Key parameters at a glance

A radius of 1.31 Earth radii
A mass of 2.27 Earth masses
Surface gravity around 1.32 g
An orbital period of 11.498 days
Equilibrium temperature 382 K (109 °C)
Distance from Earth 178.42 light-years
Earth Similarity Index 0.773
Travel time at Voyager 1 speed 3,146,472 years
Almost certainly tidally locked to its host star given the close orbit

TOI-5728 b Planet Profile

Physical Specs

Radius

1.31 R⊕

Radius (Jupiter)

0.117 R♃

Mass

2.27 M⊕

Mass (Jupiter)

0.007 M♃

Density

5.55 g/cm³

Surface Gravity

1.32 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.773

HZ Position Inner

Controversial No

Discovery

Year 2025

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1072of 1176

top 91.1%

This planet

1.31R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-374 d 1.31 R⊕ Kepler-1298 b 1.31 R⊕ Kepler-62 b 1.31 R⊕

Metric	Earth	TOI-5728 b	Jupiter
Radius (R⊕)	1.00	1.31	11.21
Mass (M⊕)	1.00	2.27	317.83
Density (g/cm³)	5.51	5.55	1.33
Surface Gravity (g)	1.00	1.32	2.53
Insolation (S⊕)	1.00	3.51	0.037

Star Catalogue Identifiers

TIC

TIC 219875976

Gaia DR2

Gaia DR2 1637184500366418432

Gaia DR3

Gaia DR3 1637184500366418432

System

TOI-5728

Percentile among Super-Earth cohort

Radius 1.310 R⊕ · percentile 8 / cohort 1176

Mass 2.270 M⊕ · percentile 8 / cohort 1176

Orbital period 11.50 d · percentile 68 / cohort 1164

Distance 54.70 pc · percentile 11 / cohort 1171

ESI 0.773 · percentile 88 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

11.498 days

Semi-major axis

— AU

Eccentricity

—

Inclination

89.83 °

Year Length

A year here lasts approximately 11.50 Earth days (3.1% of a terrestrial year).

Transit Fingerprint

Depth

0.084 %

Duration

2.391 h

Impact parameter b

0.117

Rp / R★

0.031900

Transit midpoint (BJD)

2,458,685.0868

Photometric dip

Transit produces a flux drop of 843 ppm lasting ≈ 2.39 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031900

Semi-major axis / stellar radius

39.900

Impact parameter (b)

0.117

Transit mid-time (BJD)

2,458,685.0868

Eq. Temperature

382K

(109 °C)

Insolation (S⊕)

3.51

Earth = 1.00

Earth Similarity (ESI)

0.773

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

Gomez Barrientos et al. 2025

Instrument

TESS CCD Array

Publication

2025-12

Observation locale

Space

Discovery cohort

Planets confirmed in 2025 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-1266 d · Super-Earth TOI-2267 c · Rocky Terrestrial TOI-5799 c · Super-Earth TOI-5716 b · Rocky Terrestrial TOI-7166 b · Sub-Neptune TOI-2267 b · Rocky Terrestrial TOI-2093 c · Sub-Neptune TOI-2267 d · Super-Earth TOI-5489 c · Super-Earth TOI-1743 b · Super-Earth TOI-4364 b · Sub-Neptune HD 35843 c · Sub-Neptune

Host System: TOI-5728

Spectral Class

M-type red dwarf

Effective Temperature

3,419 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.370 R☉

Stellar Mass

0.360 M☉

Metallicity [Fe/H]

-0.12

Extended Stellar Properties

Surface gravity (log g)

4.849 dex

Stellar density

9.658 g/cm³

Systemic radial velocity

-6.81 km/s

Metallicity ratio

[Fe/H]

Distance

54.70 parsec

Light-years 178.42 ly

V-band magnitude

15.02 mag

Voyager-speed travel 3,146,472 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

18.251 mas

Total Proper Motion

171.823 mas/yr

PM Right Ascension

64.06 mas/yr

PM Declination

159.44 mas/yr

Galactic Cartesian (pc)

x = -0.064 · y = -0.376 · z = 0.924

Equatorial (J2000)

RA 260.35094° · Dec 67.55042°

Galactic ℓ, b

97.913° · 33.472°

Ecliptic λ, β

160.844° · 86.115°

HTM-20 index

-573115958