Confirmed Exoplanet Discovered 2025

TOI-333 b

A neptune-like orbiting the f-type yellow-white TOI-333, located approximately 1,148.9 light-years from Earth.

Key parameters at a glance

  • A radius of 4.26 Earth radii
  • A mass of 20.10 Earth masses
  • Surface gravity around 1.11 g
  • An orbital period of 3.785 days
  • Semi-major axis 0.0490 AU
  • Equilibrium temperature 1,445 K (1172 °C)
  • Distance from Earth 1,148.95 light-years
  • Earth Similarity Index 0.136
  • Travel time at Voyager 1 speed 20,261,670 years

TOI-333 b Planet Profile

Physical Specs

Radius
4.26 R⊕
Radius (Jupiter)
0.380 R♃
Mass
20.10 M⊕
Mass (Jupiter)
0.063 M♃
Density
1.42 g/cm³
Surface Gravity
1.11 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.136
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

#506of 574

top 88.0%

This planet

4.26R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Metric Earth TOI-333 b Jupiter
Radius (R⊕)1.004.2611.21
Mass (M⊕)1.0020.10317.83
Density (g/cm³)5.511.421.33
Surface Gravity (g)1.001.112.53
Insolation (S⊕)1.00650.500.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 20.100 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 224245334

Gaia DR2

Gaia DR2 6535747220036134272

Gaia DR3

Gaia DR3 6535747220036134272

System

TOI-333

Percentile among Neptune-like cohort

Radius 4.260 R⊕ · percentile 11 / cohort 574
Mass 20.100 M⊕ · percentile 29 / cohort 574
Orbital period 3.79 d · percentile 10 / cohort 524
Distance 352.27 pc · percentile 51 / cohort 572
ESI 0.136 · percentile 9 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
3.785 days
Semi-major axis
0.0490 AU
Eccentricity
0.000
Inclination
89.26 °

Year Length

A year here lasts approximately 3.79 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0490 AU.

Transit Fingerprint

Depth

0.134 %

Duration

3.200 h

Impact parameter b

0.120

Rp / R★

0.035000

Transit midpoint (BJD)

2,458,355.5759

Photometric dip

Transit produces a flux drop of 1,339 ppm lasting ≈ 3.20 h.

Extended Orbital Architecture

Planet / star radius ratio

0.035000

Semi-major axis / stellar radius

9.260

Impact parameter (b)

0.120

RV semi-amplitude (K)

7.900 m/s

Transit mid-time (BJD)

2,458,355.5759

Long. of periastron (ω)

90.00°

Angular separation (arcsec)

0.13900

Eq. Temperature

1,445K

(1172 °C)

Insolation (S⊕)

650.50

Earth = 1.00

Earth Similarity (ESI)

0.136

0 = alien, 1 = Earth-identical

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

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

Alves et al. 2025

Instrument

TESS CCD Array

Publication

2025-11

Observation locale

Space

Host System: TOI-333

Spectral Class

F-type yellow-white

Effective Temperature

6,241 K — hotter than the Sun (5,778 K)

Estimated Age

1.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.100 R☉

Stellar Mass

1.200 M☉

Metallicity [Fe/H]

0.01

Extended Stellar Properties

Surface gravity (log g)

4.410 dex

Stellar density

1.050 g/cm³

Rotational v·sin i

6.18 km/s

Rotation period

9.01 days

Metallicity ratio

[Fe/H]

Distance
352.27 parsec
Light-years 1,148.95 ly
V-band magnitude
12.21 mag
Voyager-speed travel 20,261,670 yr

Multi-band Host Photometry — 11 bands

9.112.712.74B12.21V11.90Gaia11.52TESS10.98J10.76H10.68K10.65W110.70W210.70W39.08W4

Astrometric Data

Parallax

2.810 mas

Total Proper Motion

16.797 mas/yr

PM Right Ascension

16.70 mas/yr

PM Declination

1.79 mas/yr

Galactic Cartesian (pc)

x = 0.748 · y = -0.087 · z = -0.658

Equatorial (J2000)

RA 353.35750° · Dec -41.17152°

Galactic ℓ, b

346.699° · -68.698°

Ecliptic λ, β

335.432° · -34.705°

HTM-20 index

-2040837955

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