Key parameters at a glance

A radius of 12.90 Earth radii
A mass of 1,357.13 Earth masses
Surface gravity around 8.16 g
An orbital period of 1,827.000 days
Semi-major axis 3.1800 AU
Distance from Earth 254.30 light-years
Earth Similarity Index 0.422
Travel time at Voyager 1 speed 4,484,608 years

HD 55696 b Planet Profile

Physical Specs

Radius

12.90 R⊕

Radius (Jupiter)

1.160 R♃

Mass

1,357.13 M⊕

Mass (Jupiter)

4.270 M♃

Density

3.47 g/cm³

Surface Gravity

8.16 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.422

HZ Position Unknown

Controversial No

Discovery

Year 2018

Method Radial Velocity

Facility W. M. Keck Observatory

Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#1011of 1771

top 57.0%

This planet

12.90R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 24040 b 12.90 R⊕ BD-210397 c 12.90 R⊕ HD 95086 b 12.90 R⊕

Metric	Earth	HD 55696 b	Jupiter
Radius (R⊕)	1.00	12.90	11.21
Mass (M⊕)	1.00	1,357.13	317.83
Density (g/cm³)	5.51	3.47	1.33
Surface Gravity (g)	1.00	8.16	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	1,357.127 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	1,230.002 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 55696

HIP

HIP 34801

TIC

TIC 22598327

Gaia DR2

Gaia DR2 5565208310497615232

Gaia DR3

Gaia DR3 5565208310497615232

System

HD 55696

Percentile among Gas Giant cohort

Radius 12.900 R⊕ · percentile 41 / cohort 1771

Mass 1,357.127 M⊕ · percentile 72 / cohort 1747

Orbital period 1,827.00 d · percentile 84 / cohort 1533

Distance 77.97 pc · percentile 30 / cohort 1759

ESI 0.422 · percentile 92 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

1,827.000 days

Semi-major axis

3.1800 AU

Eccentricity

0.705

Inclination

57.00 °

Year Length

A year here lasts about 5.00 Earth years on a highly eccentric trajectory at a mean orbital distance of 3.1800 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.422

0 = alien, 1 = Earth-identical

Detection Signatures

Radial velocity

Stellar wobble has been measured spectroscopically.

Astrometry

Positional wobble of the host star was measured.

Discovery Paper

Primary reference

Ment et al. 2018

Instrument

HIRES Spectrometer

Publication

2018-11

Observation locale

Ground

Discovery cohort

Planets confirmed in 2018 at W. M. Keck Observatory (12 shown).

HD 75784 c · Gas Giant HD 99706 c · Gas Giant HD 148164 c · Gas Giant HD 95089 c · Gas Giant HD 13167 b · Gas Giant HD 18015 b · Gas Giant HAT-P-11 c · Gas Giant HD 156279 c · Gas Giant HD 98736 b · Gas Giant HD 180053 b · Gas Giant HD 114783 c · Gas Giant HD 72490 b · Gas Giant

Host System: HD 55696

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

6,012 K — hotter than the Sun (5,778 K)

Estimated Age

2.64 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.520 R☉

Stellar Mass

1.290 M☉

Metallicity [Fe/H]

0.37

Extended Stellar Properties

Surface gravity (log g)

4.150 dex

Stellar density

0.325 g/cm³

Systemic radial velocity

19.72 km/s

Rotational v·sin i

7.00 km/s

Metallicity ratio

[Fe/H]

Distance

77.97 parsec

Light-years 254.30 ly

V-band magnitude

7.95 mag

Voyager-speed travel 4,484,608 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

12.797 mas

Total Proper Motion

39.003 mas/yr

PM Right Ascension

-31.52 mas/yr

PM Declination

-22.98 mas/yr

Galactic Cartesian (pc)

x = -0.244 · y = 0.747 · z = -0.618

Equatorial (J2000)

RA 108.06220° · Dec -38.17464°

Galactic ℓ, b

249.586° · -12.614°

Ecliptic λ, β

118.988° · -59.809°

HTM-20 index

-254800456