TOI-1478 b
Gas GiantUninhabitable499 light years awayFound 2021
TOI-1478 b, from the NASA Exoplanet Archive (found 2021). Measured: 280 Earth masses, 0.0818 AU, a 5597 K G-type star. Composition inferred from a mass of 280 Earths, which is giant territory whatever its 0.16x density suggests, with a day locked to its 10.2-day year, as anything orbiting this close would be.
TOI-1478
- Type
- G-type (Yellow (Sun-like))
- Temperature
- 5,597 K
- Radius
- 1.05 ☉
- Mass
- 0.947 ☉
- Known planets
- 1 (this one)
- Luminosity
- 0.971 ☉
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 280.0x 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: 280.0x 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
280.00x Earth (1.67e+27 kg)Radius
6.54x Earth (41,680 km)Surface Gravity
6.54x Earth (64.2 m/s²)Surface Temperature
967 K (694 °C / 1,281 °F)Rotation Period
244.8 hours/day (slower than Earth)Orbital Environment
Star Type
G-type (Yellow (Sun-like))Distance from Star
0.08 AU (12.2 million km)Orbital Period
9 daysTime Dilation
Clocks run 5.7 seconds per year slower than deep space — about 8 minutes over a lifetimeAtmosphere
Hydrogen and helium dominated with trace methane and ammonia
Elemental Composition
H - Hydrogen
53.8%
He - Helium
32.3%
O - Oxygen
5.4%



