Key parameters at a glance

A radius of 13.60 Earth radii
A mass of 479.92 Earth masses
Surface gravity around 2.59 g
An orbital period of 63.330 days
Semi-major axis 0.3300 AU
Distance from Earth 135.87 light-years
Earth Similarity Index 0.342
Travel time at Voyager 1 speed 2,396,138 years

HD 121504 b Planet Profile

Physical Specs

Radius

13.60 R⊕

Radius (Jupiter)

1.210 R♃

Mass

479.92 M⊕

Mass (Jupiter)

1.510 M♃

Density

1.05 g/cm³

Surface Gravity

2.59 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.342

HZ Position Unknown

Controversial No

Discovery

Year 2003

Method Radial Velocity

Facility La Silla Observatory

Telescope 1.2 m Leonhard Euler 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 121504 b	Jupiter
Radius (R⊕)	1.00	13.60	11.21
Mass (M⊕)	1.00	479.92	317.83
Density (g/cm³)	5.51	1.05	1.33
Surface Gravity (g)	1.00	2.59	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	479.923 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 121504

HIP

HIP 68162

TIC

TIC 208844024

Gaia DR2

Gaia DR2 5872266689452551552

Gaia DR3

Gaia DR3 5872266689455300608

System

HD 121504

Percentile among Gas Giant cohort

Radius 13.600 R⊕ · percentile 63 / cohort 1771

Mass 479.923 M⊕ · percentile 48 / cohort 1747

Orbital period 63.33 d · percentile 52 / cohort 1533

Distance 41.66 pc · percentile 15 / cohort 1759

ESI 0.342 · percentile 69 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

63.330 days

Semi-major axis

0.3300 AU

Eccentricity

0.030

Inclination

— °

Year Length

A year here lasts approximately 63.33 Earth days (17.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.3300 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.342

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Mayor et al. 2004

Instrument

CORALIE Spectrograph

Publication

2004-02

Observation locale

Ground

Discovery cohort

Planets confirmed in 2003 at La Silla Observatory (11 shown).

HD 169830 c · Gas Giant HD 111232 b · Gas Giant HD 82943 c · Gas Giant HD 142415 b · Gas Giant HD 82943 b · Gas Giant HD 114386 b · Gas Giant HD 19994 b · Gas Giant HD 65216 b · Gas Giant HD 41004 B b · Gas Giant HD 216770 b · Gas Giant HD 6434 b · Gas Giant

Host System: HD 121504

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

6,027 K — hotter than the Sun (5,778 K)

Estimated Age

1.20 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.070 R☉

Stellar Mass

1.620 M☉

Metallicity [Fe/H]

0.15

Extended Stellar Properties

Surface gravity (log g)

4.590 dex

Stellar density

1.216 g/cm³

Systemic radial velocity

19.30 km/s

Rotational v·sin i

2.60 km/s

Metallicity ratio

[Fe/H]

Distance

41.66 parsec

Light-years 135.87 ly

V-band magnitude

7.54 mag

Voyager-speed travel 2,396,138 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

23.975 mas

Total Proper Motion

263.201 mas/yr

PM Right Ascension

-249.17 mas/yr

PM Declination

-84.79 mas/yr

Galactic Cartesian (pc)

x = -0.487 · y = -0.274 · z = -0.829

Equatorial (J2000)

RA 209.31991° · Dec -56.04041°

Galactic ℓ, b

312.084° · 5.657°

Ecliptic λ, β

230.018° · -40.706°

HTM-20 index

-1858776205

Observation Record

Photometric series

RV measurements

Stellar spectra

Archive notes