Key parameters at a glance

A radius of 12.60 Earth radii
A mass of 2,685.65 Earth masses
Surface gravity around 16.92 g
An orbital period of 3,700.000 days
Semi-major axis 5.0000 AU
Equilibrium temperature 145 K (-128 °C)
Distance from Earth 285.86 light-years
Earth Similarity Index 0.291
Travel time at Voyager 1 speed 5,041,056 years

HD 115954 b Planet Profile

Physical Specs

Radius

12.60 R⊕

Radius (Jupiter)

1.120 R♃

Mass

2,685.65 M⊕

Mass (Jupiter)

8.450 M♃

Density

7.38 g/cm³

Surface Gravity

16.92 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.291

HZ Position Outer

Controversial No

Discovery

Year 2021

Method Radial Velocity

Facility Haute-Provence Observatory

Telescope 1.93 m Telescope

Size rank in cohort

Rank by radius

#1179of 1771

top 66.5%

This planet

12.60R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Kepler-419 c 12.60 R⊕ 2MASS J04414489+2301513 b 12.60 R⊕ HD 47536 b 12.60 R⊕

Metric	Earth	HD 115954 b	Jupiter
Radius (R⊕)	1.00	12.60	11.21
Mass (M⊕)	1.00	2,685.65	317.83
Density (g/cm³)	5.51	7.38	1.33
Surface Gravity (g)	1.00	16.92	2.53
Insolation (S⊕)	1.00	0.06	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2,685.650 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	2,634.797 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 115954

HIP

HIP 65042

TIC

TIC 180655149

Gaia DR2

Gaia DR2 1476407794119745536

Gaia DR3

Gaia DR3 1476407794120339328

System

HD 115954

Percentile among Gas Giant cohort

Radius 12.600 R⊕ · percentile 31 / cohort 1771

Mass 2,685.650 M⊕ · percentile 85 / cohort 1747

Orbital period 3,700.00 d · percentile 90 / cohort 1533

Distance 87.64 pc · percentile 32 / cohort 1759

ESI 0.291 · percentile 56 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

3,700.000 days

Semi-major axis

5.0000 AU

Eccentricity

0.487

Inclination

79.00 °

Year Length

A year here lasts about 10.13 Earth years on a highly eccentric trajectory at a mean orbital distance of 5.0000 AU.

Extended Orbital Architecture

Semi-major axis / stellar radius

903.000

RV semi-amplitude (K)

110.700 m/s

Long. of periastron (ω)

185.60°

Angular separation (arcsec)

57.00000

Eq. Temperature

145K

(-128 °C)

Insolation (S⊕)

0.06

Earth = 1.00

Earth Similarity (ESI)

0.291

0 = alien, 1 = Earth-identical

Beyond the outer HZ boundary (too cold) — any water would exist as deep ice.

Detection Signatures

Radial velocity

Stellar wobble has been measured spectroscopically.

Astrometry

Positional wobble of the host star was measured.

Discovery Paper

Primary reference

Demangeon et al. 2021

Instrument

SOPHIE Spectrograph

Publication

2021-09

Observation locale

Ground

Discovery cohort

Planets confirmed in 2021 at Haute-Provence Observatory (11 shown).

HD 27969 b · Gas Giant HD 109286 b · Gas Giant HD 211403 b · Gas Giant HD 80869 b · Gas Giant BD+63 1405 b · Gas Giant HD 331093 b · Gas Giant BD+45 564 b · Gas Giant HD 95544 b · Gas Giant HD 124330 b · Gas Giant HD 155193 b · Gas Giant BD+55 362 b · Gas Giant

Host System: HD 115954

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,957 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.213 R☉

Stellar Mass

1.180 M☉

Metallicity [Fe/H]

0.34

Extended Stellar Properties

Surface gravity (log g)

4.150 dex

Stellar density

0.302 g/cm³

Rotational v·sin i

5.30 km/s

Metallicity ratio

[Fe/H]

Distance

87.64 parsec

Light-years 285.86 ly

V-band magnitude

8.34 mag

Voyager-speed travel 5,041,056 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

11.381 mas

Total Proper Motion

77.793 mas/yr

PM Right Ascension

-74.76 mas/yr

PM Declination

21.52 mas/yr

Galactic Cartesian (pc)

x = -0.737 · y = -0.268 · z = 0.621

Equatorial (J2000)

RA 199.98537° · Dec 38.36914°

Galactic ℓ, b

96.737° · 77.272°

Ecliptic λ, β

179.914° · 42.539°

HTM-20 index

1751443685