Key parameters at a glance

A radius of 4.33 Earth radii
A mass of 17.30 Earth masses
Surface gravity around 0.92 g
Distance from Earth 23,515.85 light-years
Earth Similarity Index 0.519
Travel time at Voyager 1 speed 414,701,949 years

1 sibling around KMT-2024-BLG-0404L

KMT-2024-BLG-0404L c shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
KMT-2024-BLG-0404L c this	Neptune-like	4.33	17.30	—	—	2025
KMT-2024-BLG-0404L b	Gas Giant	11.90	8,657.65	—	—	2025

KMT-2024-BLG-0404L c Planet Profile

Physical Specs

Radius

4.33 R⊕

Radius (Jupiter)

0.386 R♃

Mass

17.30 M⊕

Mass (Jupiter)

0.054 M♃

Density

1.17 g/cm³

Surface Gravity

0.92 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.519

HZ Position Unknown

Controversial No

Discovery

Year 2025

Method Microlensing

Facility KMTNet

Telescope 1.6 m wide-field telescope

Size rank in cohort

Rank by radius

#487of 574

top 84.7%

This planet

4.33R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

GJ 687 b 4.32 R⊕ Kepler-145 c 4.32 R⊕ KOI-94 c 4.32 R⊕

Metric	Earth	KMT-2024-BLG-0404L c	Jupiter
Radius (R⊕)	1.00	4.33	11.21
Mass (M⊕)	1.00	17.30	317.83
Density (g/cm³)	5.51	1.17	1.33
Surface Gravity (g)	1.00	0.92	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	17.300 M⊕	Direct mass measurement (not derived).

Percentile among Neptune-like cohort

Radius 4.330 R⊕ · percentile 15 / cohort 574

Mass 17.300 M⊕ · percentile 19 / cohort 574

Distance 7,210.00 pc · percentile 98 / cohort 572

ESI 0.519 · percentile 94 / cohort 574

Orbit & Habitability

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.519

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Han et al. 2025

Instrument

18k Mosaic CCD camera

Publication

2025-08

Observation locale

Ground

Discovery cohort

Planets confirmed in 2025 at KMTNet (12 shown).

KMT-2024-BLG-2059L b · Sub-Neptune KMT-2024-BLG-2242L b · Sub-Neptune KMT-2023-BLG-1896L b · Neptune-like KMT-2023-BLG-0830L b · Neptune-like KMT-2024-BLG-1281L b · Neptune-like KMT-2021-BLG-0736L b · Neptune-like KMT-2023-BLG-0949L b · Gas Giant KMT-2023-BLG-0548L b · Gas Giant KMT-2017-BLG-2197L b · Gas Giant KMT-2024-BLG-1209L b · Gas Giant KMT-2022-BLG-1790L b · Gas Giant KMT-2019-BLG-0578L b · Gas Giant

Host System: KMT-2024-BLG-0404L

Spectral Class

M-type red dwarf

Effective Temperature

—

Estimated Age

—

Stellar Radius

—

Stellar Mass

0.090 M☉

Metallicity [Fe/H]

—

Distance

7,210.00 parsec

Light-years 23,515.85 ly

V-band magnitude

— mag

Voyager-speed travel 414,701,949 yr