Key parameters at a glance

A radius of 10.30 Earth radii
A mass of 58.70 Earth masses
Surface gravity around 0.55 g
An orbital period of 10.591 days
Semi-major axis 0.0980 AU
Equilibrium temperature 947 K (674 °C)
Distance from Earth 426.79 light-years
Earth Similarity Index 0.133
Travel time at Voyager 1 speed 7,526,467 years

1 sibling around TOI-5398

TOI-5398 b 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
TOI-5398 c	Sub-Neptune	3.52	11.80	4.773	1,242	2023
TOI-5398 b this	Gas Giant	10.30	58.70	10.591	947	2022

TOI-5398 b Planet Profile

Physical Specs

Radius

10.30 R⊕

Radius (Jupiter)

0.919 R♃

Mass

58.70 M⊕

Mass (Jupiter)

0.185 M♃

Density

0.29 g/cm³

Surface Gravity

0.55 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.133

HZ Position Inner

Controversial No

Discovery

Year 2022

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1743of 1771

top 98.4%

This planet

10.30R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

TOI-1386 c 10.30 R⊕ OGLE-2017-BLG-0364L b 10.30 R⊕ TOI-1338 c 10.30 R⊕

Metric	Earth	TOI-5398 b	Jupiter
Radius (R⊕)	1.00	10.30	11.21
Mass (M⊕)	1.00	58.70	317.83
Density (g/cm³)	5.51	0.29	1.33
Surface Gravity (g)	1.00	0.55	2.53
Insolation (S⊕)	1.00	118.41	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	58.700 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 8260536

Gaia DR2

Gaia DR2 750888548244441344

Gaia DR3

Gaia DR3 750888548244441344

System

TOI-5398

Percentile among Gas Giant cohort

Radius 10.300 R⊕ · percentile 1 / cohort 1771

Mass 58.700 M⊕ · percentile 1 / cohort 1747

Orbital period 10.59 d · percentile 45 / cohort 1533

Distance 130.86 pc · percentile 41 / cohort 1759

ESI 0.133 · percentile 34 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

10.591 days

Semi-major axis

0.0980 AU

Eccentricity

0.130

Inclination

89.21 °

Year Length

A year here lasts approximately 10.59 Earth days (2.9% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0980 AU.

Transit Fingerprint

Depth

1.029 %

Duration

4.258 h

Impact parameter b

0.272

Rp / R★

0.089900

Transit midpoint (BJD)

2,459,616.4923

Photometric dip

Transit produces a flux drop of 10,290 ppm lasting ≈ 4.26 h.

Extended Orbital Architecture

Planet / star radius ratio

0.089900

Semi-major axis / stellar radius

20.000

Impact parameter (b)

0.272

RV semi-amplitude (K)

15.700 m/s

Transit mid-time (BJD)

2,459,616.4923

Long. of periastron (ω)

92.00°

Angular separation (arcsec)

0.74900

Eq. Temperature

947K

(674 °C)

Insolation (S⊕)

118.41

Earth = 1.00

Earth Similarity (ESI)

0.133

0 = alien, 1 = Earth-identical

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

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Mantovan et al. 2022

Instrument

TESS CCD Array

Publication

2022-11

Observation locale

Space

Discovery cohort

Planets confirmed in 2022 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-1452 b · Super-Earth TOI-712 d · Sub-Neptune TOI-1468 c · Sub-Neptune TOI-2136 b · Sub-Neptune LTT 1445 A c · Rocky Terrestrial TOI-712 c · Sub-Neptune LP 890-9 b · Super-Earth TOI-2081 b · Sub-Neptune GJ 3929 b · Rocky Terrestrial HD 260655 c · Super-Earth HD 73583 c · Sub-Neptune TOI-1759 b · Sub-Neptune

Host System: TOI-5398

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

6,000 K — hotter than the Sun (5,778 K)

Estimated Age

0.65 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.051 R☉

Stellar Mass

1.146 M☉

Metallicity [Fe/H]

0.09

Extended Stellar Properties

Surface gravity (log g)

4.440 dex

Stellar density

1.343 g/cm³

Systemic radial velocity

-9.95 km/s

Rotational v·sin i

7.50 km/s

Rotation period

7.34 days

Activity index (log R'HK)

-4.430

Metallicity ratio

[Fe/H]

Distance

130.86 parsec

Light-years 426.79 ly

V-band magnitude

10.06 mag

Voyager-speed travel 7,526,467 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

7.613 mas

Total Proper Motion

6.873 mas/yr

PM Right Ascension

1.33 mas/yr

PM Declination

6.74 mas/yr

Galactic Cartesian (pc)

x = -0.766 · y = 0.251 · z = 0.592

Equatorial (J2000)

RA 161.87956° · Dec 36.32943°

Galactic ℓ, b

185.821° · 62.233°

Ecliptic λ, β

148.696° · 26.351°

HTM-20 index

638923493