Key parameters at a glance

A radius of 2.42 Earth radii
A mass of 6.43 Earth masses
Surface gravity around 1.10 g
An orbital period of 9.151 days
Equilibrium temperature 763 K (490 °C)
Distance from Earth 355.29 light-years
Earth Similarity Index 0.336
Travel time at Voyager 1 speed 6,265,508 years

TOI-4308 b Planet Profile

Physical Specs

Radius

2.42 R⊕

Radius (Jupiter)

0.216 R♃

Mass

6.43 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.50 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.336

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

#1306of 1978

top 66.0%

This planet

2.42R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

K2-43 c 2.42 R⊕ HD 1461 b 2.42 R⊕ Kepler-717 b 2.42 R⊕

Metric	Earth	TOI-4308 b	Jupiter
Radius (R⊕)	1.00	2.42	11.21
Mass (M⊕)	1.00	6.43	317.83
Density (g/cm³)	5.51	2.50	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	55.36	0.037

Star Catalogue Identifiers

TIC

TIC 144193715

Gaia DR2

Gaia DR2 6565868036138018304

Gaia DR3

Gaia DR3 6565868036138018304

System

TOI-4308

Percentile among Sub-Neptune cohort

Radius 2.419 R⊕ · percentile 34 / cohort 1978

Mass 6.430 M⊕ · percentile 32 / cohort 1978

Orbital period 9.15 d · percentile 30 / cohort 1946

Distance 108.93 pc · percentile 21 / cohort 1975

ESI 0.336 · percentile 37 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

9.151 days

Semi-major axis

— AU

Eccentricity

—

Inclination

89.07 °

Year Length

A year here lasts approximately 9.15 Earth days (2.5% of a terrestrial year).

Transit Fingerprint

Depth

0.107 %

Duration

2.616 h

Impact parameter b

0.384

Rp / R★

0.027900

Transit midpoint (BJD)

2,458,333.4284

Photometric dip

Transit produces a flux drop of 1,074 ppm lasting ≈ 2.62 h.

Extended Orbital Architecture

Planet / star radius ratio

0.027900

Semi-major axis / stellar radius

23.606

Impact parameter (b)

0.384

Transit mid-time (BJD)

2,458,333.4284

Eq. Temperature

763K

(490 °C)

Insolation (S⊕)

55.36

Earth = 1.00

Earth Similarity (ESI)

0.336

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Mistry et al. 2023

Instrument

TESS CCD Array

Publication

2023-01

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-4184 b · Sub-Neptune

Host System: TOI-4308

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,243 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.793 R☉

Stellar Mass

0.900 M☉

Metallicity [Fe/H]

—

Distance

108.93 parsec

Light-years 355.29 ly

V-band magnitude

11.25 mag

Voyager-speed travel 6,265,508 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

9.152 mas

Total Proper Motion

72.135 mas/yr

PM Right Ascension

-72.11 mas/yr

PM Declination

-1.86 mas/yr

Galactic Cartesian (pc)

x = 0.613 · y = -0.387 · z = -0.689

Equatorial (J2000)

RA 327.75307° · Dec -43.56236°

Galactic ℓ, b

356.412° · -50.301°

Ecliptic λ, β

314.258° · -28.586°

HTM-20 index

-562285943