Key parameters at a glance

A radius of 3.76 Earth radii
A mass of 13.60 Earth masses
Surface gravity around 0.96 g
An orbital period of 5.099 days
Semi-major axis 0.0483 AU
Equilibrium temperature 604 K (330 °C)
Distance from Earth 107.71 light-years
Earth Similarity Index 0.354
Travel time at Voyager 1 speed 1,899,410 years
Almost certainly tidally locked to its host star given the close orbit

TOI-620 b Planet Profile

Physical Specs

Radius

3.76 R⊕

Radius (Jupiter)

0.335 R♃

Mass

13.60 M⊕

Mass (Jupiter)

0.043 M♃

Density

1.41 g/cm³

Surface Gravity

0.96 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.354

HZ Position Inner

Controversial No

Discovery

Year 2022

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#68of 1978

top 3.4%

This planet

3.76R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

KMT-2023-BLG-1431L b 3.76 R⊕ HD 95735 c 3.76 R⊕ Kepler-160 c 3.76 R⊕

Metric	Earth	TOI-620 b	Jupiter
Radius (R⊕)	1.00	3.76	11.21
Mass (M⊕)	1.00	13.60	317.83
Density (g/cm³)	5.51	1.41	1.33
Surface Gravity (g)	1.00	0.96	2.53
Insolation (S⊕)	1.00	20.80	0.037

Star Catalogue Identifiers

TIC

TIC 296739893

Gaia DR2

Gaia DR2 5738284016370287616

Gaia DR3

Gaia DR3 5738284016370287616

System

TOI-620

Percentile among Sub-Neptune cohort

Radius 3.760 R⊕ · percentile 96 / cohort 1978

Mass 13.600 M⊕ · percentile 89 / cohort 1978

Orbital period 5.10 d · percentile 12 / cohort 1946

Distance 33.02 pc · percentile 8 / cohort 1975

ESI 0.354 · percentile 42 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.099 days

Semi-major axis

0.0483 AU

Eccentricity

0.220

Inclination

87.47 °

Year Length

A year here lasts approximately 5.10 Earth days (1.4% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0483 AU.

Transit Fingerprint

Depth

0.393 %

Duration

1.360 h

Impact parameter b

0.887

Rp / R★

0.062700

Transit midpoint (BJD)

2,458,992.1972

Photometric dip

Transit produces a flux drop of 3,930 ppm lasting ≈ 1.36 h.

Extended Orbital Architecture

Planet / star radius ratio

0.062700

Semi-major axis / stellar radius

18.870

Impact parameter (b)

0.887

Transit mid-time (BJD)

2,458,992.1972

Long. of periastron (ω)

-84.00°

Angular separation (arcsec)

1.46000

Eq. Temperature

604K

(330 °C)

Insolation (S⊕)

20.80

Earth = 1.00

Earth Similarity (ESI)

0.354

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

Reefe et al. 2022

Instrument

TESS CCD Array

Publication

2022-04

Observation locale

Space

Discovery cohort

Planets confirmed in 2022 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-1452 b · Super-Earth TOI-712 d · Sub-Neptune TOI-1468 c · Sub-Neptune TOI-2136 b · Sub-Neptune LTT 1445 A c · Rocky Terrestrial TOI-712 c · Sub-Neptune LP 890-9 b · Super-Earth TOI-2081 b · Sub-Neptune GJ 3929 b · Rocky Terrestrial HD 260655 c · Super-Earth HD 73583 c · Sub-Neptune TOI-1759 b · Sub-Neptune

Host System: TOI-620

Spectral Class

M-type red dwarf

Effective Temperature

3,708 K — cooler than the Sun (5,778 K)

Estimated Age

7.20 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.550 R☉

Stellar Mass

0.577 M☉

Metallicity [Fe/H]

0.35

Extended Stellar Properties

Surface gravity (log g)

4.718 dex

Stellar density

4.890 g/cm³

Rotational v·sin i

3.00 km/s

Rotation period

8.99 days

Metallicity ratio

[Fe/H]

Distance

33.02 parsec

Light-years 107.71 ly

V-band magnitude

12.26 mag

Voyager-speed travel 1,899,410 yr

Multi-band Host Photometry — 7 bands

Astrometric Data

Parallax

30.253 mas

Total Proper Motion

391.501 mas/yr

PM Right Ascension

35.87 mas/yr

PM Declination

-389.85 mas/yr

Galactic Cartesian (pc)

x = -0.772 · y = 0.599 · z = -0.211

Equatorial (J2000)

RA 142.17345° · Dec -12.16717°

Galactic ℓ, b

244.790° · 27.071°

Ecliptic λ, β

148.874° · -25.584°

HTM-20 index

193407047