Confirmed Exoplanet Discovered 2025

CWISEP J193518.59-154620.3 b

A gas giant orbiting the y-type cold brown dwarf CWISEP J193518.59-154620.3, located approximately 47.1 light-years from Earth.

Key parameters at a glance

  • A radius of 12.20 Earth radii
  • A mass of 4,926.34 Earth masses
  • Surface gravity around 33.10 g
  • Semi-major axis 2.4800 AU
  • Equilibrium temperature 390 K (117 °C)
  • Distance from Earth 47.06 light-years
  • Earth Similarity Index 0.342
  • Travel time at Voyager 1 speed 829,979 years

CWISEP J193518.59-154620.3 b Planet Profile

Physical Specs

Radius
12.20 R⊕
Radius (Jupiter)
1.090 R♃
Mass
4,926.34 M⊕
Mass (Jupiter)
15.500 M♃
Density
14.90 g/cm³
Surface Gravity
33.10 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.342
HZ Position Unknown
Controversial No

Discovery

Year 2025
Method Imaging
Facility James Webb Space Telescope (JWST)
Telescope 6.5 m James Webb Space Telescope

Size rank in cohort

Rank by radius

#1410of 1771

top 79.6%

This planet

12.20R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

FU Tau b 12.20 R⊕ HD 168443 c 12.20 R⊕ HIP 5158 c 12.20 R⊕
Metric Earth CWISEP J193518.59-154620.3 b Jupiter
Radius (R⊕)1.0012.2011.21
Mass (M⊕)1.004,926.34317.83
Density (g/cm³)5.5114.901.33
Surface Gravity (g)1.0033.102.53
Insolation (S⊕)1.00—0.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 4,926.340 M⊕ Direct mass measurement (not derived).

Percentile among Gas Giant cohort

Radius 12.200 R⊕ · percentile 19 / cohort 1771
Mass 4,926.340 M⊕ · percentile 94 / cohort 1747
Distance 14.43 pc · percentile 2 / cohort 1759
ESI 0.342 · percentile 69 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
— days
Semi-major axis
2.4800 AU
Eccentricity
—
Inclination
— °

Year Length

Orbital period for this planet has not yet been measured.

Eq. Temperature

390K

(117 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.342

0 = alien, 1 = Earth-identical

Insufficient insolation data — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

De Furio et al. 2025

Instrument

Mid-Infrared Instrument (MIRI)

Publication

2025-09

Observation locale

Space

Host System: CWISEP J193518.59-154620.3

Spectral Class

Y-type cold brown dwarf

Effective Temperature

—

Estimated Age

5.50 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

—

Stellar Mass

0.024 M☉

Metallicity [Fe/H]

—

Distance
14.43 parsec
Light-years 47.06 ly
V-band magnitude
— mag
Voyager-speed travel 829,979 yr

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