Key parameters at a glance

A radius of 13.60 Earth radii
A mass of 472.83 Earth masses
Surface gravity around 2.56 g
An orbital period of 597.064 days
Semi-major axis 1.3649 AU
Distance from Earth 117.37 light-years
Earth Similarity Index 0.340
Travel time at Voyager 1 speed 2,069,852 years

HD 20782 b Planet Profile

Physical Specs

Radius

13.60 R⊕

Radius (Jupiter)

1.210 R♃

Mass

472.83 M⊕

Mass (Jupiter)

1.488 M♃

Density

1.03 g/cm³

Surface Gravity

2.56 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.340

HZ Position Unknown

Controversial No

Discovery

Year 2006

Method Radial Velocity

Facility Anglo-Australian Telescope

Telescope 3.9 m Anglo-Australian Telescope

Size rank in cohort

Rank by radius

#609of 1771

top 34.3%

This planet

13.60R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 19994 b 13.60 R⊕ HD 205739 b 13.60 R⊕ HD 79498 b 13.60 R⊕

Metric	Earth	HD 20782 b	Jupiter
Radius (R⊕)	1.00	13.60	11.21
Mass (M⊕)	1.00	472.83	317.83
Density (g/cm³)	5.51	1.03	1.33
Surface Gravity (g)	1.00	2.56	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	472.830 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 20782

HIP

HIP 15527

TIC

TIC 144503325

Gaia DR2

Gaia DR2 5060104351007433472

Gaia DR3

Gaia DR3 5060104351007433472

System

HD 20782

Percentile among Gas Giant cohort

Radius 13.600 R⊕ · percentile 63 / cohort 1771

Mass 472.830 M⊕ · percentile 47 / cohort 1747

Orbital period 597.06 d · percentile 70 / cohort 1533

Distance 35.99 pc · percentile 11 / cohort 1759

ESI 0.340 · percentile 68 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

597.064 days

Semi-major axis

1.3649 AU

Eccentricity

0.950

Inclination

— °

Year Length

A year here lasts about 1.63 Earth years on a highly eccentric trajectory at a mean orbital distance of 1.3649 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.340

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Jones et al. 2006

Instrument

UCLES Spectrograph

Publication

2006-06

Observation locale

Ground

Discovery cohort

Planets confirmed in 2006 at Anglo-Australian Telescope (3 shown).

HD 159868 b · Gas Giant HD 23127 b · Gas Giant HD 187085 b · Gas Giant

Host System: HD 20782

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,782 K — hotter than the Sun (5,778 K)

Estimated Age

5.53 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.127 R☉

Stellar Mass

1.040 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.351 dex

Stellar density

1.025 g/cm³

Systemic radial velocity

39.89 km/s

Rotational v·sin i

1.70 km/s

Activity index (log R'HK)

-4.910

Metallicity ratio

[M/H]

Distance

35.99 parsec

Light-years 117.37 ly

V-band magnitude

7.36 mag

Voyager-speed travel 2,069,852 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

27.759 mas

Total Proper Motion

355.112 mas/yr

PM Right Ascension

349.06 mas/yr

PM Declination

-65.30 mas/yr

Galactic Cartesian (pc)

x = 0.563 · y = 0.671 · z = -0.483

Equatorial (J2000)

RA 50.01662° · Dec -28.85435°

Galactic ℓ, b

224.803° · -57.277°

Ecliptic λ, β

36.975° · -45.212°

HTM-20 index

-939185268

Observation Record

Photometric series

RV measurements

Archive notes