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We present B and V time series photometry of the M31 satellite galaxy Andromeda XXVII (And XXVII) that we observed with the Large Binocular Cameras of the Large Binocular Telescope. In the field of And XXVII we have discovered a total of 90 variables: 89 RR Lyrae stars and 1 Anomalous Cepheid. The average period of the fundamental mode RR Lyrae stars (RRab) $langle$P$_{rm ab}rangle$=0.59 d ($sigma$=0.05 d) and the period-amplitude diagram place And XXVII in the class of Oosterhoff I/Intermediate objects. Combining information from the color-magnitude diagram (CMD) and the variable stars we find evidence for a single old and metal poor stellar population with [Fe/H]$sim -1.8$ dex and t$sim$13 Gyr in And XXVII. The spatial distribution of RR Lyrae and red giant branch (RGB) stars gives clear indication that And XXVII is a completely disrupted system. This is also supported by the spread observed along the line of sight in the distance to the RR Lyrae stars. The highest concentration of RGB and RR Lyrae stars is found in a circular area of 4 arcmin in radius, centered about 0.2 degrees in south-east direction from Richardson et al. (2011) center coordinates of And XXVII. The CMD of this region is well defined with a prominent RGB and 15 RR Lyrae stars (out of the 18 found in the region) tracing a very tight horizontal branch at $langle V(RR) rangle$ = 25.24 mag $sigma$= 0.06 mag (average over 15 stars). We show that And XXVII well proposes as a candidate building block of the M31 halo.
B and V time-series photometry of the M31 dwarf spheroidal satellite Andromeda XXI (And XXI) was obtained with the Large Binocular Cameras at the Large Binocular Telescope. We have identified 50 variables in And XXI, of which 41 are RR Lyrae stars (3
We present B and V time-series photometry of Andromeda XXV, the third galaxy in our program on the Andromedas satellites, that we have imaged with the Large Binocular Cameras of the Large Binocular Telescope. The field of Andromeda XXV is found to co
To understand the history and formation mechanisms of galaxies it is crucial to determine their current multidimensional structure. Here we focus on stellar population properties, such as metallicity and [$alpha$/Fe] enhancement. We devise a new tech
We present B,V time-series photometry of Andromeda XIX (And XIX), the most extended (half-light radius of 6.2) of Andromedas dwarf spheroidal companions, that we observed with the Large Binocular Cameras at the Large Binocular Telescope. We surveyed
Terzan 5 is a complex stellar system in the Galactic bulge, harboring stellar populations with very different iron content ({Delta}[Fe/H] ~1 dex) and with ages differing by several Gyrs. Here we present an investigation of its variable stars. We repo