PLANETARY ORBITS IN THE ELLIPTIC RESTRICTED PROBLEM .3. THE ETA-CORONAE-BOREALIS SYSTEM

Numerical simulations are made within the frame of the elliptic plane restricted three-body problem, in order to search if stable orbits exi st for planets around one of the two components in double stars. The e ta Coronae Borealis system is investigated here. Large stable planetar y orbits, already known to exist through a systematic exploration of t he circular model and for the Sun-Jupiter, the alpha Centauri and the Sirius elliptic cases, are found to exist around eta CrB A and eta CrB B up to distances from each star of the order of more than half the b inary's periastron separation. Moreover, nearly circular stable planet ary orbits are found to exist in the so-called ''habitable zone'' arou nd each star.