Key parameters at a glance

A radius of 2.14 Earth radii
A mass of 5.22 Earth masses
Surface gravity around 1.14 g
An orbital period of 36.059 days
Semi-major axis 0.1780 AU
Distance from Earth 29.56 light-years
Earth Similarity Index 0.761
Travel time at Voyager 1 speed 521,372 years
Almost certainly tidally locked to its host star given the close orbit

2 siblings around GJ 433

GJ 433 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
GJ 433 b	Sub-Neptune	2.33	6.04	7.371	—	2011
GJ 433 d this	Sub-Neptune	2.14	5.22	36.059	—	2020
GJ 433 c	Neptune-like	6.27	32.42	5,094.105	—	2014

GJ 433 d Planet Profile

Physical Specs

Radius

2.14 R⊕

Radius (Jupiter)

0.191 R♃

Mass

5.22 M⊕

Mass (Jupiter)

0.016 M♃

Density

2.93 g/cm³

Surface Gravity

1.14 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.761

HZ Position Unknown

Controversial No

Discovery

Year 2020

Method Radial Velocity

Facility Multiple Facilities

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#1755of 1978

top 88.7%

This planet

2.14R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-437 b 2.14 R⊕ Kepler-1403 b 2.14 R⊕ Kepler-813 b 2.14 R⊕

Metric	Earth	GJ 433 d	Jupiter
Radius (R⊕)	1.00	2.14	11.21
Mass (M⊕)	1.00	5.22	317.83
Density (g/cm³)	5.51	2.93	1.33
Surface Gravity (g)	1.00	1.14	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	5.223 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 56528

TIC

TIC 57654763

Gaia DR2

Gaia DR2 3478160727866058368

Gaia DR3

Gaia DR3 3478160727866058368

System

GJ 433

Percentile among Sub-Neptune cohort

Radius 2.140 R⊕ · percentile 11 / cohort 1978

Mass 5.223 M⊕ · percentile 12 / cohort 1978

Orbital period 36.06 d · percentile 78 / cohort 1946

Distance 9.06 pc · percentile 1 / cohort 1975

ESI 0.761 · percentile 98 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

36.059 days

Semi-major axis

0.1780 AU

Eccentricity

0.070

Inclination

— °

Year Length

A year here lasts approximately 36.06 Earth days (9.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1780 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.761

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Feng et al. 2020

Instrument

Multiple Instruments

Publication

2020-01

Observation locale

Ground

Discovery cohort

Planets confirmed in 2020 at Multiple Facilities (2 shown).

GJ 180 d · Sub-Neptune GJ 3082 b · Sub-Neptune

Host System: GJ 433

Spectral Class

M-type red dwarf

Effective Temperature

3,461 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.500 R☉

Stellar Mass

0.480 M☉

Metallicity [Fe/H]

-0.17

Extended Stellar Properties

Surface gravity (log g)

4.810 dex

Stellar density

6.367 g/cm³

Systemic radial velocity

17.53 km/s

Metallicity ratio

[Fe/H]

Distance

9.06 parsec

Light-years 29.56 ly

V-band magnitude

9.81 mag

Voyager-speed travel 521,372 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

110.291 mas

Total Proper Motion

853.618 mas/yr

PM Right Ascension

-70.77 mas/yr

PM Declination

-850.68 mas/yr

Galactic Cartesian (pc)

x = -0.838 · y = 0.090 · z = -0.538

Equatorial (J2000)

RA 173.86192° · Dec -32.54363°

Galactic ℓ, b

284.885° · 27.651°

Ecliptic λ, β

188.898° · -31.965°

HTM-20 index

-971693997

Observation Record

Photometric series

RV measurements

Stellar spectra