Key parameters at a glance

A radius of 1.78 Earth radii
A mass of 3.81 Earth masses
Surface gravity around 1.20 g
An orbital period of 3.601 days
Semi-major axis 0.0390 AU
Distance from Earth 52.27 light-years
Earth Similarity Index 0.829
Travel time at Voyager 1 speed 921,846 years
Almost certainly tidally locked to its host star given the close orbit

3 siblings around GJ 676 A

GJ 676 A d shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
GJ 676 A d this	Super-Earth	1.78	3.81	3.601	—	2012
GJ 676 A e	Sub-Neptune	2.47	6.67	35.474	—	2012
GJ 676 A b	Gas Giant	12.80	1,840.86	1,051.445	—	2010
GJ 676 A c	Gas Giant	12.30	4,288.14	13,921.423	—	2016

GJ 676 A d Planet Profile

Physical Specs

Radius

1.78 R⊕

Radius (Jupiter)

0.159 R♃

Mass

3.81 M⊕

Mass (Jupiter)

0.012 M♃

Density

3.72 g/cm³

Surface Gravity

1.20 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.829

HZ Position Unknown

Controversial No

Discovery

Year 2012

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#282of 1176

top 23.9%

This planet

1.78R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-1544 b 1.78 R⊕ Kepler-1003 b 1.78 R⊕ Kepler-881 b 1.78 R⊕

Metric	Earth	GJ 676 A d	Jupiter
Radius (R⊕)	1.00	1.78	11.21
Mass (M⊕)	1.00	3.81	317.83
Density (g/cm³)	5.51	3.72	1.33
Surface Gravity (g)	1.00	1.20	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	3.814 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 85647

TIC

TIC 369021303

Gaia DR2

Gaia DR2 5925209583053212800

Gaia DR3

Gaia DR3 5925209583053212800

System

GJ 676

Percentile among Super-Earth cohort

Radius 1.780 R⊕ · percentile 75 / cohort 1176

Mass 3.814 M⊕ · percentile 68 / cohort 1176

Orbital period 3.60 d · percentile 27 / cohort 1164

Distance 16.03 pc · percentile 3 / cohort 1171

ESI 0.829 · percentile 92 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

3.601 days

Semi-major axis

0.0390 AU

Eccentricity

0.192

Inclination

— °

Year Length

A year here lasts approximately 3.60 Earth days (1.0% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0390 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.829

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Anglada Escude Tuomi 2012

Instrument

HARPS Spectrograph

Publication

2012-12

Observation locale

Ground

Discovery cohort

Planets confirmed in 2012 at La Silla Observatory (11 shown).

GJ 667 C b · Sub-Neptune GJ 676 A e · Sub-Neptune HD 77338 b · Neptune-like HD 166724 b · Gas Giant HD 219077 b · Gas Giant HD 98649 b · Gas Giant HD 196067 b · Gas Giant HD 27631 b · Gas Giant HD 220689 b · Gas Giant GJ 3470 b · Neptune-like HD 106515 A b · Gas Giant

Host System: GJ 676 A

Spectral Class

M-type red dwarf

Effective Temperature

3,734 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.690 R☉

Stellar Mass

0.626 M☉

Metallicity [Fe/H]

0.23

Extended Stellar Properties

Surface gravity (log g)

4.620 dex

Stellar density

3.232 g/cm³

Systemic radial velocity

-39.04 km/s

Rotational v·sin i

1.60 km/s

Metallicity ratio

[Fe/H]

Distance

16.03 parsec

Light-years 52.27 ly

V-band magnitude

9.58 mag

Voyager-speed travel 921,846 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

62.365 mas

Total Proper Motion

317.084 mas/yr

PM Right Ascension

-257.87 mas/yr

PM Declination

-184.51 mas/yr

Galactic Cartesian (pc)

x = -0.081 · y = -0.615 · z = -0.784

Equatorial (J2000)

RA 262.54489° · Dec -51.63778°

Galactic ℓ, b

339.103° · -9.542°

Ecliptic λ, β

264.747° · -28.334°

HTM-20 index

-720701838

Observation Record

Photometric series

RV measurements

Archive notes