MANGOS – II. Five new giant planets orbiting low-mass stars

ABSTRACT Giant planets orbiting low-mass stars on short orbits present a conundrum, as in the most extreme cases their existence cannot be reconciled with current models of core accretion. Therefore, surveys dedicated to finding these rare planets have a key role to play by growing the sample to overcome small number statistics. In this work, we present MANGOS, a programme dedicated to the search for giant objects (planets, brown dwarfs, and low-mass stars) orbiting M dwarfs. We report on the discovery of five new giant planets (TOI-3288 Ab, TOI-4666 b, TOI-5007 b, TOI-5292 Ab, TOI-5916 b) first detected by TESS, and confirmed using ground-based photometry and spectroscopy. The five planets have radii in the range of 0.99–1.12 $\mathrm{R_{Jup}}$, masses between 0.49 and 1.69 $\mathrm{M_{Jup}}$, and orbital periods between 1.43 and 2.91 d. We reveal that TOI-3288 and TOI-5292 are wide binaries, and in the case of TOI-5292, we are able to characterize both stellar components. We demonstrate that the planets presented are suitable for further characterization of their obliquities and atmospheres. We detect a small but significant eccentricity for TOI-5007 b, although for this to be more robust, more observations are needed to fully sample the orbit. Finally, we reveal a correlation between stellar metallicity and planet bulk density for giant planets orbiting low-mass stars.