Astronomical evidence
HR 8799 e is a directly imaged young giant. Interferometry with the GRAVITY instrument has also provided positional information and a K-band spectrum, which atmospheric models use to investigate molecular absorption and cloud opacity. [2] Infrared brightness can be powered by a young planet's remaining internal heat. It does not imply a visible lava surface. Mass, radius and atmospheric properties depend on model interpretation; the accompanying catalog retains their source-specific uncertainties. [1] The image places an observer on an explicitly invented icy moon and gives the giant a restrained ember coloration to interpret its thermal emission.
The illustrated viewpoint
Broad pearl-grey humanoid with cranial fins and layered dark armor in meditation. A ground-level ice cave on an invented moon of HR 8799 e. The icy moon, atmosphere, open cave, warrior and mineral artwork are fictional. HR 8799 e is a young gas giant, not the solid ice beneath the observer. The planet's ember and violet palette translates its thermal character into visible art, rather than predicting its true naked-eye color. Clouds, illumination, angular scale and satellite stability are not modeled.
The icy moon, atmosphere, open cave, warrior and mineral artwork are fictional. HR 8799 e is a young gas giant, not the solid ice beneath the observer. The planet's ember and violet palette translates its thermal character into visible art, rather than predicting its true naked-eye color. Clouds, illumination, angular scale and satellite stability are not modeled. All beings and cultures are fictional. Apparent sizes, phases and exposure are artistic, not a calibrated sky simulation. Cosmic connection is a visual theme, not an observed biological mechanism.
Catalog measurements & sources
Host: HR 8799. 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 | 13.1145 (+1.45717 / -1.23299) | Gravity Collaboration et al. 2019 |
| Mass · Earth masses | 3178.3 (+2224.81 / -1271.32) | Gravity Collaboration et al. 2019 |
| Density · g/cm³ | 7.74 | Calculated Value |
| Orbital period · days | 20815.6 (+1128.62 / -1128.62) | Zurlo et al. 2016 |
| Orbital semimajor axis · AU | 16.4 (+2.1 / -1.1) | Gravity Collaboration et al. 2019 |
| Eccentricity | 0.15 (+0.08 / -0.08) | Gravity Collaboration et al. 2019 |
| Inclination · degrees | 25 (+8 / -8) | Gravity Collaboration et al. 2019 |
| Irradiation · Earth flux | 0.0201 (+0.004 / -0.004) | Calculated Value |
| Equilibrium temperature · K | 1150 (+50 / -50) | Gravity Collaboration et al. 2019 |
| Stellar effective temperature · K | 7400 | Gravity Collaboration et al. 2019 |
| Stellar radius · Solar | 1.49338 (+0.049341 / -0.050935) | Konopacky et al. 2016 |
| Stellar mass · Solar | 1.51 (+0.038 / -0.024) | Zurlo et al. 2016 |
| Stellar luminosity · log Solar | 0.73347 (+0.01645 / -0.01535) | Konopacky et al. 2016 |
| Stellar age · Gyr | 0.03 | Gravity Collaboration et al. 2019 |
| Stellar metallicity · dex | -0.5 | Gravity Collaboration et al. 2019 |
| Distance · pc | 41.2441 (+0.1515 / -0.1505) | TICv8 |