Key parameters at a glance

A radius of 3.21 Earth radii
A mass of 10.40 Earth masses
Surface gravity around 1.01 g
An orbital period of 3.321 days
Equilibrium temperature 1,255 K (982 °C)
Distance from Earth 785.18 light-years
Earth Similarity Index 0.176
Travel time at Voyager 1 speed 13,846,616 years

TOI-4155 b Planet Profile

Physical Specs

Radius

3.21 R⊕

Radius (Jupiter)

0.286 R♃

Mass

10.40 M⊕

Mass (Jupiter)

0.033 M♃

Density

1.73 g/cm³

Surface Gravity

1.01 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.176

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

#339of 1978

top 17.1%

This planet

3.21R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-483 b 3.21 R⊕ Kepler-782 b 3.21 R⊕ MOA-2009-BLG-266L b 3.21 R⊕

Metric	Earth	TOI-4155 b	Jupiter
Radius (R⊕)	1.00	3.21	11.21
Mass (M⊕)	1.00	10.40	317.83
Density (g/cm³)	5.51	1.73	1.33
Surface Gravity (g)	1.00	1.01	2.53
Insolation (S⊕)	1.00	586.76	0.037

Star Catalogue Identifiers

TIC

TIC 467331291

Gaia DR2

Gaia DR2 2283857930619750144

Gaia DR3

Gaia DR3 2283857930619750144

System

TOI-4155

Percentile among Sub-Neptune cohort

Radius 3.210 R⊕ · percentile 83 / cohort 1978

Mass 10.400 M⊕ · percentile 76 / cohort 1978

Orbital period 3.32 d · percentile 6 / cohort 1946

Distance 240.74 pc · percentile 31 / cohort 1975

ESI 0.176 · percentile 4 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

3.321 days

Semi-major axis

— AU

Eccentricity

—

Inclination

88.84 °

Year Length

A year here lasts approximately 3.32 Earth days (0.9% of a terrestrial year).

Transit Fingerprint

Depth

0.094 %

Duration

2.487 h

Impact parameter b

0.210

Rp / R★

0.030930

Transit midpoint (BJD)

2,459,803.9384

Photometric dip

Transit produces a flux drop of 940 ppm lasting ≈ 2.49 h.

Extended Orbital Architecture

Planet / star radius ratio

0.030930

Semi-major axis / stellar radius

10.400

Impact parameter (b)

0.210

Transit mid-time (BJD)

2,459,803.9384

Eq. Temperature

1,255K

(982 °C)

Insolation (S⊕)

586.76

Earth = 1.00

Earth Similarity (ESI)

0.176

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Discovery Paper

Primary reference

Gomez Barrientos et al. 2025

Instrument

TESS CCD Array

Publication

2025-08

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-5728 b · 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

Host System: TOI-4155

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,724 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.950 R☉

Stellar Mass

1.160 M☉

Metallicity [Fe/H]

0.11

Extended Stellar Properties

Surface gravity (log g)

4.440 dex

Stellar density

1.898 g/cm³

Metallicity ratio

[m/H]

Distance

240.74 parsec

Light-years 785.18 ly

V-band magnitude

11.85 mag

Voyager-speed travel 13,846,616 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

4.125 mas

Total Proper Motion

41.869 mas/yr

PM Right Ascension

31.49 mas/yr

PM Declination

27.60 mas/yr

Galactic Cartesian (pc)

x = 0.175 · y = -0.120 · z = 0.977

Equatorial (J2000)

RA 325.63623° · Dec 77.73438°

Galactic ℓ, b

113.468° · 18.492°

Ecliptic λ, β

57.815° · 70.776°

HTM-20 index

-2000360003