We present deep and accurate optical photometry of the Local Group starburst galaxy IC 10. The photometry is based on two sets of images collected with the Advanced Camera for Surveys and with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. We provide new estimates of the tip of the red giant branch (TRGB) magnitude

Aims: This work aims to provide a theoretical formulation of surface brightness fluctuations (SBF) in the framework of probabilistic population synthesis models that have no deterministic relations between the different stellar components of a population but only relations on average, and to distinguish between the different distributions involved

We present interferometric imaging at 33GHz, with the new superextended configuration of the Very Small Array (VSA), of a very deep decrement in the cosmic microwave background (CMB) temperature. This decrement is located in the direction of the Corona Borealis supercluster, at a position with no known galaxy clusters, and was discovered by a

Since about 2002 the current-generation imaging air Cherenkov telescopes have discovered more than 50 new VHE γ-ray sources. More importantly, new extragalactic source classe have been discovered: radio galaxies, low-peaked BL Lac (LBL) objects, and quasars. BL Lacertae was the first LBL object that has been detected at VHE. With the MAGIC

After three years since the beginning of operation, the MAGIC telescope could observe several GRB events in the prompt and early afterglow phase. Thanks to its innovative design, the telescope could promptly react to incoming GCN alerts and rapidly slew to the burst coordinates within a typical delay of 50 seconds, performing observations with an

The preliminary results of STEPHI 2006 campaign are reported.