Key parameters at a glance

A radius of 5.19 Earth radii
A mass of 23.54 Earth masses
Surface gravity around 0.87 g
An orbital period of 30.599 days
Semi-major axis 0.1434 AU
Distance from Earth 65.85 light-years
Earth Similarity Index 0.466
Travel time at Voyager 1 speed 1,161,298 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

GJ 3293 is a star in the constellation of Eridanus, that is orbited by four planets, two of which are located within the star's habitable zone. It is located at the celestial coordinates: Right Ascension 04h 28m 35.71911s, Declination −25° 10′ 09.2979″. With an apparent visual magnitude of 11.96, this star is too faint to be seen with the naked eye. It can be viewed with a telescope having an aperture of at least 4 in (10 cm). The estimated distance to GJ 3293 is 65.9 light-years, based on its stellar parallax. GJ 3293 is significantly smaller and cooler than the Sun.

Excerpted from Wikipedia · full article

3 siblings around GJ 3293

GJ 3293 b shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
GJ 3293 e	Super-Earth	1.63	3.28	13.254	—	2017
GJ 3293 b this	Neptune-like	5.19	23.54	30.599	—	2015
GJ 3293 d	Sub-Neptune	2.67	7.60	48.135	—	2017
GJ 3293 c	Neptune-like	4.87	21.09	122.620	—	2015

GJ 3293 b Planet Profile

Physical Specs

Radius

5.19 R⊕

Radius (Jupiter)

0.463 R♃

Mass

23.54 M⊕

Mass (Jupiter)

0.074 M♃

Density

0.93 g/cm³

Surface Gravity

0.87 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.466

HZ Position Habitable

Controversial No

Discovery

Year 2015

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#359of 574

top 62.4%

This planet

5.19R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

KMT-2017-BLG-1057L b 5.19 R⊕ MOA-2008-BLG-310L b 5.18 R⊕ TOI-1710 b 5.20 R⊕

Metric	Earth	GJ 3293 b	Jupiter
Radius (R⊕)	1.00	5.19	11.21
Mass (M⊕)	1.00	23.54	317.83
Density (g/cm³)	5.51	0.93	1.33
Surface Gravity (g)	1.00	0.87	2.53
Insolation (S⊕)	1.00	1.07	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	23.540 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 178872239

Gaia DR2

Gaia DR2 4893118771316702720

Gaia DR3

Gaia DR3 4893118771316702720

System

GJ 3293

Percentile among Neptune-like cohort

Radius 5.190 R⊕ · percentile 37 / cohort 574

Mass 23.540 M⊕ · percentile 39 / cohort 574

Orbital period 30.60 d · percentile 60 / cohort 524

Distance 20.19 pc · percentile 6 / cohort 572

ESI 0.466 · percentile 84 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

30.599 days

Semi-major axis

0.1434 AU

Eccentricity

0.060

Inclination

— °

Year Length

A year here lasts approximately 30.60 Earth days (8.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1434 AU.

Eq. Temperature

—

Insolation (S⊕)

1.07

Earth = 1.00

Earth Similarity (ESI)

0.466

0 = alien, 1 = Earth-identical

Within the conservative habitable zone. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Astudillo Defru et al. 2015

Instrument

HARPS Spectrograph

Publication

2015-03

Observation locale

Ground

Discovery cohort

Planets confirmed in 2015 at La Silla Observatory (10 shown).

Wolf 1061 b · Rocky Terrestrial Wolf 1061 c · Super-Earth HD 1461 c · Sub-Neptune GJ 3341 b · Sub-Neptune Wolf 1061 d · Sub-Neptune HD 204313 c · Neptune-like GJ 3293 c · Neptune-like WASP-41 c · Gas Giant HD 175607 b · Unclassified WASP-47 c · Unclassified

Host System: GJ 3293

Spectral Class

M-type red dwarf

Effective Temperature

3,466 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.404 R☉

Stellar Mass

0.420 M☉

Metallicity [Fe/H]

0.02

Extended Stellar Properties

Surface gravity (log g)

4.781 dex

Stellar density

6.900 g/cm³

Systemic radial velocity

13.30 km/s

Rotation period

41.00 days

Metallicity ratio

[Fe/H]

Distance

20.19 parsec

Light-years 65.85 ly

V-band magnitude

11.95 mag

Voyager-speed travel 1,161,298 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

49.500 mas

Total Proper Motion

492.254 mas/yr

PM Right Ascension

-81.43 mas/yr

PM Declination

-485.47 mas/yr

Galactic Cartesian (pc)

x = 0.351 · y = 0.834 · z = -0.425

Equatorial (J2000)

RA 67.14844° · Dec -25.17134°

Galactic ℓ, b

223.541° · -41.613°

Ecliptic λ, β

59.468° · -46.218°

HTM-20 index

-540982232

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