Complex systems made up of more than two stars. A typical multiple system contains three or four stars, but there may be many more. Systems with multiple components tend to stablise into pairs of close binaries, with more distant components orbiting their centre of gravity, but many different combinations can potentially occur.
The central star in this image is Keid or Omicron2 Eridani, a multiple system with three component stars. Keid is a triple system, in which an orangemain-sequence star is orbited by a binary pair of a reddwarf and a white dwarf. These three stars are not individually distinguishable here, but their separation is hinted at by the triple diffraction spikes (the cross-shaped artefacts extending out from the bright spot of the star). Imagery provided by Aladin sky atlas
