Confirmed Exoplanet Discovered 2026

KOINTREAU-4 b

A gas giant orbiting the m-type red dwarf 2MASS J16262785-2625152, located approximately 474.3 light-years from Earth.

Key parameters at a glance

  • A radius of 12.20 Earth radii
  • A mass of 4,862.77 Earth masses
  • Surface gravity around 32.67 g
  • Semi-major axis 182.0000 AU
  • Distance from Earth 474.34 light-years
  • Earth Similarity Index 0.325
  • Travel time at Voyager 1 speed 8,365,016 years

KOINTREAU-4 b Planet Profile

Physical Specs

Radius
12.20 R⊕
Radius (Jupiter)
1.090 R♃
Mass
4,862.77 M⊕
Mass (Jupiter)
15.300 M♃
Density
14.70 g/cm³
Surface Gravity
32.67 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.325
HZ Position Unknown
Controversial No

Discovery

Year 2026
Method Imaging
Facility W. M. Keck Observatory
Telescope 10 m Keck II 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 KOINTREAU-4 b Jupiter
Radius (R⊕)1.0012.2011.21
Mass (M⊕)1.004,862.77317.83
Density (g/cm³)5.5114.701.33
Surface Gravity (g)1.0032.672.53
Insolation (S⊕)1.00—0.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 4,862.775 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 175594111

Gaia DR2

Gaia DR2 6045818685674325760

Gaia DR3

Gaia DR3 6045818685674325760

System

2MASS J16262785-2625152

Percentile among Gas Giant cohort

Radius 12.200 R⊕ · percentile 19 / cohort 1771
Mass 4,862.775 M⊕ · percentile 94 / cohort 1747
Distance 145.43 pc · percentile 43 / cohort 1759
ESI 0.325 · percentile 64 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
— days
Semi-major axis
182.0000 AU
Eccentricity
—
Inclination
— °

Year Length

Orbital period for this planet has not yet been measured.

Eq. Temperature

—

 

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.325

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Walker et al. 2026

Instrument

NIRC2 Camera

Publication

2026-03

Observation locale

Ground

Discovery cohort

Planets confirmed in 2026 at W. M. Keck Observatory (2 shown).

KOINTREAU-3 b · Gas Giant KOINTREAU-1 b · Gas Giant

Host System: 2MASS J16262785-2625152

Spectral Class

M-type red dwarf

Effective Temperature

3,252 K — cooler than the Sun (5,778 K)

Estimated Age

0.01 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

—

Stellar Mass

—

Metallicity [Fe/H]

—

Distance
145.43 parsec
Light-years 474.34 ly
V-band magnitude
15.90 mag
Voyager-speed travel 8,365,016 yr

Multi-band Host Photometry — 12 bands

8.517.017.03B15.90V14.10Gaia13.39Kepler12.90TESS10.84J10.18H9.85K9.65W19.43W29.32W38.53W4

Astrometric Data

Parallax

6.849 mas

Total Proper Motion

28.170 mas/yr

PM Right Ascension

-5.62 mas/yr

PM Declination

-27.60 mas/yr

Galactic Cartesian (pc)

x = -0.355 · y = -0.822 · z = -0.445

Equatorial (J2000)

RA 246.61605° · Dec -26.42100°

Galactic ℓ, b

351.502° · 15.564°

Ecliptic λ, β

249.104° · -4.662°

HTM-20 index

-306054644

Similar Worlds

ROXs 12 b

Gas Giant · M-type red dwarf

Radius 12.20 R⊕ · 445.7 ly

HD 112300 b

Gas Giant · M-type red dwarf

Radius 12.20 R⊕ · 202.5 ly

HD 220074 b

Gas Giant · M-type red dwarf

Radius 12.20 R⊕ · 1,058.5 ly

FU Tau b

Gas Giant · M-type red dwarf

Radius 12.20 R⊕ · 435.4 ly

2MASS J03590986+2009361 b

Gas Giant · M-type red dwarf

Radius 12.20 R⊕ · 383.0 ly

USco1621 b

Gas Giant · M-type red dwarf

Radius 12.20 R⊕ · 449.8 ly

Explore Related Categories

Gas Giant Planets Imaging Discoveries W. M. Keck Observatory Mission M-type red dwarf Hosts