HD 115404 A b
Gas GiantUninhabitable36 light years awayFound 2022
HD 115404 A b, from the NASA Exoplanet Archive (found 2022). Measured: 30.8 Earth masses, 0.088 AU, a 5019 K K-type star. Composition inferred from a measured bulk density of 0.14x Earth's, which only hydrogen and helium can explain, with a day locked to its 10.5-day year, as anything orbiting this close would be.
HD 115404 A
- Type
- K-type (Orange)
- Spectral type
- K2V
- Temperature
- 5,019 K
- Radius
- 0.727 ☉
- Mass
- 0.83 ☉
- Known planets
- 2, including this one
- Luminosity
- 0.302 ☉
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 30.8x 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: 30.8x 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
30.80x Earth (1.84e+26 kg)Radius
3.13x Earth (19,971 km)Surface Gravity
3.13x Earth (30.8 m/s²)Surface Temperature
696 K (423 °C / 794 °F)Rotation Period
252.0 hours/day (slower than Earth)Orbital Environment
Star Type
K-type (Orange)Distance from Star
0.09 AU (13.2 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%



