We report the detection of two planetary mass companions to the solar-type star HD 155358 .
The two planets have orbital periods of 195.0 and 530.3 days , with eccentricities of 0.11 and 0.18 .
The minimum masses for these planets are 0.89 and 0.50 M _ { J } respectively .
The orbits are close enough to each other , and the planets are sufficiently massive , that the planets are gravitationally interacting with each other , with their eccentricities and arguments of periastron varying with periods of 2300–2700 years .
While large uncertainties remain in the orbital eccentricities , our orbital integration calculations indicate that our derived orbits would be dynamically stable for at least 10 ^ { 8 } years .
With a metallicity [ Fe/H ] of -0.68 , HD 155358 is tied with the K1III giant planet host star HD 47536 for the lowest metallicity of any planet host star yet found .
Thus , a star with only 21 % of the heavy-element content of our Sun was still able to form a system of at least two Jovian-mass planets and have their orbits evolve to semi-major axes of 0.6–1.2 AU .