imagined habitat follows from the observations. All depicted life is fictional. The visual connection to the cosmos is an artistic theme, not a claimed biological mechanism.
Catalog measurements & sources
Host: WASP-76. Snapshot: 25 September 2026. Errors, limits and source provenance are retained. Calculated values and model estimates are not direct measurements. Unknown is not zero; equilibrium temperature is not surface temperature.
| Quantity / unit | Value / reported errors | Source |
|---|---|---|
| Radius · Earth radii | 20.7815 (+0.863092 / -0.851883) | Ehrenreich et al. 2020 |
| Mass · Earth masses | 284.139 (+4.4496 / -4.13177) | Ehrenreich et al. 2020 |
| Density · g/cm³ | 0.17 (+0.02 / -0.02) | Ehrenreich et al. 2020 |
| Orbital period · days | 1.80988 (+6.4e-07 / -5.6e-07) | Ehrenreich et al. 2020 |
| Orbital semimajor axis · AU | 0.033 (+0.0002 / -0.0002) | Ehrenreich et al. 2020 |
| Eccentricity | 0 | Ehrenreich et al. 2020 |
| Inclination · degrees | 89.623 (+0.005 / -0.034) | Ehrenreich et al. 2020 |
| Irradiation · Earth flux | 4104 (+896 / -896) | Ehrenreich et al. 2020 |
| Equilibrium temperature · K | 2228 (+122 / -122) | Ehrenreich et al. 2020 |
| Stellar effective temperature · K | 6329 (+65 / -65) | Ehrenreich et al. 2020 |
| Stellar radius · Solar | 1.756 (+0.071 / -0.071) | Ehrenreich et al. 2020 |
| Stellar mass · Solar | 1.458 (+0.021 / -0.021) | Ehrenreich et al. 2020 |
| Stellar luminosity · log Solar | 0.65418 (+0.0369 / -0.03718) | Fu et al. 2021 |
| Stellar age · Gyr | 1.816 (+0.274 / -0.274) | Ehrenreich et al. 2020 |
| Stellar metallicity · dex | 0.366 (+0.053 / -0.053) | Ehrenreich et al. 2020 |
| Distance · pc | 194.459 (+6.206 / -5.839) | TICv8 |
References
- NASA Exoplanet Archive · WASP-76 b · composite snapshot, 25 September 2026
- Ehrenreich et al. 2020 · Nightside condensation of iron in an ultra-hot giant
- Wardenier et al. 2021 · Decomposing the iron signal with three-dimensional radiative transfer
- West et al. 2016
- Ehrenreich et al. 2020
- Fu et al. 2021
- TICv8