Key parameters at a glance

A radius of 12.00 Earth radii
A mass of 7,278.27 Earth masses
Surface gravity around 50.54 g
An orbital period of 10,090.000 days
Semi-major axis 10.1500 AU
Distance from Earth 101.57 light-years
Earth Similarity Index 0.275
Travel time at Voyager 1 speed 1,791,185 years

HD 221420 b Planet Profile

Physical Specs

Radius

12.00 R⊕

Radius (Jupiter)

1.070 R♃

Mass

7,278.27 M⊕

Mass (Jupiter)

22.900 M♃

Density

23.10 g/cm³

Surface Gravity

50.54 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.275

HZ Position Unknown

Controversial No

Discovery

Year 2019

Method Radial Velocity

Facility Anglo-Australian Telescope

Telescope 3.9 m Anglo-Australian Telescope

Size rank in cohort

Rank by radius

#1494of 1771

top 84.3%

This planet

12.00R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

TOI-3757 b 12.00 R⊕ HD 80913 b 12.00 R⊕ HIP 78530 b 12.00 R⊕

Metric	Earth	HD 221420 b	Jupiter
Radius (R⊕)	1.00	12.00	11.21
Mass (M⊕)	1.00	7,278.27	317.83
Density (g/cm³)	5.51	23.10	1.33
Surface Gravity (g)	1.00	50.54	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	7,278.271 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	2,002.319 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 221420

HIP

HIP 116250

TIC

TIC 277890728

Gaia DR2

Gaia DR2 6353376831270492800

Gaia DR3

Gaia DR3 6353376831270492800

System

HD 221420

Percentile among Gas Giant cohort

Radius 12.000 R⊕ · percentile 15 / cohort 1771

Mass 7,278.271 M⊕ · percentile 98 / cohort 1747

Orbital period 10,090.00 d · percentile 95 / cohort 1533

Distance 31.14 pc · percentile 8 / cohort 1759

ESI 0.275 · percentile 51 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

10,090.000 days

Semi-major axis

10.1500 AU

Eccentricity

0.140

Inclination

164.00 °

Year Length

A year here lasts about 27.62 Earth years on a mildly elliptical path at a mean orbital distance of 10.1500 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.275

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

Kane et al. 2019

Instrument

UCLES Spectrograph

Publication

2019-06

Observation locale

Ground

Host System: HD 221420

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,847 K — hotter than the Sun (5,778 K)

Estimated Age

3.65 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.947 R☉

Stellar Mass

1.351 M☉

Metallicity [Fe/H]

0.33

Extended Stellar Properties

Surface gravity (log g)

4.030 dex

Stellar density

0.208 g/cm³

Systemic radial velocity

26.59 km/s

Rotational v·sin i

0.71 km/s

Activity index (log R'HK)

-5.280

Metallicity ratio

[Fe/H]

Distance

31.14 parsec

Light-years 101.57 ly

V-band magnitude

5.82 mag

Voyager-speed travel 1,791,185 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

32.083 mas

Total Proper Motion

16.325 mas/yr

PM Right Ascension

16.30 mas/yr

PM Declination

0.83 mas/yr

Galactic Cartesian (pc)

x = 0.217 · y = -0.025 · z = -0.976

Equatorial (J2000)

RA 353.33190° · Dec -77.38533°

Galactic ℓ, b

308.315° · -38.915°

Ecliptic λ, β

297.795° · -62.282°

HTM-20 index

684743681