Vol. 622
In section 7. Stellar structure and evolution

First stellar spectroscopy in Leo P

The authors present the first stellar spectroscopy in the low-luminosity dwarf galaxy Leo P obtained with VLT-MUSE . The low oxygen abundance (3% solar) and relative proximity (∼1.6 Mpc) make this system a unique environment in which to investigate the properties of massive stars with near-primordial compositions akin to those in the early Universe. The authors provide the first direct evidence for an O-type star and identify 31 candidate (most likely B-type) massive stars, two carbon stars, and two candidate AGB stars. The stacked MUSE spectra for the next 16 brightest stars on the upper red giant branch show Ca II absorption lines. The MUSE data also reveal two 100 pc-scale ring structures in Hα emission. Lastly, the authors also report serendipitous observations of 20 galaxies in the MUSE data cube, with redshifts ranging from z = 0.39, to a close pair of star-forming galaxies at z=2.5.