Confirmed Exoplanet Discovered 2025

HD 87816 b

A gas giant orbiting the k-type orange HD 87816, located approximately 434.5 light-years from Earth.

Key parameters at a glance

  • A radius of 12.70 Earth radii
  • A mass of 2,142.16 Earth masses
  • Surface gravity around 13.28 g
  • An orbital period of 484.170 days
  • Semi-major axis 1.6180 AU
  • Distance from Earth 434.55 light-years
  • Earth Similarity Index 0.437
  • Travel time at Voyager 1 speed 7,663,243 years

1 sibling around HD 87816

HD 87816 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
HD 87816 b this Gas Giant 12.70 2,142.16 484.170 2025
HD 87816 c Gas Giant 12.40 3,877.51 7,596.000 2025

HD 87816 b Planet Profile

Physical Specs

Radius
12.70 R⊕
Radius (Jupiter)
1.130 R♃
Mass
2,142.16 M⊕
Mass (Jupiter)
6.740 M♃
Density
5.75 g/cm³
Surface Gravity
13.28 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.437
HZ Position Unknown
Controversial No

Discovery

Year 2025
Method Radial Velocity
Facility La Silla Observatory
Telescope 1.2 m Leonhard Euler Telescope

Size rank in cohort

Rank by radius

#1130of 1771

top 63.7%

This planet

12.70R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth HD 87816 b Jupiter
Radius (R⊕)1.0012.7011.21
Mass (M⊕)1.002,142.16317.83
Density (g/cm³)5.515.751.33
Surface Gravity (g)1.0013.282.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Minimum mass (M sin i) 2,142.163 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 87816

HIP

HIP 49477

TIC

TIC 138998040

Gaia DR2

Gaia DR2 5404921677215434112

Gaia DR3

Gaia DR3 5404921677218538496

System

HD 87816

Percentile among Gas Giant cohort

Radius 12.700 R⊕ · percentile 34 / cohort 1771
Mass 2,142.163 M⊕ · percentile 81 / cohort 1747
Orbital period 484.17 d · percentile 67 / cohort 1533
Distance 133.23 pc · percentile 41 / cohort 1759
ESI 0.437 · percentile 96 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
484.170 days
Semi-major axis
1.6180 AU
Eccentricity
0.780
Inclination
°

Year Length

A year here lasts about 1.33 Earth years on a highly eccentric trajectory at a mean orbital distance of 1.6180 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.437

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Fontanet et al. 2025

Instrument

CORALIE Spectrograph

Publication

2025-05

Observation locale

Ground

Host System: HD 87816

Spectral Class

K-type orange

Effective Temperature

4,989 K — cooler than the Sun (5,778 K)

Estimated Age

Stellar Radius

9.000 R☉

Stellar Mass

2.410 M☉

Metallicity [Fe/H]

0.14

Distance
133.23 parsec
Light-years 434.55 ly
V-band magnitude
6.50 mag
Voyager-speed travel 7,663,243 yr

Multi-band Host Photometry — 11 bands

3.97.57.50B6.50V6.24Gaia5.66TESS4.87J4.49H4.28K4.14W13.88W24.21W34.15W4

Astrometric Data

Parallax

7.477 mas

Total Proper Motion

58.051 mas/yr

PM Right Ascension

-55.72 mas/yr

PM Declination

16.29 mas/yr

Galactic Cartesian (pc)

x = -0.539 · y = 0.292 · z = -0.790

Equatorial (J2000)

RA 151.52965° · Dec -52.18787°

Galactic ℓ, b

279.018° · 2.836°

Ecliptic λ, β

184.887° · -57.255°

HTM-20 index

-1284584493

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