We present the visible spectrum of asteroid-comet transition object 133P/Elst-Pizarro (7968), the first member of the new population of objects called Main Belt Comets (Hsieh & Jewitt 2006). The spectrum was obtained with the 4.2m William Herschel Telescope at the “Roque de los Muchachos” observatory. The orbital elements of 133P place it within

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The ARENA consortium proposes the construction and operation of a 2 meter class telescope at Dôme C dedicated to wide field imaging, and driven by major astrophysical key projects. We present here the foreseen contribution of the Observatoire de Lyon, concerning the data management and the databases.

We describe a scenario for the topology of the magnetic field in penumbrae that accounts for recent observations showing upflows, downflows, and reverse magnetic polarities. According to our conjecture, short narrow magnetic loops fill the penumbral photosphere. Flows along these arched field lines are responsible for both the Evershed effect and

Here we present the methodology we have devised to study the spatial distribution of Massive Star Formation in galaxies. We show results of our analysis performed on a sample of 4,503 galaxies in a range of redshifts extending up to z˜1.2, in the Chandra Deep Field South. We use data from GOODS-HST and COMBO17. The aim is to produce techniques

The purpose of this work is to quantify the ionizing photon budget in the HII regions, deriving the fraction of the Lyman continuum (Lyc) absorbed by dust or escaping from the regions. An underlying aim is to explore the degree of inhomogeneity of a typical HII region.