The passage of a 'Nemesis'-like object through the planetary system

• Published in: The Astronomical journal 1985-09, Vol.90, p.1876-1882
• Main Author: Hills, J. G.
• Format: Article
• Language: English
• ISSN: 0004-6256
• DOI: 10.1086/113891

The probability that passing stars could have perturbed the hypothetical stellar companion, Nemesis, into an orbit that penetrates the planetary system is about 15 percent. The planetary orbits crossed by Nemesis would become highly eccentric, and some would even become hyperbolic. If Nemesis ejects Jupiter from the solar system, the semimajor axis of the orbit of Nemesis would shrink down to a few hundred AU. The probability of any object in the inner edge of the Oort cloud at a semimajor axis of 20,000 AU having passed inside the orbit of Saturn is about 80 percent. The apparent lack of damage to the planetary orbits implies a low probability of there being any objects more massive than 0.02 solar masses in the inner edge of the Oort comet cloud. However, several objects less massive than 0.01 solar masses or 10 Jupiter masses could pass through the planetary system from the Oort cloud without causing any significant damage to the planetary orbits. The lack of damage to the planetary system also requires that no black dwarf more massive than 0.05 solar masses has entered the planetary system from interstellar space.