Four New Planets Orbiting Metal-enriched Stars

We report the detection of four new extrasolar planets from the Anglo-Australian Planet Search orbiting the metal-enriched stars HD 73526, HD 76700, HD 30177, and HD 2039. The planetary companion of HD 76700 has a circular orbit with a period of 3.98 days. With M sin i = (0.197 ± 0.017)MJ, or 0.69MSAT, it is one of the lowest minimum mass extrasolar planets yet detected. The remaining planets all have elliptical orbits with periods ranging from 190.5 days to 4.4 yr. All four planets have been found orbiting hosts from a subsample of 20 metal-enriched and faint (V < 9) stars, which was added to the Anglo-Australian Planet Search's magnitude-limited V < 7.5 main sample in 1999 October. These stars were selected for metal enrichment on the basis of their Strömgren photometry, and their enrichment has been subsequently confirmed by detailed spectroscopic analysis.