HD 63433 b
Gas GiantUninhabitable73 light years awayFound 2020
HD 63433 b, from the NASA Exoplanet Archive (found 2020). Measured: 21.8 Earth masses, 0.072 AU, a 5553 K G-type star. Composition inferred from a measured bulk density of 2.22x Earth's, far too high for silicates alone — an iron-rich world, with a day locked to its 7.1-day year, as anything orbiting this close would be.
HD 63433
- Type
- G-type (Yellow (Sun-like))
- Spectral type
- G5 V
- Temperature
- 5,553 K
- Radius
- 0.934 ☉
- Mass
- 0.956 ☉
- Known planets
- 3, including this one
- Luminosity
- 0.748 ☉
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 0.0% hydrogen and helium, combined with a mass of 21.8x 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: 0.0% (>60% required)✓ Mass: 21.8x Earth (>10x required)
Habitability ScoreUninhabitable
Contributing Factors
temperature5
Scorching - hot enough to melt lead, though rock stays solid; no chance for life
atmosphere30
Hydrogen-rich atmosphere typical of gas giants
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 Chemistry20
Limited organic chemistry potential
rotation30
Very slow rotation - extreme temperature swings between eternal day and night sides
Physical Properties
Mass
21.80x Earth (1.30e+26 kg)Radius
2.79x Earth (17,798 km)Surface Gravity
2.79x Earth (27.4 m/s²)Surface Temperature
964 K (690 °C / 1,275 °F)Rotation Period
170.6 hours/day (slower than Earth)Orbital Environment
Star Type
G-type (Yellow (Sun-like))Distance from Star
0.07 AU (10.8 million km)Orbital Period
7 daysTime Dilation
Clocks run 6.5 seconds per year slower than deep space — about 9 minutes over a lifetimeAtmosphere
Hydrogen and helium dominated with trace methane and ammonia
Elemental Composition
Si - Silicon
36.6%
Fe - Iron
24.4%
Mg - Magnesium
12.2%



