Key parameters at a glance

A radius of 3.48 Earth radii
A mass of 11.90 Earth masses
Surface gravity around 0.98 g
An orbital period of 13.459 days
Semi-major axis 0.0943 AU
Distance from Earth 77.90 light-years
Earth Similarity Index 0.589
Travel time at Voyager 1 speed 1,373,745 years
Almost certainly tidally locked to its host star given the close orbit

GJ 9404 b Planet Profile

Physical Specs

Radius

3.48 R⊕

Radius (Jupiter)

0.310 R♃

Mass

11.90 M⊕

Mass (Jupiter)

0.037 M♃

Density

1.55 g/cm³

Surface Gravity

0.98 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.589

HZ Position Unknown

Controversial No

Discovery

Year 2023

Method Radial Velocity

Facility Roque de los Muchachos Observatory

Telescope 3.58 m Telescopio Nazionale Galileo

Size rank in cohort

Rank by radius

#191of 1978

top 9.6%

This planet

3.48R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

K2-32 d 3.48 R⊕ Kepler-103 b 3.49 R⊕ TOI-5076 b 3.49 R⊕

Metric	Earth	GJ 9404 b	Jupiter
Radius (R⊕)	1.00	3.48	11.21
Mass (M⊕)	1.00	11.90	317.83
Density (g/cm³)	5.51	1.55	1.33
Surface Gravity (g)	1.00	0.98	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	11.900 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 60093

TIC

TIC 328860504

Gaia DR2

Gaia DR2 4010201828880793984

Gaia DR3

Gaia DR3 4010201828880793984

System

GJ 9404

Percentile among Sub-Neptune cohort

Radius 3.480 R⊕ · percentile 90 / cohort 1978

Mass 11.900 M⊕ · percentile 84 / cohort 1978

Orbital period 13.46 d · percentile 46 / cohort 1946

Distance 23.88 pc · percentile 6 / cohort 1975

ESI 0.589 · percentile 81 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

13.459 days

Semi-major axis

0.0943 AU

Eccentricity

0.490

Inclination

— °

Year Length

A year here lasts approximately 13.46 Earth days (3.7% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0943 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.589

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Baycroft et al. 2023

Instrument

HARPS-N Spectrograph

Publication

2023-08

Observation locale

Ground

Discovery cohort

Planets confirmed in 2023 at Roque de los Muchachos Observatory (7 shown).

Kepler-10 d · Sub-Neptune HD 99492 c · Neptune-like GJ 328 c · Neptune-like K2-312 c · Gas Giant Kepler-454 d · Gas Giant TOI-4010 e · Gas Giant Kepler-68 e · Gas Giant

Host System: GJ 9404

Spectral Class

M-type red dwarf

Effective Temperature

3,811 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.626 R☉

Stellar Mass

0.620 M☉

Metallicity [Fe/H]

—

Extended Stellar Properties

Surface gravity (log g)

4.629 dex

Stellar density

3.498 g/cm³

Rotation period

23.20 days

Distance

23.88 parsec

Light-years 77.90 ly

V-band magnitude

10.62 mag

Voyager-speed travel 1,373,745 yr

Multi-band Host Photometry — 13 bands

Astrometric Data

Parallax

41.840 mas

Total Proper Motion

652.520 mas/yr

PM Right Ascension

-647.72 mas/yr

PM Declination

79.01 mas/yr

Galactic Cartesian (pc)

x = -0.877 · y = -0.074 · z = 0.475

Equatorial (J2000)

RA 184.84721° · Dec 28.38271°

Galactic ℓ, b

201.047° · 82.801°

Ecliptic λ, β

172.145° · 27.756°

HTM-20 index

448053328