Key parameters at a glance

A radius of 2.43 Earth radii
A mass of 6.48 Earth masses
Surface gravity around 1.10 g
An orbital period of 4.902 days
Semi-major axis 0.0336 AU
Equilibrium temperature 412 K (139 °C)
Distance from Earth 226.24 light-years
Earth Similarity Index 0.592
Travel time at Voyager 1 speed 3,989,703 years
Almost certainly tidally locked to its host star given the close orbit

TOI-4184 b Planet Profile

Physical Specs

Radius

2.43 R⊕

Radius (Jupiter)

0.217 R♃

Mass

6.48 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.48 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.592

HZ Position Inner

Controversial No

Discovery

Year 2023

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1281of 1978

top 64.7%

This planet

2.43R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-233 b 2.43 R⊕ Kepler-55 b 2.43 R⊕ GJ 887 c 2.43 R⊕

Metric	Earth	TOI-4184 b	Jupiter
Radius (R⊕)	1.00	2.43	11.21
Mass (M⊕)	1.00	6.48	317.83
Density (g/cm³)	5.51	2.48	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	4.80	0.037

Star Catalogue Identifiers

TIC

TIC 394357918

Gaia DR2

Gaia DR2 4620574887039870720

Gaia DR3

Gaia DR3 4620574887039870720

System

TOI-4184

Percentile among Sub-Neptune cohort

Radius 2.430 R⊕ · percentile 35 / cohort 1978

Mass 6.480 M⊕ · percentile 33 / cohort 1978

Orbital period 4.90 d · percentile 12 / cohort 1946

Distance 69.36 pc · percentile 16 / cohort 1975

ESI 0.592 · percentile 81 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

4.902 days

Semi-major axis

0.0336 AU

Eccentricity

—

Inclination

89.43 °

Year Length

A year here lasts approximately 4.90 Earth days (1.3% of a terrestrial year) at a mean orbital distance of 0.0336 AU.

Transit Fingerprint

Depth

0.912 %

Duration

1.300 h

Impact parameter b

0.306

Transit midpoint (BJD)

2,459,483.6567

Photometric dip

Transit produces a flux drop of 9,115 ppm lasting ≈ 1.30 h.

Extended Orbital Architecture

Semi-major axis / stellar radius

30.790

Impact parameter (b)

0.306

Transit mid-time (BJD)

2,459,483.6567

Angular separation (arcsec)

0.48400

Eq. Temperature

412K

(139 °C)

Insolation (S⊕)

4.80

Earth = 1.00

Earth Similarity (ESI)

0.592

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Barkaoui et al. 2023

Instrument

TESS CCD Array

Publication

2023-06

Observation locale

Space

Discovery cohort

Planets confirmed in 2023 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-700 e · Rocky Terrestrial TOI-2095 c · Super-Earth TOI-715 b · Super-Earth TOI-2095 b · Super-Earth TOI-2096 c · Super-Earth TOI-1680 b · Super-Earth TOI-2096 b · Rocky Terrestrial TOI-904 c · Sub-Neptune TOI-1470 c · Sub-Neptune TOI-198 b · Super-Earth TOI-244 b · Super-Earth TOI-904 b · Sub-Neptune

Host System: TOI-4184

Spectral Class

M-type red dwarf

Effective Temperature

3,238 K — cooler than the Sun (5,778 K)

Estimated Age

6.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.235 R☉

Stellar Mass

0.211 M☉

Metallicity [Fe/H]

-0.27

Extended Stellar Properties

Surface gravity (log g)

5.010 dex

Stellar density

23.008 g/cm³

Metallicity ratio

[Fe/H]

Distance

69.36 parsec

Light-years 226.24 ly

V-band magnitude

17.12 mag

Voyager-speed travel 3,989,703 yr

Multi-band Host Photometry — 10 bands

Astrometric Data

Parallax

14.388 mas

Total Proper Motion

183.621 mas/yr

PM Right Ascension

79.05 mas/yr

PM Declination

165.74 mas/yr

Galactic Cartesian (pc)

x = 0.133 · y = 0.127 · z = -0.983

Equatorial (J2000)

RA 43.82847° · Dec -79.41470°

Galactic ℓ, b

296.218° · -36.044°

Ecliptic λ, β

295.783° · -72.264°

HTM-20 index

-225049835