The main goal of this work is to analyse new approaches to the study of the properties of astronomical sites. In particular, satellite data measuring aerosols have recently been proposed as a useful technique for site characterization and searching for new sites to host future very large telescopes. Nevertheless, these data need to be critically

APOGEE is a large-scale, NIR, high-resolution (R˜ 20 000) spectroscopic survey of Galactic stars. It is one of the four experiments in SDSS-III. Because APOGEE will observe in the H band, where the extinction is six times smaller than in V, it will be the first survey to pierce through Galactic dust and provide a vast, uniform database of chemical

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