Astronomical evidence
Kepler-1661 b travels around both members of an eclipsing binary. Its 175.06 ± 0.06-day orbit surrounds the moving pair, rather than belonging to either star individually. The discovery analysis measured a planetary radius of 3.87 ± 0.06 Earth radii. Transits in such a system depend on the motion of the planet and the stars together. A star is a moving target, so the intervals and durations need not follow the simple pattern of a planet crossing one stationary stellar disk. Modeling the stellar eclipses alongside the planetary transits constrains the shared geometry. The catalog mass, 17 ± 12 Earth masses, carries a large uncertainty. A precise-looking orbital period does not imply comparable precision for every other parameter. The two stars also make the illumination vary with orbital configuration.
The illustrated viewpoint
Muscular toroidal organism in a still, inward-folded meditative pose. An unconfirmed fictional moon of the real circumbinary planet. This scene places the viewpoint on an invented moon. No such moon is established by these sources. The nearby planetary disk, paired suns, shadows and rocky terrain form an illustrative arrangement, not a reconstructed view at a calculated observing date.
This scene places the viewpoint on an invented moon. No such moon is established by these sources. The nearby planetary disk, paired suns, shadows and rocky terrain form an illustrative arrangement, not a reconstructed view at a calculated observing date. All depicted life is fictional. The visual connection to the cosmos is an artistic theme, not a claimed biological mechanism.
Catalog measurements & sources
Host: Kepler-1661. 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 | 3.87 (+0.06 / -0.06) | Socia et al. 2020 |
| Mass · Earth masses | 17 (+12 / -12) | Socia et al. 2020 |
| Density · g/cm³ | 1.6 (+1.1 / -1.1) | Socia et al. 2020 |
| Orbital period · days | 175.06 (+0.06 / -0.06) | Socia et al. 2020 |
| Orbital semimajor axis · AU | 0.633 (+0.005 / -0.005) | Socia et al. 2020 |
| Eccentricity | 0.057 (+0.005 / -0.005) | Socia et al. 2020 |
| Inclination · degrees | 89.46 (+0.02 / -0.02) | Socia et al. 2020 |
| Irradiation · Earth flux | 0.88 | Socia et al. 2020 |
| Equilibrium temperature · K | 243 | Socia et al. 2020 |
| Stellar effective temperature · K | 5100 (+100 / -100) | Socia et al. 2020 |
| Stellar radius · Solar | 0.762 (+0.01 / -0.01) | Socia et al. 2020 |
| Stellar mass · Solar | 0.841 (+0.022 / -0.022) | Socia et al. 2020 |
| Stellar luminosity · log Solar | -0.51299 (+0.0087 / -0.00887) | Gaia DR2 |
| Stellar age · Gyr | 2 (+1 / -1) | Socia et al. 2020 |
| Stellar metallicity · dex | -0.12 (+0.1 / -0.1) | Socia et al. 2020 |
| Distance · pc | 410.607 (+2.8825 / -2.8825) | TICv8 |