Key parameters at a glance
- A radius of 2.28 Earth radii
- A mass of 5.80 Earth masses
- Surface gravity around 1.12 g
- An orbital period of 6.641 days
- Semi-major axis 0.0523 AU
- Equilibrium temperature 490 K (217 °C)
- Distance from Earth 39.28 light-years
- Earth Similarity Index 0.523
- Travel time at Voyager 1 speed 692,771 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around GJ 806
GJ 806 c 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 806 b | Super-Earth | 1.33 | 1.90 | 0.926 | 940 | 2023 |
| GJ 806 c this | Sub-Neptune | 2.28 | 5.80 | 6.641 | 490 | 2023 |
GJ 806 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1536of 1978
top 77.6%
This planet
2.28R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | GJ 806 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.28 | 11.21 |
| Mass (M⊕) | 1.00 | 5.80 | 317.83 |
| Density (g/cm³) | 5.51 | 2.69 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.12 | 2.53 |
| Insolation (S⊕) | 1.00 | 9.50 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 5.800 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HIP
HIP 102401
TIC
TIC 239332587
Gaia DR2
Gaia DR2 2070115588901082368
Gaia DR3
Gaia DR3 2070115588901082368
System
GJ 806
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.64 Earth days (1.8% of a terrestrial year) at a mean orbital distance of 0.0523 AU.
Extended Orbital Architecture
Semi-major axis / stellar radius
27.130
RV semi-amplitude (K)
3.550 m/s
Transit mid-time (BJD)
2,459,422.1820
Angular separation (arcsec)
4.34000
Eq. Temperature
490K
(217 °C)
Insolation (S⊕)
9.50
Earth = 1.00
Earth Similarity (ESI)
0.523
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Palle et al. 2023Instrument
Multiple Instruments
Publication
2023-10
Observation locale
Ground
Discovery cohort
Planets confirmed in 2023 at Multiple Observatories (12 shown).
Host System: GJ 806
Spectral Class
M-type red dwarf
Effective Temperature
3,600 K — cooler than the Sun (5,778 K)
Estimated Age
5.00 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.414 R☉
Stellar Mass
0.413 M☉
Metallicity [Fe/H]
-0.28
Extended Stellar Properties
Surface gravity (log g)
4.980 dex
Stellar density
8.600 g/cm³
Systemic radial velocity
-24.69 km/s
Rotational v·sin i
2.00 km/s
Rotation period
41.40 days
Activity index (log R'HK)
-4.923
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 8 bands
Astrometric Data
Parallax
82.997 mas
Total Proper Motion
511.804 mas/yr
PM Right Ascension
434.08 mas/yr
PM Declination
271.14 mas/yr
Galactic Cartesian (pc)
x = 0.470 · y = -0.536 · z = 0.701
Equatorial (J2000)
RA 311.26970° · Dec 44.50024°
Galactic ℓ, b
84.070° · 1.008°
Ecliptic λ, β
335.633° · 58.906°
HTM-20 index
-1579317321
Observation Record
Photometric series
1
Stellar spectra
2
Archive notes
2
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