Nemesis (Isaac Asimov Novel) - Story Notes

Story Notes

The demands of the plot required Asimov to hypothesize a planetary system about a star named Nemesis. At the time of the writing, the name Nemesis was given to a hypothetical companion to Earth's Sun that could provide a mechanism for periodic disturbances of comets in the Oort cloud, which would then fall inwards causing mass extinctions. The red dwarf star in the book turns out not to be this companion; it is simply passing through the Solar System.

Interestingly, the planetary system in the book included a Jovian planet named Megas in a very short-period orbit about its primary star. (Erythro is a moon of Megas.) This was a radical idea in 1989, but was vindicated with the discovery of the first extrasolar planet orbiting a sun-like star (51 Pegasi) in 1995, dubbed "Bellerophon". Furthermore, the first speculated "habitable" planet discovered, Gliese 581 c, orbits a red dwarf star (Gliese 581) located only 20.3 light years from Earth — a notable similarity to the novel wherein Erythro is the first inhabited extra–solar body.

In the foreword of the novel, Asimov stated that Nemesis is not a part of the millieu that consists of the Foundation, Robot, or Empire series. He also stated that he may change his mind on the matter as nothing in the story appears to rule out or contradict any of the later stories. Some have suspected that the radiation from the star Nemesis may have been intended to be another possible reason for the radiation on Earth forcing emigration.