We have performed the analysis of the X-ray XMM-Newton spectra of the narrow line Seyfert 1 galaxy UGC 11763 (Mkn 1513). We have studied the EPIC data in the range 0.35-10.0 keV (1.2-35.4 Å) and also the high resolution soft X-ray spectra taken with the Reflection Grating Spectrometers (RGSs) in the range 10-30 Å (0.41-1.2 keV). The principal

The origin of short-lived radioactive nuclei at the time of the formation of the Sun is a much debated mystery in modern astronomy. We show that abundance predictions for massive AGB stars (roughly 6 Msolar) of solar metallicity can self-consistently match the abundances of 26Al, 41Ca, 60Fe, and 107Pd in the early Solar System, as derived from

Frequencies, powers and damping rates of the solar p modes are all observed to vary over the 11-yr solar activity cycle. Here, we show that simultaneous variations in these parameters give rise to a subtle cross-talk effect, which we call the `devil in the detail', that biases p-mode frequencies estimated from analysis of long power frequency

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Aims:We report the discovery of a peculiar object observed serendipitously with XMM-Newton. We present its timing and spectral properties and investigate its optical counterpart. Methods: The light curve of the X-ray source, its spectrum, and the spectrum of the best optical counterpart are presented and analyzed. Results: The X-ray flux decreases

We present results from two Chandra imaging observations of Ross 154, a nearby flaring M dwarf star. During a 61 ks ACIS-S exposure, a very large flare occurred (the equivalent of a solar X3400 event, with LX=1.8×1030 ergs s-1) in which the count rate increased by a factor of over 100. The early phase of the flare shows evidence for the Neupert