The object CXOM31 J004245.9+411036, reported as a new X-ray source in ATel #1859 from M31 Chandra observations, is the previously reported XMMU J004245.9+411036 (Pietsch et al. 2008, ATel #1647). We thank W. Pietsch and M. Henze for kindly bringing this clerical error to our attention. This transient source has been observed by various space

NGC 2808 was observed with the Chandra X-ray Observatory and the Chandra Advanced CCD Imaging Spectrometer-Imager (ACIS-I) at its focus on 2007 June 19-21 (28 months after the XMM-Newton observation) for two distinct exposures of 46 and 11 kiloseconds (ks). (1 data file).

We study the role of fundamental constants in an updated recombination scenario. We focus on the time variation of the fine structure constant α, and the electron mass m in the early Universe, and put bounds on these quantities by using data from CMB including WMAP 5-yr release and the 2dFGRS power spectrum. We analyze how the constraints are

Context: Below 1 mHz, the power spectrum of helioseismic velocity measurements is dominated by the spectrum of convective motions (granulation and supergranulation) and it is difficult to detect the low-order acoustic modes and gravity modes. Aims: We attempt to understand more clearly the behavior of solar granulation as a function of observing

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We report high-resolution spectroscopy of 125 field stars previously observed as part of the Sloan Digital Sky Survey and its program for Galactic studies, the Sloan Extension for Galactic Understanding and Exploration (SEGUE). These spectra are used to measure radial velocities and to derive atmospheric parameters, which we compare with those