Key parameters at a glance

A radius of 1.26 Earth radii
A mass of 1.86 Earth masses
Surface gravity around 1.16 g
An orbital period of 1.198 days
Semi-major axis 0.0159 AU
Equilibrium temperature 773 K (500 °C)
Distance from Earth 89.25 light-years
Earth Similarity Index 0.407
Travel time at Voyager 1 speed 1,573,935 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around GJ 3473

GJ 3473 b 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 3473 b this	Super-Earth	1.26	1.86	1.198	773	2020
GJ 3473 c	Sub-Neptune	2.63	7.41	15.509	329	2020

GJ 3473 b Planet Profile

Physical Specs

Radius

1.26 R⊕

Radius (Jupiter)

0.113 R♃

Mass

1.86 M⊕

Mass (Jupiter)

0.006 M♃

Density

5.03 g/cm³

Surface Gravity

1.16 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.407

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#1147of 1176

top 97.4%

This planet

1.26R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

K2-203 b 1.27 R⊕ Kepler-1688 b 1.26 R⊕ Kepler-134 c 1.26 R⊕

Metric	Earth	GJ 3473 b	Jupiter
Radius (R⊕)	1.00	1.26	11.21
Mass (M⊕)	1.00	1.86	317.83
Density (g/cm³)	5.51	5.03	1.33
Surface Gravity (g)	1.00	1.16	2.53
Insolation (S⊕)	1.00	59.40	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	1.860 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 452866790

Gaia DR2

Gaia DR2 3094290054327367168

Gaia DR3

Gaia DR3 3094290054327367168

System

GJ 3473

Percentile among Super-Earth cohort

Radius 1.264 R⊕ · percentile 2 / cohort 1176

Mass 1.860 M⊕ · percentile 1 / cohort 1176

Orbital period 1.20 d · percentile 7 / cohort 1164

Distance 27.36 pc · percentile 6 / cohort 1171

ESI 0.407 · percentile 62 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

1.198 days

Semi-major axis

0.0159 AU

Eccentricity

0.000

Inclination

87.95 °

Year Length

A year here lasts approximately 1.20 Earth days (0.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0159 AU.

Transit Fingerprint

Depth

0.115 %

Duration

0.950 h

Impact parameter b

0.336

Rp / R★

0.031840

Transit midpoint (BJD)

2,458,492.2041

Photometric dip

Transit produces a flux drop of 1,150 ppm lasting ≈ 0.95 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031840

Semi-major axis / stellar radius

9.390

Impact parameter (b)

0.336

RV semi-amplitude (K)

2.210 m/s

Transit mid-time (BJD)

2,458,492.2041

Angular separation (arcsec)

0.58100

Eq. Temperature

773K

(500 °C)

Insolation (S⊕)

59.40

Earth = 1.00

Earth Similarity (ESI)

0.407

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Kemmer et al. 2020

Instrument

TESS CCD Array

Publication

2020-10

Observation locale

Space

Discovery cohort

Planets confirmed in 2020 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-700 d · Rocky Terrestrial TOI-237 b · Super-Earth TOI-700 b · Rocky Terrestrial TOI-1266 c · Super-Earth LTT 3780 c · Sub-Neptune TOI-700 c · Sub-Neptune TOI-776 c · Sub-Neptune TOI-942 c · Neptune-like TOI-776 b · Super-Earth TOI-1266 b · Sub-Neptune TOI-540 b · Rocky Terrestrial LHS 1815 b · Rocky Terrestrial

Host System: GJ 3473

Spectral Class

M-type red dwarf

Effective Temperature

3,347 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.364 R☉

Stellar Mass

0.360 M☉

Metallicity [Fe/H]

0.11

Extended Stellar Properties

Surface gravity (log g)

4.810 dex

Stellar density

10.930 g/cm³

Systemic radial velocity

-1.10 km/s

Rotational v·sin i

2.00 km/s

Rotation period

168.30 days

Metallicity ratio

[Fe/H]

Distance

27.36 parsec

Light-years 89.25 ly

V-band magnitude

13.74 mag

Voyager-speed travel 1,573,935 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

36.515 mas

Total Proper Motion

554.722 mas/yr

PM Right Ascension

-403.17 mas/yr

PM Declination

-381.02 mas/yr

Galactic Cartesian (pc)

x = -0.508 · y = 0.859 · z = 0.058

Equatorial (J2000)

RA 120.59361° · Dec 3.33716°

Galactic ℓ, b

218.151° · 17.288°

Ecliptic λ, β

122.044° · -16.763°

HTM-20 index

1840367210