Epsilon Indi
| Epsilon Indi | |
| Stellar characteristics | |
|---|---|
| Constellation | Indus |
| Right ascension (Epoch J2000) | 22h 03m 21.66s |
| Declination (Epoch J2000) | -56° 47' 09.51" |
| Spectral type | K4-5 Ve |
| Distance from Sol | 11.8 ± 0.02 ly |
| Other designations | Eps Ind, HR 8387, Gl 845, Hip 108870, HD 209100, CP(D)-57 10015, SAO 247287, FK5 825, LHS 67, LTT 8813, LFT 1677. |
Epsilon Indi is a orange-red main sequence dwarf star of spectral and luminosity type K4-5 Ve. The star has about 70 to 77 percent of Sol's mass (RECONS; and NASA Star and Exoplanet Database, from David F. Gray, 1992), 68 to 76 percent of its diameter (Johnson and Wright, 1983, page 701; and NASA Star and Exoplanet Database, from Kenneth R. Lang, 1980), and about 14.7 percent of its visual luminosity and 20.4 percent of its theoretical bolometric luminosity, correcting for infrared output (NASA Star and Exoplanet Database, from Kenneth R. Lang, 1980). According to a 2006 study, it appears to be around 87 percent as enriched as Sol with elements heavier than hydrogen ("metallicity") based on its abundance of iron, although earlier studies found a range of 59 to 110 percent of Sol's metallicity (Santos et al, 2006, page 7 for HD 209100; and Cayrel de Strobel et al, 1991, page 310). The star has a rotational period of 22 days (NASA Star and Exoplanet Database).
This star system is located about 11.8 light-years (ly) away from our Sun, Sol, at the northwestern edge of Constellation Indus, the Indian -- southeast of Delta Indi and northwest of Alpha Tucanae. The fifth brightest star in Indus, this star is the title member of the Epsilon Indi stellar moving group. Although smaller and dimmer than Sol, it is clearly visible with the naked eye.
On January 13, 2003, astronomers announced the discovery of a methane brown dwarf companion to this nearby star (ESO and AIP joint press release and API press release in German -- more below). In August 2003, the same team (as well as another team) of astronomers discovered that the brown dwarf had its own brown dwarf companion (Gemini press release). As of late 2003, the two substellar objects are the closest known brown dwarfs to the Solar System.
(Boilerplate from SolStation.com)
