Key parameters at a glance

A radius of 13.90 Earth radii
A mass of 282.87 Earth masses
Surface gravity around 1.46 g
An orbital period of 298.200 days
Semi-major axis 0.8700 AU
Distance from Earth 85.31 light-years
Earth Similarity Index 0.298
Travel time at Voyager 1 speed 1,504,362 years

HD 128356 b Planet Profile

Physical Specs

Radius

13.90 R⊕

Radius (Jupiter)

1.240 R♃

Mass

282.87 M⊕

Mass (Jupiter)

0.890 M♃

Density

0.58 g/cm³

Surface Gravity

1.46 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.298

HZ Position Unknown

Controversial No

Discovery

Year 2016

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#456of 1771

top 25.7%

This planet

13.90R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

24 Sex c 13.90 R⊕ HD 148156 b 13.90 R⊕ HD 134987 c 13.90 R⊕

Metric	Earth	HD 128356 b	Jupiter
Radius (R⊕)	1.00	13.90	11.21
Mass (M⊕)	1.00	282.87	317.83
Density (g/cm³)	5.51	0.58	1.33
Surface Gravity (g)	1.00	1.46	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	282.869 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 128356

HIP

HIP 71481

TIC

TIC 1056530200

Gaia DR2

Gaia DR2 6223838830917236224

Gaia DR3

Gaia DR3 6223838830917236224

System

HD 128356

Percentile among Gas Giant cohort

Radius 13.900 R⊕ · percentile 72 / cohort 1771

Mass 282.869 M⊕ · percentile 31 / cohort 1747

Orbital period 298.20 d · percentile 61 / cohort 1533

Distance 26.15 pc · percentile 6 / cohort 1759

ESI 0.298 · percentile 58 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

298.200 days

Semi-major axis

0.8700 AU

Eccentricity

0.570

Inclination

— °

Year Length

A year here lasts approximately 298.20 Earth days (81.6% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.8700 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.298

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Jenkins et al. 2017

Instrument

Multiple Instruments

Publication

2017-04

Observation locale

Ground

Discovery cohort

Planets confirmed in 2016 at Multiple Observatories (12 shown).

HD 42618 b · Sub-Neptune HD 164922 c · Sub-Neptune HD 224538 b · Gas Giant HD 30177 c · Gas Giant Kepler-56 d · Gas Giant HD 72892 b · Gas Giant HD 147873 b · Gas Giant HIP 8541 b · Gas Giant HD 68402 b · Gas Giant HD 86950 b · Gas Giant HD 165155 b · Gas Giant rho CrB c · Neptune-like

Host System: HD 128356

Spectral Class

K-type orange

Effective Temperature

4,875 K — cooler than the Sun (5,778 K)

Estimated Age

10.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.850 R☉

Stellar Mass

0.650 M☉

Metallicity [Fe/H]

0.17

Extended Stellar Properties

Surface gravity (log g)

4.520 dex

Stellar density

1.732 g/cm³

Rotational v·sin i

1.30 km/s

Metallicity ratio

[Fe/H]

Distance

26.15 parsec

Light-years 85.31 ly

V-band magnitude

8.24 mag

Voyager-speed travel 1,504,362 yr

Multi-band Host Photometry — 9 bands

Astrometric Data

Parallax

38.205 mas

Total Proper Motion

140.796 mas/yr

PM Right Ascension

-18.39 mas/yr

PM Declination

-139.59 mas/yr

Galactic Cartesian (pc)

x = -0.697 · y = -0.570 · z = -0.435

Equatorial (J2000)

RA 219.27028° · Dec -25.80317°

Galactic ℓ, b

330.871° · 31.275°

Ecliptic λ, β

224.955° · -9.944°

HTM-20 index

1876146339

Similar Worlds

HD 2952 b

Gas Giant · K-type orange

Radius 13.90 R⊕ · 359.1 ly

HIP 111909 c

Gas Giant · K-type orange

Radius 13.90 R⊕ · 287.3 ly

HIP 34222 b

Gas Giant · K-type orange

Radius 13.90 R⊕ · 74.5 ly

HIP 65407 c

Gas Giant · K-type orange

Radius 13.90 R⊕ · 201.5 ly

24 Sex c

Gas Giant · K-type orange

Radius 13.90 R⊕ · 235.1 ly

7 CMa c

Gas Giant · K-type orange

Radius 13.90 R⊕ · 64.6 ly

Explore Related Categories

Gas Giant Planets Radial Velocity Discoveries Multiple Observatories Mission K-type orange Hosts