Key parameters at a glance

A radius of 13.60 Earth radii
A mass of 425.89 Earth masses
Surface gravity around 2.30 g
An orbital period of 4,168.690 days
Semi-major axis 4.0100 AU
Distance from Earth 3,392.02 light-years
Earth Similarity Index 0.333
Travel time at Voyager 1 speed 59,818,312 years

AT2021ueyL b Planet Profile

Physical Specs

Radius

13.60 R⊕

Radius (Jupiter)

1.220 R♃

Mass

425.89 M⊕

Mass (Jupiter)

1.340 M♃

Density

0.93 g/cm³

Surface Gravity

2.30 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.333

HZ Position Unknown

Controversial No

Discovery

Year 2025

Method Microlensing

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#609of 1771

top 34.3%

This planet

13.60R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 19994 b 13.60 R⊕ HD 205739 b 13.60 R⊕ HD 79498 b 13.60 R⊕

Metric	Earth	AT2021ueyL b	Jupiter
Radius (R⊕)	1.00	13.60	11.21
Mass (M⊕)	1.00	425.89	317.83
Density (g/cm³)	5.51	0.93	1.33
Surface Gravity (g)	1.00	2.30	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	425.890 M⊕	Direct mass measurement (not derived).

Percentile among Gas Giant cohort

Radius 13.600 R⊕ · percentile 63 / cohort 1771

Mass 425.890 M⊕ · percentile 44 / cohort 1747

Orbital period 4,168.69 d · percentile 91 / cohort 1533

Distance 1,040.00 pc · percentile 87 / cohort 1759

ESI 0.333 · percentile 66 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

4,168.690 days

Semi-major axis

4.0100 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts about 11.41 Earth years at a mean orbital distance of 4.0100 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.333

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Ban et al. 2025

Instrument

Multiple Instruments

Publication

2025-03

Observation locale

Multiple Locales

Discovery cohort

Planets confirmed in 2025 at Multiple Observatories (12 shown).

Gl 725 A b · Super-Earth HD 20794 f · Sub-Neptune GJ 3998 d · Sub-Neptune GJ 251 c · Super-Earth HD 86728 b · Sub-Neptune TOI-2015 c · Sub-Neptune Kepler-139 f · Neptune-like HD 73344 d · Gas Giant TOI-1472 c · Sub-Neptune TOI-6695 c · Gas Giant HIP 111909 b · Gas Giant TOI-6041 c · Gas Giant

Host System: AT2021ueyL

Spectral Class

M-type red dwarf

Effective Temperature

3,680 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

—

Stellar Mass

0.490 M☉

Metallicity [Fe/H]

—

Distance

1,040.00 parsec

Light-years 3,392.02 ly

V-band magnitude

— mag

Voyager-speed travel 59,818,312 yr

Similar Worlds

GJ 317 c

Gas Giant · M-type red dwarf

Radius 13.60 R⊕ · 49.6 ly

GJ 2126 b

Gas Giant · M-type red dwarf

Radius 13.60 R⊕ · 124.4 ly

VHS J125601.92-125723.9 b

Gas Giant · M-type red dwarf

Radius 13.67 R⊕ · 41.4 ly

TOI-4201 b

Gas Giant · M-type red dwarf

Radius 13.67 R⊕ · 616.5 ly

GJ 179 b

Gas Giant · M-type red dwarf

Radius 13.80 R⊕ · 40.3 ly

GJ 832 b

Gas Giant · M-type red dwarf

Radius 13.80 R⊕ · 16.2 ly

Explore Related Categories

Gas Giant Planets Microlensing Discoveries Multiple Observatories Mission M-type red dwarf Hosts