CoRoT-2a is a young (about 0.5 Gyr) G7V star accompanied by a transiting hot-Jupiter, discovered by the CoRoT satellite (Alonso et al. 2008; Bouchy et al. 2008). An analysis of its photospheric activity, based on spot modelling techniques previously
developed by our group for the analysis of the Sun as a star, shows that the active regions on CoRoT-2a arised within two active longitudes separated by about 180 degrees and rotating with periods of 4.5221 and 4.5543 days, respectively, at epoch of CoRoT observations (112 continous days centered at 2007.6). We show that the total spotted area oscillates with a period of about about 8.9 days, a value close to 10 times the synodic period of the planet with respect to the active longitude pattern rotating in 4.5221 days. Moreover, the variance of the stellar flux is modulated in phase with the planet orbital period. This suggests a possible star-planet magnetic interaction, a phenomenon already seen in other extrasolar planetary systems hosting hot-Jupiters.
Dedicated to spectroscopic and imaging observations of the ultraviolet sky, the World Space Observatory for Ultraviolet Project is a Russia led international collaboration presently involving also China, Germany, Italy, Spain and Ukraine. The mission
consists of a 1.7m telescope able to perform: a) high resolution (R greater than 60000) spectroscopy by means of two echelle spectrographs covering the 103-310 nm range; b) long slit (1x75 arcsec) low resolution (R about 1500-2500) spectroscopy using a near-UV channel and a far-UV channel to cover the 102-310nm range; c) deep UV and diffraction limited UV and optical imaging (from 115 to 700 nm). Overall information on the project and on its science objectives are given by other two papers in these proceedings. Here we present the WSO-UV focal plane instruments, their status of implementation, and the expected performances.
World Space Observatory UltraViolet (WSO-UV) is a multipurpose space observatory, made by a 170 cm aperture telescope, capable of UV high-resolution spectroscopy, long slit low-resolution spectroscopy, and deep UV and optical imaging. With a nominal
mission life time of 5 years, and a planned extension to 10 years, from a geosynchronous orbit with an inclination of 51.8 degrees, WSO-UV will provide observations of exceptional importance for the study of many unsolved astrophysical problems. WSO-UV is implemented in the framework of a collaboration between Russia (chair), China, Germany, Italy, Spain, and Ukraine. This book illustrates the results of the feasibility study for the Field Camera Unit (FCU), a multi-spectral radial instrument on the focal plane of WSO-UV. The book provides an overview of the key science topics that are drivers to the participation of the Italian astronomical community in the WSO-UV project. The science drivers here illustrated have been used to define the technical requirements for the conceptual and architectural design of the Field Camera Unit (FCU) focal plane instrument. In Chapter I we show that WSO-UV will give a significant contribution to solve the key astronomical problems individuated by the ASTRONET consortium, and which are driving the European Space Agency Cosmic Vision program. Chapter II elucidates the scientific requirements for WSO-UV FCU instrument, discussed in Chapter I, which are translated in a list of verifiable top level requirements usable to make the conceptual design of the FCU instrument. Chapter III is dedicated to the Field Camera Unit opto-mechanical design, its detectors and electronics subsystems. Finally, Chapter IV outlines the AIV and GSE plans and activities for the FCU instrument.
We present color-magnitude diagrams of the open cluster NGC 2420, obtained from Galaxy Evolution Explorer (GALEX) ultraviolet images in FUV and NUV bands and Sloan Digital Sky Survey (SDSS) u,g,r,i,z photometry. Our goal is to search for and characte
rize hot evolved stars and peculiar objects in this open cluster, as part of a larger project aimed to study a number of open clusters in the Milky Way with GALEX and ground-based data.
