Key parameters at a glance

A radius of 13.80 Earth radii
A mass of 305.12 Earth masses
Surface gravity around 1.60 g
An orbital period of 6.495 days
Semi-major axis 0.0807 AU
Distance from Earth 397.55 light-years
Earth Similarity Index 0.306
Travel time at Voyager 1 speed 7,010,821 years

HD 102956 b Planet Profile

Physical Specs

Radius

13.80 R⊕

Radius (Jupiter)

1.230 R♃

Mass

305.12 M⊕

Mass (Jupiter)

0.960 M♃

Density

0.64 g/cm³

Surface Gravity

1.60 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.306

HZ Position Unknown

Controversial No

Discovery

Year 2010

Method Radial Velocity

Facility W. M. Keck Observatory

Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#510of 1771

top 28.7%

This planet

13.80R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

GJ 179 b 13.80 R⊕ GJ 832 b 13.80 R⊕ HD 219415 b 13.80 R⊕

Metric	Earth	HD 102956 b	Jupiter
Radius (R⊕)	1.00	13.80	11.21
Mass (M⊕)	1.00	305.12	317.83
Density (g/cm³)	5.51	0.64	1.33
Surface Gravity (g)	1.00	1.60	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	305.117 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 102956

HIP

HIP 57820

TIC

TIC 137810576

Gaia DR2

Gaia DR2 845335158256083584

Gaia DR3

Gaia DR3 845335158256083584

System

HD 102956

Percentile among Gas Giant cohort

Radius 13.800 R⊕ · percentile 70 / cohort 1771

Mass 305.117 M⊕ · percentile 34 / cohort 1747

Orbital period 6.49 d · percentile 40 / cohort 1533

Distance 121.89 pc · percentile 39 / cohort 1759

ESI 0.306 · percentile 60 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

6.495 days

Semi-major axis

0.0807 AU

Eccentricity

0.037

Inclination

— °

Year Length

A year here lasts approximately 6.49 Earth days (1.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0807 AU.

Extended Orbital Architecture

Semi-major axis / stellar radius

3.953

RV semi-amplitude (K)

74.600 m/s

Long. of periastron (ω)

301.00°

Angular separation (arcsec)

0.66200

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.306

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Johnson et al. 2010

Instrument

HIRES Spectrometer

Publication

2010-10

Observation locale

Ground

Discovery cohort

Planets confirmed in 2010 at W. M. Keck Observatory (12 shown).

HD 156668 b · Super-Earth HD 1461 b · Sub-Neptune GJ 876 e · Sub-Neptune HAT-P-17 c · Gas Giant HD 97658 b · Sub-Neptune HD 163607 c · Gas Giant HD 177830 c · Neptune-like HD 218566 b · Neptune-like HD 163607 b · Gas Giant GJ 1148 b · Gas Giant HD 31253 b · Gas Giant HD 164509 b · Gas Giant

Host System: HD 102956

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

4,985 K — cooler than the Sun (5,778 K)

Estimated Age

2.30 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

4.550 R☉

Stellar Mass

1.660 M☉

Metallicity [Fe/H]

0.19

Extended Stellar Properties

Surface gravity (log g)

3.380 dex

Systemic radial velocity

-25.95 km/s

Metallicity ratio

[Fe/H]

Distance

121.89 parsec

Light-years 397.55 ly

V-band magnitude

7.86 mag

Voyager-speed travel 7,010,821 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

8.175 mas

Total Proper Motion

21.344 mas/yr

PM Right Ascension

-12.11 mas/yr

PM Declination

-17.58 mas/yr

Galactic Cartesian (pc)

x = -0.535 · y = 0.020 · z = 0.845

Equatorial (J2000)

RA 177.84370° · Dec 57.64066°

Galactic ℓ, b

137.973° · 57.699°

Ecliptic λ, β

146.461° · 50.085°

HTM-20 index

925071688

Observation Record

Photometric series

Stellar spectra

Archive notes