Confirmed Exoplanet Discovered 2011

GJ 433 b

A sub-neptune orbiting the m-type red dwarf GJ 433, located approximately 29.6 light-years from Earth.

Key parameters at a glance

  • A radius of 2.33 Earth radii
  • A mass of 6.04 Earth masses
  • Surface gravity around 1.11 g
  • An orbital period of 7.371 days
  • Semi-major axis 0.0620 AU
  • Distance from Earth 29.56 light-years
  • Earth Similarity Index 0.730
  • Travel time at Voyager 1 speed 521,372 years
  • Almost certainly tidally locked to its host star given the close orbit

Context from the literature

Gliese 433 is a dim red dwarf star with multiple exoplanetary companions, located in the equatorial constellation of Hydra. The system is located at a distance of 29.6 light-years from the Sun based on parallax measurements, and it is receding with a radial velocity of +18 km/s. Based on its motion through space, this is an old disk star. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 9.81 and an absolute magnitude of 10.07.

Excerpted from Wikipedia · full article

2 siblings around GJ 433

GJ 433 b 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 this Sub-Neptune 2.33 6.04 7.371 2011
GJ 433 d Sub-Neptune 2.14 5.22 36.059 2020
GJ 433 c Neptune-like 6.27 32.42 5,094.105 2014

GJ 433 b Planet Profile

Physical Specs

Radius
2.33 R⊕
Radius (Jupiter)
0.208 R♃
Mass
6.04 M⊕
Mass (Jupiter)
0.019 M♃
Density
2.63 g/cm³
Surface Gravity
1.11 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.730
HZ Position Unknown
Controversial No

Discovery

Year 2011
Method Radial Velocity
Facility La Silla Observatory
Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#1451of 1978

top 73.3%

This planet

2.33R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth GJ 433 b Jupiter
Radius (R⊕)1.002.3311.21
Mass (M⊕)1.006.04317.83
Density (g/cm³)5.512.631.33
Surface Gravity (g)1.001.112.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Minimum mass (M sin i) 6.043 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 2.330 R⊕ · percentile 26 / cohort 1978
Mass 6.043 M⊕ · percentile 26 / cohort 1978
Orbital period 7.37 d · percentile 24 / cohort 1946
Distance 9.06 pc · percentile 1 / cohort 1975
ESI 0.730 · percentile 95 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
7.371 days
Semi-major axis
0.0620 AU
Eccentricity
0.040
Inclination
°

Year Length

A year here lasts approximately 7.37 Earth days (2.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0620 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.730

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Bonfils et al. 2013

Instrument

HARPS Spectrograph

Publication

2013-01

Observation locale

Ground

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

5.211.211.20B9.81V8.89Gaia7.81TESS7.65Ic6.47J5.86H5.62K5.45W15.21W25.34W35.20W4

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

1

RV measurements

1

Stellar spectra

1

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