Key parameters at a glance

A radius of 11.78 Earth radii
A mass of 6,991.57 Earth masses
Surface gravity around 50.41 g
Semi-major axis 773.0000 AU
Distance from Earth 59.09 light-years
Earth Similarity Index 0.275
Travel time at Voyager 1 speed 1,042,139 years

HN Peg b Planet Profile

Physical Specs

Radius

11.78 R⊕

Radius (Jupiter)

1.051 R♃

Mass

6,991.57 M⊕

Mass (Jupiter)

21.999 M♃

Density

23.50 g/cm³

Surface Gravity

50.41 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.275

HZ Position Unknown

Controversial No

Discovery

Year 2006

Method Imaging

Facility Spitzer Space Telescope

Telescope 0.85 m Spitzer Space Telescope

Size rank in cohort

Rank by radius

#1561of 1771

top 88.1%

This planet

11.78R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

EPIC 246851721 b 11.78 R⊕ Kepler-75 b 11.77 R⊕ CoRoT-23 b 11.77 R⊕

Metric	Earth	HN Peg b	Jupiter
Radius (R⊕)	1.00	11.78	11.21
Mass (M⊕)	1.00	6,991.57	317.83
Density (g/cm³)	5.51	23.50	1.33
Surface Gravity (g)	1.00	50.41	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	6,991.570 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

HD 206860

HIP

HIP 107350

TIC

TIC 301880196

Gaia DR2

Gaia DR2 1772187382746856320

Gaia DR3

Gaia DR3 1772187382746856320

System

HN Peg

Percentile among Gas Giant cohort

Radius 11.777 R⊕ · percentile 12 / cohort 1771

Mass 6,991.570 M⊕ · percentile 98 / cohort 1747

Distance 18.12 pc · percentile 3 / cohort 1759

ESI 0.275 · percentile 51 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

— days

Semi-major axis

773.0000 AU

Eccentricity

—

Inclination

— °

Year Length

Orbital period for this planet has not yet been measured.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.275

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Luhman et al. 2007

Instrument

IRAC Infrared Array Camera

Publication

2007-01

Observation locale

Space

Host System: HN Peg

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

6,186 K — hotter than the Sun (5,778 K)

Estimated Age

0.30 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.007 R☉

Stellar Mass

1.080 M☉

Metallicity [Fe/H]

-0.04

Extended Stellar Properties

Surface gravity (log g)

4.480 dex

Stellar density

1.475 g/cm³

Systemic radial velocity

-17.20 km/s

Rotational v·sin i

10.00 km/s

Rotation period

4.50 days

Activity index (log R'HK)

-4.420

Metallicity ratio

[M/H]

Distance

18.12 parsec

Light-years 59.09 ly

V-band magnitude

5.98 mag

Voyager-speed travel 1,042,139 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

55.163 mas

Total Proper Motion

257.293 mas/yr

PM Right Ascension

231.09 mas/yr

PM Declination

-113.13 mas/yr

Galactic Cartesian (pc)

x = 0.803 · y = -0.539 · z = 0.255

Equatorial (J2000)

RA 326.13157° · Dec 14.77145°

Galactic ℓ, b

69.860° · -28.270°

Ecliptic λ, β

333.916° · 26.633°

HTM-20 index

575057735

Observation Record

Photometric series

Stellar spectra

Archive notes