K2-245 b
Gas GiantUninhabitable1487 light years awayFound 2018
K2-245 b, from the NASA Exoplanet Archive (found 2018). Measured: 17.4 Earth masses, 0.0959 AU, a 5793 K G-type star. Composition inferred from a measured bulk density of 0.21x Earth's, which only hydrogen and helium can explain, with a day locked to its 11.9-day year, as anything orbiting this close would be.
K2-245
- Type
- G-type (Yellow (Sun-like))
- Temperature
- 5,793 K
- Radius
- 1.25 ☉
- Mass
- 0.83 ☉
- Known planets
- 1 (this one)
- Luminosity
- 1.49 ☉
Published by the NASA Exoplanet Archive. This world’s temperature and habitability score are computed from this star’s measured luminosity, not from a stand-in for its class.
Gas Giant
Magnetic FieldExtreme Activity
Why is this a Gas Giant?Your planet has 86.0% hydrogen and helium, combined with a mass of 17.4x Earth, which exceeds the gas giant threshold.
Gas giants form when massive cores capture enormous atmospheres of light gases. They typically form beyond the 'frost line' where volatiles can condense.
Classification Criteria:
✓ Hydrogen + Helium: 86.0% (>60% required)✓ Mass: 17.4x Earth (>10x required)
Habitability ScoreUninhabitable
Contributing Factors
temperature5
Scorching - hot enough to melt lead, though rock stays solid; no chance for life
atmosphere18
Hydrogen-rich atmosphere typical of gas giants (partially stripped by slow rotation)
water15
No solid surface — any water is locked in a supercritical mantle and hot ice, not oceans
magnetic Field100
Magnetic field provides radiation protection
geology40
Extreme volcanic activity may be hazardous
Organic Chemistry80
Core organic elements (CHNO) present
rotation30
Very slow rotation - extreme temperature swings between eternal day and night sides
Physical Properties
Mass
17.40x Earth (1.04e+26 kg)Radius
2.59x Earth (16,509 km)Surface Gravity
2.59x Earth (25.4 m/s²)Surface Temperature
994 K (721 °C / 1,330 °F)Rotation Period
285.6 hours/day (slower than Earth)Orbital Environment
Star Type
G-type (Yellow (Sun-like))Distance from Star
0.10 AU (14.3 million km)Orbital Period
11 daysAtmosphere
Hydrogen and helium dominated with trace methane and ammonia
Elemental Composition
H - Hydrogen
53.8%
He - Helium
32.3%
O - Oxygen
5.4%



