Key parameters at a glance

A radius of 1.33 Earth radii
A mass of 1.90 Earth masses
Surface gravity around 1.07 g
An orbital period of 0.926 days
Semi-major axis 0.0141 AU
Equilibrium temperature 940 K (667 °C)
Distance from Earth 39.28 light-years
Earth Similarity Index 0.324
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 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 806 b this	Super-Earth	1.33	1.90	0.926	940	2023
GJ 806 c	Sub-Neptune	2.28	5.80	6.641	490	2023

GJ 806 b Planet Profile

Physical Specs

Radius

1.33 R⊕

Radius (Jupiter)

0.119 R♃

Mass

1.90 M⊕

Mass (Jupiter)

0.006 M♃

Density

4.40 g/cm³

Surface Gravity

1.07 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.324

HZ Position Inner

Controversial No

Discovery

Year 2023

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1021of 1176

top 86.7%

This planet

1.33R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

K2-211 b 1.33 R⊕ Kepler-286 d 1.33 R⊕ Kepler-220 e 1.33 R⊕

Metric	Earth	GJ 806 b	Jupiter
Radius (R⊕)	1.00	1.33	11.21
Mass (M⊕)	1.00	1.90	317.83
Density (g/cm³)	5.51	4.40	1.33
Surface Gravity (g)	1.00	1.07	2.53
Insolation (S⊕)	1.00	130.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	1.900 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

HIP

HIP 102401

TIC

TIC 239332587

Gaia DR2

Gaia DR2 2070115588901082368

Gaia DR3

Gaia DR3 2070115588901082368

System

GJ 806

Percentile among Super-Earth cohort

Radius 1.331 R⊕ · percentile 13 / cohort 1176

Mass 1.900 M⊕ · percentile 1 / cohort 1176

Orbital period 0.93 d · percentile 5 / cohort 1164

Distance 12.04 pc · percentile 3 / cohort 1171

ESI 0.324 · percentile 43 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

0.926 days

Semi-major axis

0.0141 AU

Eccentricity

—

Inclination

87.70 °

Year Length

A year here lasts roughly 22.2 hours long at a mean orbital distance of 0.0141 AU.

Transit Fingerprint

Depth

0.095 %

Duration

0.930 h

Impact parameter b

0.300

Rp / R★

0.029400

Transit midpoint (BJD)

2,459,445.5737

Photometric dip

Transit produces a flux drop of 952 ppm lasting ≈ 0.93 h.

Extended Orbital Architecture

Planet / star radius ratio

0.029400

Semi-major axis / stellar radius

7.300

Impact parameter (b)

0.300

RV semi-amplitude (K)

2.250 m/s

Transit mid-time (BJD)

2,459,445.5737

Angular separation (arcsec)

1.17000

Eq. Temperature

940K

(667 °C)

Insolation (S⊕)

130.00

Earth = 1.00

Earth Similarity (ESI)

0.324

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.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Palle et al. 2023

Instrument

TESS CCD Array

Publication

2023-10

Observation locale

Space

Discovery cohort

Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-700 e · Rocky Terrestrial TOI-2095 c · Super-Earth TOI-715 b · Super-Earth TOI-2095 b · Super-Earth TOI-2096 c · Super-Earth TOI-1680 b · Super-Earth TOI-2096 b · Rocky Terrestrial TOI-904 c · Sub-Neptune TOI-1470 c · Sub-Neptune TOI-198 b · Super-Earth TOI-244 b · Super-Earth TOI-4184 b · Sub-Neptune

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]

Distance

12.04 parsec

Light-years 39.28 ly

V-band magnitude

10.79 mag

Voyager-speed travel 692,771 yr

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

Stellar spectra

Archive notes