Key parameters at a glance
- A radius of 10.47 Earth radii
- A mass of 6,992.00 Earth masses
- Surface gravity around 63.81 g
- Semi-major axis 8.0000 AU
- Equilibrium temperature 450 K (177 °C)
- Distance from Earth 32.94 light-years
- Earth Similarity Index 0.250
- Travel time at Voyager 1 speed 580,928 years
WISEP J121756.91+162640.2 A b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1733of 1771
top 97.8%
This planet
10.47R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | WISEP J121756.91+162640.2 A b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 10.47 | 11.21 |
| Mass (M⊕) | 1.00 | 6,992.00 | 317.83 |
| Density (g/cm³) | 5.51 | 33.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 63.81 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 6,992.000 M⊕ | Direct mass measurement (not derived). |
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
Orbital period for this planet has not yet been measured.
Eq. Temperature
450K
(177 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.250
0 = alien, 1 = Earth-identical
Insufficient insolation data — the surface is too hot to retain surface water.
Discovery Paper
Primary reference
Liu et al. 2013Instrument
NIRC2 Camera
Publication
2012-10
Observation locale
Ground
Discovery cohort
Planets confirmed in 2012 at W. M. Keck Observatory (2 shown).
Host System: WISEP J121756.91+162640.2 A
Spectral Class
T-type brown dwarf
Effective Temperature
575 K — cooler than the Sun (5,778 K)
Estimated Age
6.00 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.091 R☉
Stellar Mass
0.029 M☉
Metallicity [Fe/H]
—