Kepler-90 g
Planet· orbits Kepler-90
Kepler-90 g — a puffy gas giant (8.1 R⊕) on a 211-day orbit. Because its mass (~15 M⊕) is measured from the way the planets tug each other's transit times, its density is real — a remarkably low-density, inflated world. Never imaged.
Open in 3D viewSee Kepler-90 g in the live, interactive 3D map
Key facts
Mass
8.96 × 10²⁵ kg
15 M⊕
Radius
51,605 km
8.1× wider than Earth
Surface gravity
2.25 m/s²
23% of Earth's gravity
Year
211 Earth days
Distance from Kepler-90
0.717 AU
Science
Physical
- Mass
- 8.96 × 10²⁵ kg · 15 M⊕
- Shaw et al. 2025 — transit-timing variations
- Radius
- 51,605 km · 8.1× wider than Earth
- Cabrera et al. 2014 — transit
- Density
- 156 kg/m³ · 0.16× water
- Computed from mass and radius
- Surface gravity
- 2.25 m/s² · 23% of Earth's gravity
- Computed from mass and radius
- Escape velocity
- 15.2 km/s · 1.36× Earth's escape velocity
- Computed from mass and radius
Orbital
- Semi-major axis
- 0.717 AU
- From the NASA Exoplanet Archive (transit + orbit fit)
- Eccentricity
- 0.0292
- From the NASA Exoplanet Archive (transit + orbit fit)
- Inclination
- 0.00 °
- From the NASA Exoplanet Archive (transit + orbit fit)
- Orbital period
- 210.6 days
- From the NASA Exoplanet Archive (transit + orbit fit)
- Perihelion
- 0.696 AU
- Computed from the orbital elements
- Aphelion
- 0.738 AU
- Computed from the orbital elements
- Mean orbital velocity
- 37 km/s
- Computed from the orbital elements
Composition
- Bulk composition
- A gas giant (8.1 R⊕) whose mass (~15 M⊕) is measured from transit-timing variations, so its density is real — a remarkably inflated, low-density world of hydrogen and helium. Mass: Shaw et al. 2025; radius: Cabrera et al. 2014.
- Cloud appearance
- Appearance based on NASA/JPL-Caltech's artist's concept. No spacecraft has imaged this world, so its real appearance is unknown — The banded clouds shown are a representation of its class, shown only in Visual mode; Realism shows a plain spectral colour.
Radiation & temperature
- Insolation
- 3.45 S⊕ · 3.45× the sunlight Earth receives
- Computed from Kepler-90's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
- Equilibrium temperature
- 342 K (69 °C)
- Computed model value — not measured.
Discovery & history
- Method
- Transit detection
- Name
- Designated 'g' under the IAU convention that letters a star's planets 'b', 'c', 'd'... in the order found (the star is the unwritten 'a'); no IAU proper name has been assigned.
One of the seven planets confirmed around Kepler-90 in 2013. Its mass is measured from transit-timing variations among the crowded planets (Shaw et al. 2025); the radius is the Kepler discovery value (Cabrera et al. 2014, adopted by Shaw).
Images
No telescope has imaged this world — it is known only from the tiny dip it makes crossing its star. Only its host system has been pictured (see the system view); its true surface appearance is unknown.