Key parameters at a glance

A radius of 12.70 Earth radii
A mass of 2,097.67 Earth masses
Surface gravity around 13.01 g
An orbital period of 913.000 days
Semi-major axis 2.1300 AU
Distance from Earth 46.00 light-years
Earth Similarity Index 0.440
Travel time at Voyager 1 speed 811,136 years

gam Cep b Planet Profile

Physical Specs

Radius

12.70 R⊕

Radius (Jupiter)

1.130 R♃

Mass

2,097.67 M⊕

Mass (Jupiter)

6.600 M♃

Density

5.63 g/cm³

Surface Gravity

13.01 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.440

HZ Position Unknown

Controversial No

Discovery

Year 2003

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#1130of 1771

top 63.7%

This planet

12.70R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 168863 b 12.70 R⊕ HD 233604 b 12.70 R⊕ Kepler-424 c 12.70 R⊕

Metric	Earth	gam Cep b	Jupiter
Radius (R⊕)	1.00	12.70	11.21
Mass (M⊕)	1.00	2,097.67	317.83
Density (g/cm³)	5.51	5.63	1.33
Surface Gravity (g)	1.00	13.01	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2,097.667 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	448.138 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 222404

HIP

HIP 116727

TIC

TIC 367912480

Gaia DR2

Gaia DR2 2281778105591104768

Gaia DR3

Gaia DR3 2281778105594488192

System

gam Cep

Percentile among Gas Giant cohort

Radius 12.700 R⊕ · percentile 34 / cohort 1771

Mass 2,097.667 M⊕ · percentile 81 / cohort 1747

Orbital period 913.00 d · percentile 76 / cohort 1533

Distance 14.10 pc · percentile 2 / cohort 1759

ESI 0.440 · percentile 98 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

913.000 days

Semi-major axis

2.1300 AU

Eccentricity

0.150

Inclination

— °

Year Length

A year here lasts about 2.50 Earth years on a mildly elliptical path at a mean orbital distance of 2.1300 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

25.600 m/s

Transit mid-time (BJD)

2,453,117.0000

Long. of periastron (ω)

49.00°

Angular separation (arcsec)

151.00000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.440

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

Hatzes et al. 2003

Instrument

Multiple Instruments

Publication

2003-12

Observation locale

Ground

Host System: gam Cep

Spectral Class

K-type orange

Effective Temperature

4,775 K — cooler than the Sun (5,778 K)

Estimated Age

5.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

4.740 R☉

Stellar Mass

1.270 M☉

Metallicity [Fe/H]

0.18

Extended Stellar Properties

Surface gravity (log g)

3.189 dex

Rotational v·sin i

0.00 km/s

Metallicity ratio

[Fe/H]

Distance

14.10 parsec

Light-years 46.00 ly

V-band magnitude

3.23 mag

Voyager-speed travel 811,136 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

70.910 mas

Total Proper Motion

136.125 mas/yr

PM Right Ascension

-49.00 mas/yr

PM Declination

127.00 mas/yr

Galactic Cartesian (pc)

x = 0.213 · y = -0.019 · z = 0.977

Equatorial (J2000)

RA 354.83582° · Dec 77.63310°

Galactic ℓ, b

118.992° · 15.316°

Ecliptic λ, β

60.091° · 64.670°

HTM-20 index

1027761836

Observation Record

Photometric series

RV measurements

Stellar spectra

Archive notes

Similar Worlds

HD 168863 b

Gas Giant · K-type orange

Radius 12.70 R⊕ · 130.1 ly

HD 27894 d

Gas Giant · K-type orange

Radius 12.70 R⊕ · 142.9 ly

HIP 56640 b

Gas Giant · K-type orange

Radius 12.70 R⊕ · 399.0 ly

eps CrB b

Gas Giant · K-type orange

Radius 12.70 R⊕ · 227.9 ly

HIP 67851 c

Gas Giant · K-type orange

Radius 12.70 R⊕ · 209.1 ly

HD 113996 b

Gas Giant · K-type orange

Radius 12.70 R⊕ · 379.4 ly

Explore Related Categories

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