Confirmed Exoplanet Discovered 2025

TOI-3288 b

A gas giant orbiting the m-type red dwarf TOI-3288, located approximately 653.9 light-years from Earth.

Key parameters at a glance

  • A radius of 12.24 Earth radii
  • A mass of 536.18 Earth masses
  • Surface gravity around 3.58 g
  • An orbital period of 1.434 days
  • Semi-major axis 0.0229 AU
  • Equilibrium temperature 973 K (700 °C)
  • Distance from Earth 653.94 light-years
  • Earth Similarity Index 0.164
  • Travel time at Voyager 1 speed 11,532,280 years
  • Almost certainly tidally locked to its host star given the close orbit

TOI-3288 b Planet Profile

Physical Specs

Radius
12.24 R⊕
Radius (Jupiter)
1.092 R♃
Mass
536.18 M⊕
Mass (Jupiter)
1.687 M♃
Density
1.60 g/cm³
Surface Gravity
3.58 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.164
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

#1397of 1771

top 78.8%

This planet

12.24R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth TOI-3288 b Jupiter
Radius (R⊕)1.0012.2411.21
Mass (M⊕)1.00536.18317.83
Density (g/cm³)5.511.601.33
Surface Gravity (g)1.003.582.53
Insolation (S⊕)1.00213.800.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 536.177 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 79920467

Gaia DR2

Gaia DR2 6685431748042347776

Gaia DR3

Gaia DR3 6685431748042347776

System

TOI-3288

Percentile among Gas Giant cohort

Radius 12.240 R⊕ · percentile 21 / cohort 1771
Mass 536.177 M⊕ · percentile 50 / cohort 1747
Orbital period 1.43 d · percentile 3 / cohort 1533
Distance 200.50 pc · percentile 50 / cohort 1759
ESI 0.164 · percentile 38 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
1.434 days
Semi-major axis
0.0229 AU
Eccentricity
0.021
Inclination
89.00 °

Year Length

A year here lasts approximately 1.43 Earth days (0.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0228 AU.

Transit Fingerprint

Depth

3.136 %

Duration

41.690 h

Impact parameter b

0.128

Rp / R★

0.167010

Transit midpoint (BJD)

2,460,343.9069

Photometric dip

Transit produces a flux drop of 31,360 ppm lasting ≈ 41.69 h.

Extended Orbital Architecture

Planet / star radius ratio

0.167010

Semi-major axis / stellar radius

7.330

Impact parameter (b)

0.128

RV semi-amplitude (K)

433.000 m/s

Transit mid-time (BJD)

2,460,343.9069

Long. of periastron (ω)

174.00°

Angular separation (arcsec)

0.11400

Eq. Temperature

973K

(700 °C)

Insolation (S⊕)

213.80

Earth = 1.00

Earth Similarity (ESI)

0.164

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

Frensch et al. 2025

Instrument

TESS CCD Array

Publication

2025-10

Observation locale

Space

Host System: TOI-3288

Spectral Class

M-type red dwarf

Effective Temperature

4,072 K — cooler than the Sun (5,778 K)

Estimated Age

Stellar Radius

0.672 R☉

Stellar Mass

0.643 M☉

Metallicity [Fe/H]

0.65

Extended Stellar Properties

Surface gravity (log g)

4.592 dex

Stellar density

3.240 g/cm³

Metallicity ratio

[Fe/H]

Distance
200.50 parsec
Light-years 653.94 ly
V-band magnitude
14.98 mag
Voyager-speed travel 11,532,280 yr

Multi-band Host Photometry — 11 bands

8.416.516.49B14.98V14.25Gaia13.30TESS12.04J11.42H11.20K11.04W111.07W210.92W38.43W4

Astrometric Data

Parallax

4.959 mas

Total Proper Motion

21.145 mas/yr

PM Right Ascension

-6.52 mas/yr

PM Declination

-20.11 mas/yr

Galactic Cartesian (pc)

x = 0.333 · y = -0.651 · z = -0.682

Equatorial (J2000)

RA 297.11032° · Dec -43.01800°

Galactic ℓ, b

356.393° · -28.117°

Ecliptic λ, β

290.985° · -21.534°

HTM-20 index

-1395801422

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