Key parameters at a glance

A radius of 13.10 Earth radii
A mass of 1,071.04 Earth masses
Surface gravity around 6.24 g
An orbital period of 133.710 days
Semi-major axis 0.4900 AU
Equilibrium temperature 350 K (77 °C)
Distance from Earth 57.26 light-years
Earth Similarity Index 0.440
Travel time at Voyager 1 speed 1,009,773 years

Context from the literature

GJ 3021 b, also known as Gliese 3021 b or HD 1237 b, is an extrasolar planet approximately 57 light-years away, orbiting its bright G-dwarf parent star in the Southern constellation of Hydrus. It was discovered with the Swiss Euler Telescope at the Chilean La Silla Observatory in 2000.

Excerpted from Wikipedia · full article

GJ 3021 b Planet Profile

Physical Specs

Radius

13.10 R⊕

Radius (Jupiter)

1.170 R♃

Mass

1,071.04 M⊕

Mass (Jupiter)

3.370 M♃

Density

2.62 g/cm³

Surface Gravity

6.24 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.440

HZ Position Unknown

Controversial No

Discovery

Year 2000

Method Radial Velocity

Facility La Silla Observatory

Telescope 1.2 m Leonhard Euler Telescope

Size rank in cohort

Rank by radius

#910of 1771

top 51.3%

This planet

13.10R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 221287 b 13.10 R⊕ 91 Aqr b 13.10 R⊕ HD 37605 c 13.10 R⊕

Metric	Earth	GJ 3021 b	Jupiter
Radius (R⊕)	1.00	13.10	11.21
Mass (M⊕)	1.00	1,071.04	317.83
Density (g/cm³)	5.51	2.62	1.33
Surface Gravity (g)	1.00	6.24	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	1,071.040 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 1237

HIP

HIP 1292

TIC

TIC 290543478

Gaia DR2

Gaia DR2 4634528720388462592

Gaia DR3

Gaia DR3 4634528720388462592

System

GJ 3021

Percentile among Gas Giant cohort

Radius 13.100 R⊕ · percentile 46 / cohort 1771

Mass 1,071.040 M⊕ · percentile 68 / cohort 1747

Orbital period 133.71 d · percentile 55 / cohort 1533

Distance 17.56 pc · percentile 3 / cohort 1759

ESI 0.440 · percentile 98 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

133.710 days

Semi-major axis

0.4900 AU

Eccentricity

0.511

Inclination

— °

Year Length

A year here lasts approximately 133.71 Earth days (36.6% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.4900 AU.

Eq. Temperature

350K

(77 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.440

0 = alien, 1 = Earth-identical

Insufficient insolation data — liquid water is physically possible with adequate atmospheric pressure.

Discovery Paper

Primary reference

Naef et al. 2001

Instrument

CORALIE Spectrograph

Publication

2001-08

Observation locale

Ground

Host System: GJ 3021

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,540 K — cooler than the Sun (5,778 K)

Estimated Age

0.37 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.900 R☉

Stellar Mass

0.900 M☉

Metallicity [Fe/H]

0.10

Extended Stellar Properties

Surface gravity (log g)

4.700 dex

Stellar density

2.009 g/cm³

Systemic radial velocity

-5.81 km/s

Rotational v·sin i

5.50 km/s

Activity index (log R'HK)

-4.440

Metallicity ratio

[Fe/H]

Distance

17.56 parsec

Light-years 57.26 ly

V-band magnitude

6.59 mag

Voyager-speed travel 1,009,773 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

56.932 mas

Total Proper Motion

437.548 mas/yr

PM Right Ascension

433.91 mas/yr

PM Declination

-56.32 mas/yr

Galactic Cartesian (pc)

x = 0.176 · y = 0.012 · z = -0.984

Equatorial (J2000)

RA 4.06343° · Dec -79.85142°

Galactic ℓ, b

304.869° · -37.144°

Ecliptic λ, β

294.812° · -65.243°

HTM-20 index

176488318

Observation Record

Photometric series

RV measurements

Archive notes

Wikipedia → Image: Wikimedia Commons · Exoplanetedu95 · CC BY-SA 3.0