2006ApJ...647..573G

Two nearby stars, HD 128311 and HD 82943, are believed to host pairs of Jupiter-like planets involved in a strong first-order 2:1 mean motion resonance (MMR). In this work, we reanalyze available radial velocity (RV) measurements and demonstrate that it is also possible to explain the observed RV variations of the parent stars as being induced by a pair of Trojan planets (i.e., in a 1:1 MMR). We show that these Trojan configurations reside in extended zones of stability in which such systems can easily survive in spite of the large masses of the planets, large eccentricities, and nonzero mutual inclinations of their orbits. We also show that HD 82943 could harbor a previously unknown third planet of ∼0.5M_J in ∼2 AU orbit.