Confirmed Exoplanet Discovered 2025

TOI-283 b

A sub-neptune orbiting the k-type orange TOI-283, located approximately 269.7 light-years from Earth.

Key parameters at a glance

  • A radius of 2.34 Earth radii
  • A mass of 6.54 Earth masses
  • Surface gravity around 1.19 g
  • An orbital period of 17.617 days
  • Semi-major axis 0.1230 AU
  • Equilibrium temperature 661 K (388 °C)
  • Distance from Earth 269.74 light-years
  • Earth Similarity Index 0.396
  • Travel time at Voyager 1 speed 4,756,781 years
  • Almost certainly tidally locked to its host star given the close orbit

TOI-283 b Planet Profile

Physical Specs

Radius
2.34 R⊕
Radius (Jupiter)
0.209 R♃
Mass
6.54 M⊕
Mass (Jupiter)
0.021 M♃
Density
2.81 g/cm³
Surface Gravity
1.19 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.396
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

#1429of 1978

top 72.2%

This planet

2.34R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth TOI-283 b Jupiter
Radius (R⊕)1.002.3411.21
Mass (M⊕)1.006.54317.83
Density (g/cm³)5.512.811.33
Surface Gravity (g)1.001.192.53
Insolation (S⊕)1.0030.400.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 6.540 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 382626661

Gaia DR2

Gaia DR2 5275527747224425344

Gaia DR3

Gaia DR3 5275527747228841344

System

TOI-283

Percentile among Sub-Neptune cohort

Radius 2.340 R⊕ · percentile 27 / cohort 1978
Mass 6.540 M⊕ · percentile 34 / cohort 1978
Orbital period 17.62 d · percentile 58 / cohort 1946
Distance 82.70 pc · percentile 18 / cohort 1975
ESI 0.396 · percentile 51 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
17.617 days
Semi-major axis
0.1230 AU
Eccentricity
0.000
Inclination
89.12 °

Year Length

A year here lasts approximately 17.62 Earth days (4.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1230 AU.

Transit Fingerprint

Depth

0.072 %

Duration

3.615 h

Impact parameter b

0.476

Rp / R★

0.025200

Transit midpoint (BJD)

2,459,549.0822

Photometric dip

Transit produces a flux drop of 722 ppm lasting ≈ 3.62 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025200

Semi-major axis / stellar radius

31.120

Impact parameter (b)

0.476

RV semi-amplitude (K)

1.860 m/s

Transit mid-time (BJD)

2,459,549.0822

Long. of periastron (ω)

90.00°

Angular separation (arcsec)

1.49000

Eq. Temperature

661K

(388 °C)

Insolation (S⊕)

30.40

Earth = 1.00

Earth Similarity (ESI)

0.396

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

Murgas et al. 2025

Instrument

TESS CCD Array

Publication

2025-10

Observation locale

Space

Host System: TOI-283

Spectral Class

K-type orange

Effective Temperature

5,213 K — cooler than the Sun (5,778 K)

Estimated Age

10.40 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.850 R☉

Stellar Mass

0.800 M☉

Metallicity [Fe/H]

-0.09

Extended Stellar Properties

Surface gravity (log g)

4.500 dex

Stellar density

1.830 g/cm³

Systemic radial velocity

-12.64 km/s

Rotation period

30.00 days

Activity index (log R'HK)

-4.920

Metallicity ratio

[Fe/H]

Distance
82.70 parsec
Light-years 269.74 ly
V-band magnitude
10.41 mag
Voyager-speed travel 4,756,781 yr

Multi-band Host Photometry — 11 bands

8.411.211.24B10.41V10.20Gaia9.68TESS9.00J8.55H8.52K8.42W18.48W28.46W38.48W4

Astrometric Data

Parallax

12.063 mas

Total Proper Motion

34.609 mas/yr

PM Right Ascension

-30.77 mas/yr

PM Declination

15.84 mas/yr

Galactic Cartesian (pc)

x = -0.199 · y = 0.365 · z = -0.910

Equatorial (J2000)

RA 118.56931° · Dec -65.44148°

Galactic ℓ, b

278.003° · -18.335°

Ecliptic λ, β

187.703° · -78.430°

HTM-20 index

584384701

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