The study of asteroids that present sporadic cometary activity, is of fundamental importance to address several astronomical problems like the end states of comet nuclei, the abundance of water in main belt asteroids and its role as a possible source of terrestial water. We studied the composition of the surface of asteroid (3200) Phaethon, a

We report the detection of the first extrasolar planet, ET-1 (HD 102195b), using the Exoplanet Tracker (ET), a new-generation Doppler instrument. The planet orbits HD 102195, a young star with solar metallicity that may be part of the local association. The planet imparts radial velocity variability to the star with a semiamplitude of 63.4+/-2.0 m

Constellation-X presents a great leap forward in collecting area over current X-ray observatories and will enable high signal-to-noise studies of X-ray sources that are currently too faint for Chandra and XMM-Newton. Thus Constellation-X remains a high-priority mission in reviews by the National Academies and is the next major X-ray observatory

We have obtained mosaic images of NGC 3109 in the V and I bands on 74 nights, spanning approximately 1 yr. From these data, we have conducted an extensive search for Cepheid variables over the entire field of the galaxy, resulting in the discovery of 113 variables with periods ranging from 3.4 to 31.4 days. In this sample, 76 Cepheids, including

We report on observations of 11 transit events of the transiting extrasolar planet XO-1b by the SuperWASP North observatory. From our data, obtained during 2004 May-September, we find that the XO-1b orbital period is 3.941634 +/- 0.000137 days, the planetary radius is 1.34RJ +/- 0.12RJ, and the inclination is 88.92d +/- 1.04d, in good agreement

The determination of chemical abundances from stellar spectra is considered a mature field of astrophysics. Digital spectra of stars are recorded and processed with standard techniques, much like samples in the biological sciences. Nevertheless, uncertainties typically exceed 20% and are dominated by systematic errors. The first part of this paper