Key parameters at a glance

A radius of 1.53 Earth radii
A mass of 2.96 Earth masses
Surface gravity around 1.26 g
An orbital period of 2.378 days
Semi-major axis 0.0290 AU
Equilibrium temperature 829 K (556 °C)
Distance from Earth 36.21 light-years
Earth Similarity Index 0.362
Travel time at Voyager 1 speed 638,543 years
Almost certainly tidally locked to its host star given the close orbit

GJ 740 b Planet Profile

Physical Specs

Radius

1.53 R⊕

Radius (Jupiter)

0.137 R♃

Mass

2.96 M⊕

Mass (Jupiter)

0.009 M♃

Density

4.54 g/cm³

Surface Gravity

1.26 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.362

HZ Position Inner

Controversial No

Discovery

Year 2021

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#687of 1176

top 58.3%

This planet

1.53R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-228 b 1.53 R⊕ Kepler-147 b 1.53 R⊕ Kepler-296 e 1.53 R⊕

Metric	Earth	GJ 740 b	Jupiter
Radius (R⊕)	1.00	1.53	11.21
Mass (M⊕)	1.00	2.96	317.83
Density (g/cm³)	5.51	4.54	1.33
Surface Gravity (g)	1.00	1.26	2.53
Insolation (S⊕)	1.00	79.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	2.960 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 176029

HIP

HIP 93101

TIC

TIC 227642705

Gaia DR2

Gaia DR2 4282578724832056576

Gaia DR3

Gaia DR3 4282578724832056576

System

GJ 740

Percentile among Super-Earth cohort

Radius 1.530 R⊕ · percentile 40 / cohort 1176

Mass 2.960 M⊕ · percentile 37 / cohort 1176

Orbital period 2.38 d · percentile 15 / cohort 1164

Distance 11.10 pc · percentile 2 / cohort 1171

ESI 0.362 · percentile 53 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

2.378 days

Semi-major axis

0.0290 AU

Eccentricity

0.240

Inclination

— °

Year Length

A year here lasts approximately 2.38 Earth days (0.7% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0290 AU.

Eq. Temperature

829K

(556 °C)

Insolation (S⊕)

79.00

Earth = 1.00

Earth Similarity (ESI)

0.362

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

Toledo Padr Oacute N et al. 2021

Instrument

Multiple Instruments

Publication

2021-04

Observation locale

Ground

Discovery cohort

Planets confirmed in 2021 at Multiple Observatories (12 shown).

L 98-59 e · Super-Earth GJ 393 b · Rocky Terrestrial HD 168009 b · Sub-Neptune HD 164922 e · Sub-Neptune HD 95735 c · Sub-Neptune HD 141004 b · Sub-Neptune HD 107148 c · Neptune-like TOI-178 f · Sub-Neptune TYC 0434-04538-1 b · Gas Giant HIP 56640 b · Gas Giant HD 137496 c · Gas Giant HD 156668 c · Neptune-like

Host System: GJ 740

Spectral Class

M-type red dwarf

Effective Temperature

3,913 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.560 R☉

Stellar Mass

0.580 M☉

Metallicity [Fe/H]

0.08

Extended Stellar Properties

Surface gravity (log g)

4.680 dex

Stellar density

4.012 g/cm³

Systemic radial velocity

9.50 km/s

Rotational v·sin i

0.92 km/s

Rotation period

35.56 days

Metallicity ratio

[Fe/H]

Distance

11.10 parsec

Light-years 36.21 ly

V-band magnitude

9.22 mag

Voyager-speed travel 638,543 yr

Multi-band Host Photometry — 8 bands

Astrometric Data

Parallax

90.048 mas

Total Proper Motion

1,236.156 mas/yr

PM Right Ascension

-196.30 mas/yr

PM Declination

-1,220.47 mas/yr

Galactic Cartesian (pc)

x = 0.249 · y = -0.963 · z = 0.103

Equatorial (J2000)

RA 284.49972° · Dec 5.90287°

Galactic ℓ, b

38.932° · 1.235°

Ecliptic λ, β

286.462° · 28.517°

HTM-20 index

-1605257100