Confirmed Exoplanet Discovered 2025

TOI-3523 A b

A gas giant orbiting the f-type yellow-white TOI-3523 A, located approximately 2,104.7 light-years from Earth.

Key parameters at a glance

  • A radius of 15.97 Earth radii
  • A mass of 435.42 Earth masses
  • Surface gravity around 1.71 g
  • An orbital period of 2.305 days
  • Semi-major axis 0.0356 AU
  • Equilibrium temperature 1,984 K (1711 °C)
  • Distance from Earth 2,104.67 light-years
  • Earth Similarity Index 0.057
  • Travel time at Voyager 1 speed 37,115,767 years

TOI-3523 A b Planet Profile

Physical Specs

Radius
15.97 R⊕
Radius (Jupiter)
1.425 R♃
Mass
435.42 M⊕
Mass (Jupiter)
1.370 M♃
Density
0.59 g/cm³
Surface Gravity
1.71 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.057
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

#165of 1771

top 9.3%

This planet

15.97R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth TOI-3523 A b Jupiter
Radius (R⊕)1.0015.9711.21
Mass (M⊕)1.00435.42317.83
Density (g/cm³)5.510.591.33
Surface Gravity (g)1.001.712.53
Insolation (S⊕)1.002,590.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 435.425 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 417047499

Gaia DR2

Gaia DR2 2080811118319262080

Gaia DR3

Gaia DR3 2080811118319262080

System

TOI-3523

Percentile among Gas Giant cohort

Radius 15.973 R⊕ · percentile 91 / cohort 1771
Mass 435.425 M⊕ · percentile 45 / cohort 1747
Orbital period 2.30 d · percentile 10 / cohort 1533
Distance 645.29 pc · percentile 80 / cohort 1759
ESI 0.057 · percentile 7 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
2.305 days
Semi-major axis
0.0356 AU
Eccentricity
0.047
Inclination
88.30 °

Year Length

A year here lasts approximately 2.30 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0356 AU.

Transit Fingerprint

Depth

1.022 %

Duration

3.650 h

Impact parameter b

0.160

Transit midpoint (BJD)

2,460,417.4556

Photometric dip

Transit produces a flux drop of 10,220 ppm lasting ≈ 3.65 h.

Extended Orbital Architecture

Semi-major axis / stellar radius

5.298

Impact parameter (b)

0.160

RV semi-amplitude (K)

194.000 m/s

Transit mid-time (BJD)

2,460,417.4556

Angular separation (arcsec)

0.05520

Eq. Temperature

1,984K

(1711 °C)

Insolation (S⊕)

2,590.00

Earth = 1.00

Earth Similarity (ESI)

0.057

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

Yee et al. 2025

Instrument

TESS CCD Array

Publication

2025-07

Observation locale

Space

Host System: TOI-3523 A

Spectral Class

F-type yellow-white

Effective Temperature

6,450 K — hotter than the Sun (5,778 K)

Estimated Age

4.30 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.448 R☉

Stellar Mass

1.131 M☉

Metallicity [Fe/H]

-0.37

Extended Stellar Properties

Surface gravity (log g)

4.171 dex

Stellar density

0.529 g/cm³

Metallicity ratio

[Fe/H]

Distance
645.29 parsec
Light-years 2,104.67 ly
V-band magnitude
12.56 mag
Voyager-speed travel 37,115,767 yr

Multi-band Host Photometry — 11 bands

8.912.912.95B12.56V12.49Gaia12.10TESS11.45J11.23H11.15K11.03W111.08W210.50W38.92W4

Astrometric Data

Parallax

1.524 mas

Total Proper Motion

11.611 mas/yr

PM Right Ascension

0.66 mas/yr

PM Declination

-11.59 mas/yr

Galactic Cartesian (pc)

x = 0.413 · y = -0.605 · z = 0.681

Equatorial (J2000)

RA 304.28346° · Dec 42.90653°

Galactic ℓ, b

79.803° · 4.147°

Ecliptic λ, β

325.412° · 59.924°

HTM-20 index

357234410

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