Key parameters at a glance
- A radius of 13.30 Earth radii
- A mass of 794.50 Earth masses
- Surface gravity around 4.49 g
- An orbital period of 695.690 days
- Semi-major axis 1.1380 AU
- Distance from Earth 49.57 light-years
- Earth Similarity Index 0.382
- Travel time at Voyager 1 speed 874,084 years
1 sibling around GJ 317
GJ 317 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| GJ 317 b this | Gas Giant | 13.30 | 794.50 | 695.690 | — | 2007 |
| GJ 317 c | Gas Giant | 13.60 | 454.49 | 6,500.000 | — | 2018 |
GJ 317 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#793of 1771
top 44.7%
This planet
13.30R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | GJ 317 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 13.30 | 11.21 |
| Mass (M⊕) | 1.00 | 794.50 | 317.83 |
| Density (g/cm³) | 5.51 | 1.86 | 1.33 |
| Surface Gravity (g) | 1.00 | 4.49 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 794.500 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 536.494 M⊕ | Lower bound from radial-velocity fitting. |
| Computed mass | 809.060 M⊕ | Model-computed mass (e.g. from mass-radius relation). |
Star Catalogue Identifiers
TIC
TIC 118608254
Gaia DR2
Gaia DR2 5701750711020088192
Gaia DR3
Gaia DR3 5701750715316821248
System
GJ 317
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts about 1.90 Earth years on a nearly circular orbit at a mean orbital distance of 1.1380 AU.
Extended Orbital Architecture
RV semi-amplitude (K)
71.390 m/s
Transit mid-time (BJD)
2,458,089.4000
Long. of periastron (ω)
11.30°
Angular separation (arcsec)
74.90000
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.382
0 = alien, 1 = Earth-identical
Discovery Paper
Primary reference
Johnson et al. 2007Instrument
HIRES Spectrometer
Publication
2007-11
Observation locale
Ground
Discovery cohort
Planets confirmed in 2007 at W. M. Keck Observatory (7 shown).
Host System: GJ 317
Spectral Class
M-type red dwarf
Effective Temperature
3,496 K — cooler than the Sun (5,778 K)
Estimated Age
5.00 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.403 R☉
Stellar Mass
0.402 M☉
Metallicity [Fe/H]
-0.02
Extended Stellar Properties
Surface gravity (log g)
4.822 dex
Stellar density
7.648 g/cm³
Systemic radial velocity
87.80 km/s
Rotational v·sin i
2.50 km/s
Rotation period
57.50 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
65.774 mas
Total Proper Motion
928.232 mas/yr
PM Right Ascension
-461.16 mas/yr
PM Declination
805.57 mas/yr
Galactic Cartesian (pc)
x = -0.593 · y = 0.700 · z = -0.398
Equatorial (J2000)
RA 130.24453° · Dec -23.45281°
Galactic ℓ, b
246.795° · 11.190°
Ecliptic λ, β
140.752° · -40.068°
HTM-20 index
-115598586
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