Epsilon Indi

The ε Indi system provides a benchmark case for the study of the formation of gas giants and brown dwarfs.

The 1801 star atlas Uranographia, by German astronomer Johann Elert Bode, places ε Indi as one of the arrows being held in the left hand of the Indian.

[15] In 1847, Heinrich Louis d'Arrest compared the position of this star in several catalogues dating back to 1750, and discovered that it possessed a measureable proper motion.

[16] In 1882–3, the parallax of ε Indi was measured by astronomers David Gill and William L. Elkin at the Cape of Good Hope.

[19] ε Indi leads a list, compiled by Margaret Turnbull and Jill Tarter of the Carnegie Institution in Washington, of 17,129 nearby stars most likely to have planets that could support complex life.

[3] The corona of ε Indi A is similar to the Sun, with an X-ray luminosity of 2×1027 ergs s−1 (2×1020 W) and an estimated coronal temperature of 2×106 K. The stellar wind of this star expands outward, producing a bow shock at a distance of 63 AU.

[26] ε Indi A has a space velocity relative to the Sun of 86 km/s,[4][note 1] which is unusually high for what is considered a young star.

[12] The existence of a planetary companion to Epsilon Indi A was suspected since 2002 based on radial velocity observations.

The detected planet's mass and orbit are different from what was predicted based on radial velocity and astrometry observations.

Epsilon Indi with SkyMapper and a Hubble NICMOS image of the brown dwarf binary
Position of Sun and α Centauri in Ursa Major as seen from ε Indi
Artist's conception of the Epsilon Indi system showing Epsilon Indi A and its brown-dwarf binary companions. The labels give the initial minimum measurement of the distance between Epsilon Indi A and the binary.
Epsilon Indi Ab imaged by JWST MIRI . The star marks the position of its host star, whose light is blocked by a coronagraph .