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Omicron -2 Eridani: no ordinary triple


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About this observation
Nick Hewitt
Time of observation
17/11/2018 - 23:48
40 or Omicron-2 Eridani (Keid)
Observing location
TMB 115mm f7 triplet
Trius 814 CCD
EQ8 mount
Astronomik RGB filters
RGB 10 x 30 sec each averaged

The primary is an undistingished 4th magnitude K-type star low down in the Celestial River; but at 85" distance lie a closer pair that represent the easiest white dwarf and one of the easiest red dwarfs to observe. They are far enough away from the primary that glare is not an issue (unlike the Pups of Sirius and Procyon). Omicron-2B was the first white dwarf to be recognised as such. Omicron-2C is not the brightest red dwarf by any means, but its location makes pinning it down easy. BC are at 8" separation, with a 240 year orbit. Enlarge image to bring out the red dwarf's colour. 

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