Key parameters at a glance
- A radius of 12.70 Earth radii
- A mass of 2,005.50 Earth masses
- Surface gravity around 12.43 g
- An orbital period of 16,510.000 days
- Semi-major axis 28.4000 AU
- Equilibrium temperature 275 K (2 °C)
- Distance from Earth 11.87 light-years
- Earth Similarity Index 0.525
- Travel time at Voyager 1 speed 209,282 years
Context from the literature
Epsilon Indi Ab is a gas giant exoplanet orbiting the star Epsilon Indi A, about 11.9 light-years away in the constellation of Indus. The planet was confirmed to exist in 2018. It orbits at around 30 AU with a period of around 180 years and a relatively high eccentricity of 0.4, and has a mass around seven times that of Jupiter. It was directly imaged using the James Webb Space Telescope in 2023 and the image was released on 24 July, 2024.
Excerpted from Wikipedia · full article
eps Ind A b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1130of 1771
top 63.7%
This planet
12.70R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | eps Ind A b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 12.70 | 11.21 |
| Mass (M⊕) | 1.00 | 2,005.50 | 317.83 |
| Density (g/cm³) | 5.51 | 5.38 | 1.33 |
| Surface Gravity (g) | 1.00 | 12.43 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 2,005.497 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HD
HD 209100
HIP
HIP 108870
TIC
TIC 231698181
Gaia DR2
Gaia DR2 6412595290592307840
Gaia DR3
Gaia DR3 6412595290592307840
System
eps Ind
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts about 45.20 Earth years on a highly eccentric trajectory at a mean orbital distance of 28.4000 AU.
Eq. Temperature
275K
(2 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.525
0 = alien, 1 = Earth-identical
Insufficient insolation data — liquid water is physically possible with adequate atmospheric pressure.
Detection Signatures
Radial velocity
Stellar wobble has been measured spectroscopically.
Astrometry
Positional wobble of the host star was measured.
Direct imaging
The planet has been imaged directly (rare).
Discovery Paper
Primary reference
Feng et al. 2019Instrument
HARPS Spectrograph
Publication
2019-12
Observation locale
Ground
Discovery cohort
Planets confirmed in 2019 at La Silla Observatory (12 shown).
Host System: eps Ind A
Spectral Class
K-type orange
Effective Temperature
4,760 K — cooler than the Sun (5,778 K)
Estimated Age
3.50 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.679 R☉
Stellar Mass
0.760 M☉
Metallicity [Fe/H]
0.22
Extended Stellar Properties
Surface gravity (log g)
5.250 dex
Stellar density
2.560 g/cm³
Systemic radial velocity
-40.70 km/s
Rotational v·sin i
2.00 km/s
Rotation period
-35.73 days
Activity index (log R'HK)
-4.560
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 8 bands
Astrometric Data
Parallax
274.805 mas
Total Proper Motion
4,708.236 mas/yr
PM Right Ascension
3,967.04 mas/yr
PM Declination
-2,535.76 mas/yr
Galactic Cartesian (pc)
x = 0.478 · y = -0.267 · z = -0.837
Equatorial (J2000)
RA 330.87140° · Dec -56.79690°
Galactic ℓ, b
336.166° · -48.055°
Ecliptic λ, β
309.637° · -41.426°
HTM-20 index
-336533374
Similar Worlds
HD 168863 b
Gas Giant · K-type orange
Radius 12.70 R⊕ · 130.1 ly
HD 27894 d
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HIP 56640 b
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eps CrB b
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HIP 67851 c
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HD 113996 b
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