The GAPS Programme with HARPS-N@TNG II: No giant planets around the metal-poor star HIP 11952

TL;DR

This study used high-precision radial velocity measurements to investigate the presence of giant planets around the metal-poor star HIP 11952, ultimately ruling out previously claimed planets and impacting planet formation theories.

Contribution

The paper provides the first high-precision radial velocity monitoring of HIP 11952, conclusively excluding the existence of previously claimed giant planets around this metal-poor star.

Findings

No giant planets detected around HIP 11952.

Excluded planets with periods of 6.95 and 290 days.

Challenged previous claims of planetary systems around extremely metal-poor stars.

Abstract

In the context of the program Global Architecture of Planetary Systems (GAPS), we have performed radial velocity monitoring of the metal-poor star HIP 11952 on 35 nights over about 150 days using the newly installed high resolution spectrograph HARPS-N at the TNG and HARPS at ESO 3.6m telescope. The radial velocities show a scatter of 7 m/s, compatible with the measurement errors for such a moderately warm metal-poor star (Teff = 6040+-120K; [Fe/H] =-1.9+-0.1). We then 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 and 105.2+-14.7 m/s, respectively, which had recently been announced. This result is important considering that HIP 11952 was thought to be the most metal-poor star hosting a planetary system with giant planets, thus challenging some models of planet formation.