Key parameters at a glance
- A radius of 13.00 Earth radii
- A mass of 3,000.00 Earth masses
- Surface gravity around 17.75 g
- An orbital period of 69,000.000 days
- Semi-major axis 38.0000 AU
- Equilibrium temperature 1,200 K (927 °C)
- Distance from Earth 134.52 light-years
- Earth Similarity Index 0.134
- Travel time at Voyager 1 speed 2,372,262 years
3 siblings around HR 8799
HR 8799 c shares its host star with 3 other confirmed planets. Side-by-side measurements below.
HR 8799 c Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#960of 1771
top 54.2%
This planet
13.00R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HR 8799 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 13.00 | 11.21 |
| Mass (M⊕) | 1.00 | 3,000.00 | 317.83 |
| Density (g/cm³) | 5.51 | 7.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 17.75 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 3,000.000 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HD
HD 218396
HIP
HIP 114189
TIC
TIC 245368902
Gaia DR2
Gaia DR2 2832463659640297472
Gaia DR3
Gaia DR3 2832463659640297472
System
HR 8799
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts about 188.91 Earth years on a highly eccentric trajectory at a mean orbital distance of 38.0000 AU.
Eq. Temperature
1,200K
(927 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.134
0 = alien, 1 = Earth-identical
Insufficient insolation data — the dayside is scorched.
Detection Signatures
Astrometry
Positional wobble of the host star was measured.
Direct imaging
The planet has been imaged directly (rare).
Discovery Paper
Primary reference
Marois et al. 2008Instrument
NIRI Camera
Publication
2008-11
Observation locale
Ground
Discovery cohort
Planets confirmed in 2008 at Gemini Observatory (2 shown).
Host System: HR 8799
Spectral Class
A-type white
Effective Temperature
7,205 K — hotter than the Sun (5,778 K)
Estimated Age
0.06 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.493 R☉
Stellar Mass
1.500 M☉
Metallicity [Fe/H]
-0.47
Extended Stellar Properties
Surface gravity (log g)
4.297 dex
Stellar density
0.682 g/cm³
Rotational v·sin i
34.79 km/s
Metallicity ratio
[M/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
24.218 mas
Total Proper Motion
119.069 mas/yr
PM Right Ascension
108.30 mas/yr
PM Declination
-49.48 mas/yr
Galactic Cartesian (pc)
x = 0.908 · y = -0.212 · z = 0.361
Equatorial (J2000)
RA 346.87015° · Dec 21.13404°
Galactic ℓ, b
92.765° · -35.576°
Ecliptic λ, β
356.784° · 24.524°
HTM-20 index
590321788
Similar Worlds
HR 8799 b
Gas Giant · A-type white
Radius 13.00 R⊕ · 134.5 ly
HR 8799 d
Gas Giant · A-type white
Radius 13.00 R⊕ · 134.5 ly
HD 95086 b
Gas Giant · A-type white
Radius 12.90 R⊕ · 281.2 ly
HR 8799 e
Gas Giant · A-type white
Radius 13.11 R⊕ · 134.5 ly
WD 0806-661 b
Gas Giant · A-type white
Radius 12.60 R⊕ · 62.8 ly
AB Aur b
Gas Giant · A-type white
Radius 12.50 R⊕ · 528.8 ly