Epsilon Indi is a K dwarf with two very different kinds of companion: a giant planet on a decades-long orbit, and - 1,459 AU away - a pair of brown dwarfs orbiting each other. It is one of the very few exoplanets we have an actual photograph of rather than an inference.
Fly there in 3DJWST’s mid-infrared camera imaged Epsilon Indi Ab in 2024 at a temperature near 0 °C. Almost every directly-imaged planet before it was a young, self-luminous furnace; this one is genuinely cold, which is why it took a telescope of JWST’s class to see at all.
Epsilon Indi Ba and Bb are the nearest known brown dwarfs - spectral types T1 and T6 - orbiting each other 1,459 AU from the primary star.
The planet was found through a slow radial-velocity drift plus a Hipparcos-to-Gaia astrometric wobble, then confirmed by direct imaging.
| Spectral type | K5 V |
| Surface temperature | 4,700 K |
| Mass | 0.8 solar masses |
| Radius | 0.713 solar radii |
| Luminosity | 0.239 times the Sun |
| Apparent magnitude | 4.69 |
| Age | about 3.5 billion years |
| Distance from the Sun | 11.9 light-years (3.6 parsecs) |
| Position (J2000) | RA 330.8402°, Dec -56.7860° |
| Constellation | Indus |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| Epsilon Indi Ab | 69.7 years | 15.760 AU | 12.7 R⊕ estimated | 2065.9 M⊕ | Radial Velocity, 2019 |
Values are the NASA Exoplanet Archive’s composite parameters. A radius marked estimated comes from a mass–radius relation; a mass marked minimum is M sin i. Planet sizes and colours in the 3D view are renderings: none of these worlds has been photographed as more than a point of light.