M. I. Moretti

The VMC survey – V. First results for classical Cepheids

The VISTA Magellanic Cloud (VMC, PI M.-R. L. Cioni) survey is collecting deep Ks-band time-series photometry of the pulsating variable stars hosted by the system formed by the two Magellanic Clouds (MCs) and the Bridge connecting them. In this paper we present the first results for Classical Cepheids, from the VMC observations of two fields in the Large Magellanic Cloud (LMC), centred on the South Ecliptic Pole and the 30 Doradus star forming regions, respectively. The VMC Ks-band light curves of the Cepheids are well sampled (12 epochs) and of excellent precision (typical errors of � 0.01 mag). We were able to measure for the first time the Ks magnitude of the faintest Classical Cepheids in the LMC (Ks � 17.5 mag), which are mostly pulsating in the First Overtone (FO) mode, and to obtain FO Period–Luminosity (PL), PeriodWesenheit (PW), and Period–Luminosity–Colour (PLC) relations, spanning the full period range from 0.25 to 6 day. Since the longest period Cepheid in our dataset has a variability period of 23 day, we have complemented our sample with literature data for brighter F Cepheids. On this basis we have built a PL relation in the Ks band that, for the first time, includes short period hence low luminosity pulsators, and spans the full range from 1.6 to 100 day in period. We also provide the first ever empirical PW and PLC relations using the (V Ks) colour and time-series Ks photometry. The very small dispersion (� 0.07 mag) of these relations makes them very well suited to study the three-dimensional (3D) geometry of the Magellanic system. The use of “direct” (parallax- and Baade–Wesselink- based) distance measurements to both Galactic and LMC Cepheids, allowed us to calibrate the zero points of the PL, PW, and PLC relations obtained in this paper, and in turn to estimate an absolute distance modulus of (m M)0 = 18.46 ± 0.03 mag for the LMC. This result is in agreement with most of the latest literature determinations based on Classical Cepheids.

New near-infrared period-luminosity-metallicity relations for RR Lyrae stars and the outlook for GAIA

We present results of the analysis of 70 RR Lyrae stars located in the bar of the Large Magellanic Cloud (LMC). Combining spectroscopically determined metallicity of these stars from the literature with precise periods from the OGLE III catalogue and multi-epoch

The VMC survey - x. cepheids, RR lyrae stars and binaries as probes of the magellanic system's structure

K_{\rm s}

The VMC Survey – XIII. Type II Cepheids in the Large Magellanic Cloud

photometry from the VISTA survey of the Magellanic Clouds system (VMC), we derive a new near-infrared period-luminosity-metallicity (

The VMC survey - VII. Reddening map of the 30 Doradus field and the structure of the cold interstellar medium

{\rm PL_{K_{\rm s}}Z}

VARIABLE STARS IN THE ULTRA-FAINT DWARF SPHEROIDAL GALAXY URSA MAJOR I

) relation for RR Lyrae variables. In order to fit the relation we use a fitting method developed specifically for this study. The zero-point of the relation is estimated in two different ways: by assuming the value of the distance to the LMC and by using Hubble Space Telescope (HST) parallaxes of five RR Lyrae stars in the Milky Way (MW). The difference in distance moduli derived by applying these two approaches is

The VMC Survey – VIII. First results for anomalous Cepheids

\sim0.2

THE VMC SURVEY. XIX. CLASSICAL CEPHEIDS in the SMALL MAGELLANIC CLOUD

mag. To investigate this point further we derive the

The VMC survey - IX. Pilot study of the proper motion of stellar populations in the LMC from 2MASS and VISTA data

{\rm PL_{K_{\rm s}}Z}

The VMC survey - I. Strategy and first data

relation based on 23 MW RR Lyrae stars which had been analysed in Baade-Wesselink studies. We compared the derived