Key parameters at a glance

A radius of 1.23 Earth radii
A mass of 2.02 Earth masses
Surface gravity around 1.34 g
An orbital period of 5.364 days
Semi-major axis 0.0328 AU
Distance from Earth 17.53 light-years
Earth Similarity Index 0.936
Travel time at Voyager 1 speed 309,148 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around GJ 3323

GJ 3323 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 3323 b this	Rocky Terrestrial	1.23	2.02	5.364	—	2017
GJ 3323 c	Super-Earth	1.32	2.31	40.540	—	2017

GJ 3323 b Planet Profile

Physical Specs

Radius

1.23 R⊕

Radius (Jupiter)

0.109 R♃

Mass

2.02 M⊕

Mass (Jupiter)

0.006 M♃

Density

5.96 g/cm³

Surface Gravity

1.34 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.936

HZ Position Inner

Controversial No

Discovery

Year 2017

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#17of 570

top 2.8%

This planet

1.23R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-252 b 1.23 R⊕ Kepler-271 b 1.23 R⊕ Kepler-197 c 1.23 R⊕

Metric	Earth	GJ 3323 b	Jupiter
Radius (R⊕)	1.00	1.23	11.21
Mass (M⊕)	1.00	2.02	317.83
Density (g/cm³)	5.51	5.96	1.33
Surface Gravity (g)	1.00	1.34	2.53
Insolation (S⊕)	1.00	2.58	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	2.020 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 43605290

Gaia DR2

Gaia DR2 3187115498866675456

Gaia DR3

Gaia DR3 3187115498866675456

System

GJ 3323

Percentile among Rocky Terrestrial cohort

Radius 1.230 R⊕ · percentile 94 / cohort 570

Mass 2.020 M⊕ · percentile 86 / cohort 570

Orbital period 5.36 d · percentile 57 / cohort 567

Distance 5.37 pc · percentile 4 / cohort 566

ESI 0.936 · percentile 92 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

5.364 days

Semi-major axis

0.0328 AU

Eccentricity

0.230

Inclination

— °

Year Length

A year here lasts approximately 5.36 Earth days (1.5% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0328 AU.

Eq. Temperature

—

Insolation (S⊕)

2.58

Earth = 1.00

Earth Similarity (ESI)

0.936

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water). Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Astudillo Defru et al. 2017

Instrument

HARPS Spectrograph

Publication

2017-06

Observation locale

Ground

Discovery cohort

Planets confirmed in 2017 at La Silla Observatory (12 shown).

GJ 273 c · Rocky Terrestrial Ross 128 b · Rocky Terrestrial GJ 3138 b · Rocky Terrestrial GJ 3323 c · Super-Earth GJ 273 b · Super-Earth GJ 3293 e · Super-Earth YZ Cet d · Rocky Terrestrial GJ 3138 c · Super-Earth YZ Cet c · Rocky Terrestrial GJ 3293 d · Sub-Neptune YZ Cet b · Rocky Terrestrial GJ 3138 d · Sub-Neptune

Host System: GJ 3323

Spectral Class

M-type red dwarf

Effective Temperature

3,159 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.119 R☉

Stellar Mass

0.164 M☉

Metallicity [Fe/H]

-0.27

Extended Stellar Properties

Systemic radial velocity

42.45 km/s

Rotation period

33.00 days

Metallicity ratio

[Fe/H]

Distance

5.37 parsec

Light-years 17.53 ly

V-band magnitude

12.57 mag

Voyager-speed travel 309,148 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

186.023 mas

Total Proper Motion

767.779 mas/yr

PM Right Ascension

-551.72 mas/yr

PM Declination

-533.94 mas/yr

Galactic Cartesian (pc)

x = 0.249 · y = 0.961 · z = -0.121

Equatorial (J2000)

RA 75.48688° · Dec -6.94851°

Galactic ℓ, b

206.432° · -27.474°

Ecliptic λ, β

73.379° · -29.554°

HTM-20 index

-1460020599