Key parameters at a glance

A radius of 9.52 Earth radii
A mass of 65.90 Earth masses
Surface gravity around 0.73 g
An orbital period of 84.288 days
Semi-major axis 0.3620 AU
Distance from Earth 95.02 light-years
Earth Similarity Index 0.316
Travel time at Voyager 1 speed 1,675,649 years

HD 21411 b Planet Profile

Physical Specs

Radius

9.52 R⊕

Radius (Jupiter)

0.850 R♃

Mass

65.90 M⊕

Mass (Jupiter)

0.207 M♃

Density

0.42 g/cm³

Surface Gravity

0.73 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.316

HZ Position Unknown

Controversial No

Discovery

Year 2019

Method Radial Velocity

Facility Las Campanas Observatory

Telescope 6.5 m Magellan II Clay Telescope

Size rank in cohort

Rank by radius

#45of 574

top 7.7%

This planet

9.52R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

TOI-6695 b 9.53 R⊕ WASP-182 b 9.53 R⊕ WASP-144 b 9.53 R⊕

Metric	Earth	HD 21411 b	Jupiter
Radius (R⊕)	1.00	9.52	11.21
Mass (M⊕)	1.00	65.90	317.83
Density (g/cm³)	5.51	0.42	1.33
Surface Gravity (g)	1.00	0.73	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	65.900 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 21411

HIP

HIP 16012

TIC

TIC 142875660

Gaia DR2

Gaia DR2 5056511692465250304

Gaia DR3

Gaia DR3 5056511692465250304

System

HD 21411

Percentile among Neptune-like cohort

Radius 9.520 R⊕ · percentile 92 / cohort 574

Mass 65.900 M⊕ · percentile 82 / cohort 574

Orbital period 84.29 d · percentile 78 / cohort 524

Distance 29.13 pc · percentile 9 / cohort 572

ESI 0.316 · percentile 54 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

84.288 days

Semi-major axis

0.3620 AU

Eccentricity

0.400

Inclination

— °

Year Length

A year here lasts approximately 84.29 Earth days (23.1% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.3620 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.316

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Feng et al. 2019

Instrument

Carnegie Planet Finder Spectrograph

Publication

2019-06

Observation locale

Ground

Discovery cohort

Planets confirmed in 2019 at Las Campanas Observatory (12 shown).

HD 39855 b · Sub-Neptune HIP 54373 b · Sub-Neptune HD 103949 b · Sub-Neptune HD 24085 b · Sub-Neptune HIP 54373 c · Sub-Neptune HIP 35173 b · Sub-Neptune HD 211970 b · Sub-Neptune HD 64114 b · Neptune-like HIP 71135 b · Neptune-like HD 206255 b · Neptune-like HD 8326 b · Neptune-like HD 102843 b · Gas Giant

Host System: HD 21411

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,605 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.826 R☉

Stellar Mass

0.890 M☉

Metallicity [Fe/H]

-0.27

Extended Stellar Properties

Surface gravity (log g)

4.510 dex

Stellar density

2.405 g/cm³

Systemic radial velocity

17.82 km/s

Rotational v·sin i

2.00 km/s

Metallicity ratio

[M/H]

Distance

29.13 parsec

Light-years 95.02 ly

V-band magnitude

7.88 mag

Voyager-speed travel 1,675,649 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

34.297 mas

Total Proper Motion

314.125 mas/yr

PM Right Ascension

218.07 mas/yr

PM Declination

226.10 mas/yr

Galactic Cartesian (pc)

x = 0.535 · y = 0.674 · z = -0.509

Equatorial (J2000)

RA 51.54742° · Dec -30.61684°

Galactic ℓ, b

228.212° · -56.107°

Ecliptic λ, β

37.838° · -47.337°

HTM-20 index

619351461

Observation Record

Photometric series

Stellar spectra

Archive notes