Confirmed Exoplanet Discovered 2021

GJ 414 A c

A neptune-like orbiting the k-type orange GJ 414 A, located approximately 38.8 light-years from Earth.

Key parameters at a glance

  • A radius of 8.40 Earth radii
  • A mass of 53.83 Earth masses
  • Surface gravity around 0.76 g
  • An orbital period of 749.830 days
  • Semi-major axis 1.4000 AU
  • Equilibrium temperature 125 K (-148 °C)
  • Distance from Earth 38.78 light-years
  • Earth Similarity Index 0.222
  • Travel time at Voyager 1 speed 683,844 years

1 sibling around GJ 414 A

GJ 414 A c shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet Type Radius (R⊕) Mass (M⊕) Period (d) Eq. T (K) Year
GJ 414 A b Sub-Neptune 2.63 7.60 50.800 309 2021
GJ 414 A c this Neptune-like 8.40 53.83 749.830 125 2021

GJ 414 A c Planet Profile

Physical Specs

Radius
8.40 R⊕
Radius (Jupiter)
0.749 R♃
Mass
53.83 M⊕
Mass (Jupiter)
0.169 M♃
Density
0.50 g/cm³
Surface Gravity
0.76 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.222
HZ Position Unknown
Controversial No

Discovery

Year 2021
Method Radial Velocity
Facility W. M. Keck Observatory
Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#129of 574

top 22.3%

This planet

8.40R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Metric Earth GJ 414 A c Jupiter
Radius (R⊕)1.008.4011.21
Mass (M⊕)1.0053.83317.83
Density (g/cm³)5.510.501.33
Surface Gravity (g)1.000.762.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Minimum mass (M sin i) 53.830 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 97101

HIP

HIP 54646

TIC

TIC 9001920

Gaia DR2

Gaia DR2 732857558276385664

Gaia DR3

Gaia DR3 732857558276385664

System

GJ 414

Percentile among Neptune-like cohort

Radius 8.400 R⊕ · percentile 78 / cohort 574
Mass 53.830 M⊕ · percentile 74 / cohort 574
Orbital period 749.83 d · percentile 97 / cohort 524
Distance 11.89 pc · percentile 3 / cohort 572
ESI 0.222 · percentile 33 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
749.830 days
Semi-major axis
1.4000 AU
Eccentricity
0.105
Inclination
°

Year Length

A year here lasts about 2.05 Earth years on a mildly elliptical path at a mean orbital distance of 1.4000 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

5.140 m/s

Transit mid-time (BJD)

2,457,228.0000

Long. of periastron (ω)

74.00°

Angular separation (arcsec)

118.00000

Eq. Temperature

125K

(-148 °C)

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.222

0 = alien, 1 = Earth-identical

Insufficient insolation data — any water would exist as deep ice.

Discovery Paper

Primary reference

Dedrick et al. 2021

Instrument

HIRES Spectrometer

Publication

2021-02

Observation locale

Ground

Discovery cohort

Planets confirmed in 2021 at W. M. Keck Observatory (2 shown).

Host System: GJ 414 A

Spectral Class

K-type orange

Effective Temperature

4,120 K — cooler than the Sun (5,778 K)

Estimated Age

12.40 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.680 R☉

Stellar Mass

0.650 M☉

Metallicity [Fe/H]

0.24

Extended Stellar Properties

Surface gravity (log g)

4.650 dex

Stellar density

2.152 g/cm³

Systemic radial velocity

-17.20 km/s

Rotational v·sin i

3.00 km/s

Metallicity ratio

[Fe/H]

Distance
11.89 parsec
Light-years 38.78 ly
V-band magnitude
8.31 mag
Voyager-speed travel 683,844 yr

Multi-band Host Photometry — 12 bands

4.79.79.69B8.31V7.73Gaia6.92TESS6.74Ic5.76J5.13H4.98K4.85W14.66W24.94W34.88W4

Astrometric Data

Parallax

84.080 mas

Total Proper Motion

623.637 mas/yr

PM Right Ascension

591.62 mas/yr

PM Declination

-197.25 mas/yr

Galactic Cartesian (pc)

x = -0.843 · y = 0.183 · z = 0.507

Equatorial (J2000)

RA 167.77450° · Dec 30.44517°

Galactic ℓ, b

198.372° · 67.813°

Ecliptic λ, β

156.342° · 23.097°

HTM-20 index

1976359464

Observation Record

Photometric series

1

Stellar spectra

2

Archive notes

3

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