Key parameters at a glance

A radius of 1.36 Earth radii
A mass of 2.47 Earth masses
Surface gravity around 1.34 g
An orbital period of 2.326 days
Semi-major axis 0.0208 AU
Equilibrium temperature 543 K (270 °C)
Distance from Earth 82.45 light-years
Earth Similarity Index 0.568
Travel time at Voyager 1 speed 1,453,976 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around TOI-771

TOI-771 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
TOI-771 b this	Super-Earth	1.36	2.47	2.326	543	2024
TOI-771 c	Super-Earth	1.50	2.87	7.610	365	2025

TOI-771 b Planet Profile

Physical Specs

Radius

1.36 R⊕

Radius (Jupiter)

0.121 R♃

Mass

2.47 M⊕

Mass (Jupiter)

0.008 M♃

Density

5.40 g/cm³

Surface Gravity

1.34 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.568

HZ Position Inner

Controversial No

Discovery

Year 2024

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#981of 1176

top 83.3%

This planet

1.36R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-1246 b 1.36 R⊕ Kepler-373 b 1.36 R⊕ Kepler-372 b 1.36 R⊕

Metric	Earth	TOI-771 b	Jupiter
Radius (R⊕)	1.00	1.36	11.21
Mass (M⊕)	1.00	2.47	317.83
Density (g/cm³)	5.51	5.40	1.33
Surface Gravity (g)	1.00	1.34	2.53
Insolation (S⊕)	1.00	14.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2.470 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 277634430

Gaia DR2

Gaia DR2 5229384714547758720

Gaia DR3

Gaia DR3 5229384714547758720

System

TOI-771

Percentile among Super-Earth cohort

Radius 1.360 R⊕ · percentile 16 / cohort 1176

Mass 2.470 M⊕ · percentile 18 / cohort 1176

Orbital period 2.33 d · percentile 14 / cohort 1164

Distance 25.28 pc · percentile 5 / cohort 1171

ESI 0.568 · percentile 79 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

2.326 days

Semi-major axis

0.0208 AU

Eccentricity

0.055

Inclination

89.30 °

Year Length

A year here lasts approximately 2.33 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0208 AU.

Transit Fingerprint

Depth

0.328 %

Duration

0.960 h

Impact parameter b

0.220

Rp / R★

0.053690

Transit midpoint (BJD)

2,458,572.4191

Photometric dip

Transit produces a flux drop of 3,280 ppm lasting ≈ 0.96 h.

Extended Orbital Architecture

Planet / star radius ratio

0.053690

Semi-major axis / stellar radius

18.900

Impact parameter (b)

0.220

RV semi-amplitude (K)

3.290 m/s

Transit mid-time (BJD)

2,458,572.4191

Long. of periastron (ω)

-130.00°

Angular separation (arcsec)

0.82300

Eq. Temperature

543K

(270 °C)

Insolation (S⊕)

14.00

Earth = 1.00

Earth Similarity (ESI)

0.568

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

Mistry et al. 2023

Instrument

TESS CCD Array

Publication

2023-11

Observation locale

Space

Discovery cohort

Planets confirmed in 2024 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

Gliese 12 b · Rocky Terrestrial TOI-6002 b · Super-Earth TOI-5713 b · Super-Earth TOI-4336 A b · Sub-Neptune TOI-406.01 · Sub-Neptune TOI-1224 c · Sub-Neptune LHS 1678 d · Rocky Terrestrial TOI-2088 b · Sub-Neptune TOI-2120 b · Sub-Neptune TOI-1806.01 · Sub-Neptune TOI-4633 c · Sub-Neptune TOI-260 b · Super-Earth

Host System: TOI-771

Spectral Class

M-type red dwarf

Effective Temperature

3,370 K — cooler than the Sun (5,778 K)

Estimated Age

6.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.232 R☉

Stellar Mass

0.220 M☉

Metallicity [Fe/H]

-0.13

Extended Stellar Properties

Surface gravity (log g)

4.800 dex

Stellar density

23.685 g/cm³

Systemic radial velocity

-5.90 km/s

Rotation period

98.00 days

Activity index (log R'HK)

-6.360

Metallicity ratio

[Fe/H]

Distance

25.28 parsec

Light-years 82.45 ly

V-band magnitude

14.89 mag

Voyager-speed travel 1,453,976 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

39.530 mas

Total Proper Motion

86.005 mas/yr

PM Right Ascension

39.48 mas/yr

PM Declination

-76.41 mas/yr

Galactic Cartesian (pc)

x = -0.281 · y = 0.080 · z = -0.956

Equatorial (J2000)

RA 164.11389° · Dec -72.98517°

Galactic ℓ, b

294.660° · -11.987°

Ecliptic λ, β

227.472° · -65.393°

HTM-20 index

-1232841563