The GAPS programme with HARPS-N at TNG. II. No giant planets around the metal-poor star HIP 11952

In the context of the programme Global Architecture of Planetary Systems (GAPS), we have performed radial velocity monitoring of the metal-poor star HIP 11952 on 35 nights during about 150 days using the newly installed high-resolution spectrograph HARPS-N at the TNG and HARPS at the ESO 3.6 m telescope. The radial velocities show a scatter of 7 m s^-1, compatible with the measurement errors for such a moderately warm metal-poor star (T_eff = 6040 ± 120 K; [Fe/H] = -1.9 ± 0.1). We exclude the presence of the two giant planets with periods of 6.95 ± 0.01 d and 290.0 ± 16.2 d and radial velocity semi-amplitudes of 100.3 ± 19.4 m s^-1 and 105.2 ± 14.7 m s^-1, respectively, which have recently been announced. This result is important because HIP 11952 was thought to be the most metal-poor star hosting a planetary systemwith giant planets, which challenged some models of planet formation.

Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundacion Galileo Galilei of the INAF at the Spanish Observatorio del Roque de los Muchachos of the IAC in the frame of the programme Global Architecture of Planetary Systems (GAPS). Based on observations collected at the La Silla Observatory, ESO (Chile): Program 185.D-0056.Table 1 is available in electronic form at http://www.aanda.org