We present the Pristine survey, a new narrow-band photometric survey focused on the metallicity-sensitive Ca H&K lines and conducted in the Northern hemisphere with the wide-field imager MegaCam on the Canada-France-Hawaii Telescope. This paper reviews our ...
The Time-Domain Spectroscopic Survey (TDSS) is an SDSS-IV eBOSS subproject primarily aimed at obtaining identification spectra of similar to 220,000 optically variable objects systematically selected from SDSS/Pan-STARRS1 multi-epoch imaging. We present a ...
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illu ...
We present [C/Fe] and [N/Fe] abundance ratios and CH(lambda 4300) and S(lambda 3883) index measurements for 94 red giant branch (RGB) stars in the Sculptor dwarf spheroidal galaxy from VLT/VIMOS MOS observations at a resolving power R = 1150 at 4020 A. Thi ...
Stray light contamination reduces considerably the precision of photometric of faint stars for low altitude space-borne observatories. When measuring faint objects, the necessity of coping with stray light contamination arises in order to avoid systematic ...
Context. Fornax is one of the most massive dwarf spheroidal galaxies in the Local Group. The Fornax field star population is dominated by intermediate age stars but star formation was going on over almost its entire history. It has been proposed that Forna ...
We present the results from the first public blind point-spread function (PSF) reconstruction challenge, the GRavitational lEnsing Accuracy Testing 2010 (GREAT10) Star Challenge. Reconstruction of a spatially varying PSF, sparsely sampled by stars, at non- ...
Context. The ESPRI project relies on the astrometric capabilities offered by the PRIMA facility of the Very Large Telescope Interferometer for discovering and studying planetary systems. Our survey consists of obtaining high-precision astrometry for a larg ...
We present abundances for seven stars in the (extremely) low-metallicity tail of the Sculptor dwarf spheroidal galaxy, from spectra taken with X-shooter on the ESO VLT. Targets were selected from the Ca II triplet (CaT) survey of the dwarf abundances and r ...
Context. Since 1998, a planet-search program around main sequence stars within 50 pc in the southern hemisphere has been carried out with the CORALIE echelle spectrograph at La Silla Observatory. Aims. With an observing time span of more than 14 years, the ...
The various projects presented in this thesis contribute to the expansion of our knowledge and understanding of the fundamental processes involved in the formation of a galaxy and its stellar populations. For this purpose, two different techniques are appl ...
Aims. Our purpose is to provide reliable stellar parameters for a significant sample of eclipsing binaries, which are representative of a whole dwarf and metal-poor galaxy. We also aim at providing a new estimate of the mean distance to the SMC and of its ...
