Confirmed Exoplanet Discovered 2025

HIP 111909 b

A gas giant orbiting the k-type orange HIP 111909, located approximately 287.3 light-years from Earth.

Key parameters at a glance

  • A radius of 13.70 Earth radii
  • A mass of 384.57 Earth masses
  • Surface gravity around 2.05 g
  • An orbital period of 487.080 days
  • Semi-major axis 1.3200 AU
  • Distance from Earth 287.27 light-years
  • Earth Similarity Index 0.324
  • Travel time at Voyager 1 speed 5,065,978 years

1 sibling around HIP 111909

HIP 111909 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
HIP 111909 b this Gas Giant 13.70 384.57 487.080 2025
HIP 111909 c Gas Giant 13.90 257.44 893.630 2025

HIP 111909 b Planet Profile

Physical Specs

Radius
13.70 R⊕
Radius (Jupiter)
1.220 R♃
Mass
384.57 M⊕
Mass (Jupiter)
1.210 M♃
Density
0.82 g/cm³
Surface Gravity
2.05 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.324
HZ Position Unknown
Controversial No

Discovery

Year 2025
Method Radial Velocity
Facility Multiple Observatories
Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#554of 1771

top 31.2%

This planet

13.70R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth HIP 111909 b Jupiter
Radius (R⊕)1.0013.7011.21
Mass (M⊕)1.00384.57317.83
Density (g/cm³)5.510.821.33
Surface Gravity (g)1.002.052.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Minimum mass (M sin i) 384.572 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 111909

TIC

TIC 161173454

Gaia DR2

Gaia DR2 6517272336609082880

Gaia DR3

Gaia DR3 6517272336609082880

System

HIP 111909

Percentile among Gas Giant cohort

Radius 13.700 R⊕ · percentile 66 / cohort 1771
Mass 384.572 M⊕ · percentile 41 / cohort 1747
Orbital period 487.08 d · percentile 67 / cohort 1533
Distance 88.08 pc · percentile 32 / cohort 1759
ESI 0.324 · percentile 64 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
487.080 days
Semi-major axis
1.3200 AU
Eccentricity
Inclination
°

Year Length

A year here lasts about 1.33 Earth years at a mean orbital distance of 1.3200 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.324

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Jenkins et al. 2025

Instrument

Multiple Instruments

Publication

2025-09

Observation locale

Ground

Host System: HIP 111909

Spectral Class

K-type orange

Effective Temperature

4,891 K — cooler than the Sun (5,778 K)

Estimated Age

4.30 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

4.530 R☉

Stellar Mass

1.280 M☉

Metallicity [Fe/H]

-0.01

Extended Stellar Properties

Surface gravity (log g)

3.090 dex

Rotational v·sin i

3.13 km/s

Metallicity ratio

[Fe/H]

Distance
88.08 parsec
Light-years 287.27 ly
V-band magnitude
7.37 mag
Voyager-speed travel 5,065,978 yr

Multi-band Host Photometry — 11 bands

4.88.48.41B7.37V7.10Gaia6.50TESS5.65J5.27H5.02K4.94W14.84W25.02W34.94W4

Astrometric Data

Parallax

11.325 mas

Total Proper Motion

100.298 mas/yr

PM Right Ascension

77.65 mas/yr

PM Declination

-63.49 mas/yr

Galactic Cartesian (pc)

x = 0.609 · y = -0.221 · z = -0.762

Equatorial (J2000)

RA 340.03044° · Dec -49.59854°

Galactic ℓ, b

342.225° · -56.300°

Ecliptic λ, β

320.282° · -37.635°

HTM-20 index

968676626

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