Confirmed Exoplanet Discovered 2025

TIC 434398831 b

A sub-neptune orbiting the g-type yellow (sun-like) TIC 434398831, located approximately 707.8 light-years from Earth.

Key parameters at a glance

  • A radius of 3.51 Earth radii
  • A mass of 12.10 Earth masses
  • Surface gravity around 0.98 g
  • An orbital period of 3.686 days
  • Semi-major axis 0.0464 AU
  • Equilibrium temperature 1,250 K (977 °C)
  • Distance from Earth 707.79 light-years
  • Earth Similarity Index 0.170
  • Travel time at Voyager 1 speed 12,481,953 years

1 sibling around TIC 434398831

TIC 434398831 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
TIC 434398831 b this Sub-Neptune 3.51 12.10 3.686 1,250 2025
TIC 434398831 c Neptune-like 5.63 27.00 6.210 1,050 2025

TIC 434398831 b Planet Profile

Physical Specs

Radius
3.51 R⊕
Radius (Jupiter)
0.313 R♃
Mass
12.10 M⊕
Mass (Jupiter)
0.038 M♃
Density
1.54 g/cm³
Surface Gravity
0.98 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.170
HZ Position Unknown
Controversial No

Discovery

Year 2025
Method Transit
Facility Transiting Exoplanet Survey Satellite (TESS)
Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#176of 1978

top 8.8%

This planet

3.51R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth TIC 434398831 b Jupiter
Radius (R⊕)1.003.5111.21
Mass (M⊕)1.0012.10317.83
Density (g/cm³)5.511.541.33
Surface Gravity (g)1.000.982.53
Insolation (S⊕)1.000.037

Star Catalogue Identifiers

TIC

TIC 434398831

Gaia DR2

Gaia DR2 3369841304767966976

Gaia DR3

Gaia DR3 3369841304767966976

System

TIC 434398831

Percentile among Sub-Neptune cohort

Radius 3.510 R⊕ · percentile 91 / cohort 1978
Mass 12.100 M⊕ · percentile 84 / cohort 1978
Orbital period 3.69 d · percentile 7 / cohort 1946
Distance 217.01 pc · percentile 30 / cohort 1975
ESI 0.170 · percentile 4 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
3.686 days
Semi-major axis
0.0464 AU
Eccentricity
0.040
Inclination
88.20 °

Year Length

A year here lasts approximately 3.69 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0464 AU.

Transit Fingerprint

Duration

2.760 h

Rp / R★

0.035300

Transit midpoint (BJD)

2,458,468.6350

Extended Orbital Architecture

Planet / star radius ratio

0.035300

Semi-major axis / stellar radius

10.100

Transit mid-time (BJD)

2,458,468.6350

Long. of periastron (ω)

-61.00°

Angular separation (arcsec)

0.21400

Eq. Temperature

1,250K

(977 °C)

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.170

0 = alien, 1 = Earth-identical

Insufficient insolation data — the dayside is scorched.

Discovery Paper

Primary reference

Vach et al. 2025

Instrument

TESS CCD Array

Publication

2025-06

Observation locale

Space

Host System: TIC 434398831

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,638 K — cooler than the Sun (5,778 K)

Estimated Age

0.06 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.909 R☉

Stellar Mass

0.992 M☉

Metallicity [Fe/H]

-0.08

Extended Stellar Properties

Surface gravity (log g)

4.420 dex

Stellar density

1.797 g/cm³

Rotational v·sin i

32.16 km/s

Rotation period

1.75 days

Metallicity ratio

[m/H]

Distance
217.01 parsec
Light-years 707.79 ly
V-band magnitude
11.68 mag
Voyager-speed travel 12,481,953 yr

Multi-band Host Photometry — 11 bands

8.412.512.48B11.68V11.79Gaia11.31TESS10.59J10.24H10.14K9.94W110.05W29.99W38.44W4

Astrometric Data

Parallax

4.580 mas

Total Proper Motion

17.333 mas/yr

PM Right Ascension

5.53 mas/yr

PM Declination

-16.43 mas/yr

Galactic Cartesian (pc)

x = -0.066 · y = 0.959 · z = 0.276

Equatorial (J2000)

RA 93.95926° · Dec 16.02385°

Galactic ℓ, b

194.663° · -0.371°

Ecliptic λ, β

93.833° · -7.363°

HTM-20 index

-911112918

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