The analysis of a long X-ray observation reveals the nature of the mysterious star Wd1-9: a binary system containing a star that has recently evolved into the Wolf-Rayet phase, after expelling the outer layers of its atmosphere, which were accreted onto the companion star. Among the at least one hundred billion stars hosted by our Galaxy, there are a
The amount of gas that is converted into stars by the star formation process is described by the star formation rate. For instance, in the Milky Way today between 0.7 and 1.5 solar masses of gas are converted into stars each year. However, this a mean value across our Galaxy, since locally clouds can start forming stars at higher rates
On June 2019, the panel for the evaluation of the proposals for observations with the NASA telescope Chandra, operating in the X-rays, which met up in Boston, has approved the Large Project: “Star formation in starburst: a deep ACIS-I observation of Westerlund 1“, led by the astronomer Mario Giuseppe Guarcello – INAF Astronomical Observatory of Palermo. More details on the
di Mario Giuseppe Guarcello ( segui mguarce) Poche ma estremamente importanti…. Le stelle con masse maggiori di 6 masse solari ed una temperatura efficace maggiore di 15000 gradi (stelle O e stelle B1-B5) sono particolarmente rare nell’Universo e la loro evoluzione si compie in pochi milioni di anni, un tempo piuttosto breve se paragonato ai miliardi di anni
