Through ground-based observations of the Earth's spectrum from California, satellite observations of clouds, and an atmospheric radiative transfer code, we have determined the temporal evolution of the vegetation signature of Earth to characterize one novel approach to this search. We obtained an excellent agreement between models and observations

Ellerman bombs are bright emission features observed in the wings of Hα, usually in the vicinity of magnetic concentrations. Here we show that they can also be detected in the Ca II infrared triplet lines, which are easier to interpret and therefore allow for more detailed diagnostics. We present full Stokes observations of the 849.8 and 854.2 nm

SPARQL is the W3C candidate recommendation query language for RDF. In this paper we address systematically the formal study of SPARQL, concentrating in its graph pattern facility. We consider for this study a fragment without literals and a simple version of filters which encompasses all the main issues yet is simple to formalize. We provide a

Object 944 Hidalgo is one of the asteroids most likely to be an extinct or dormant comet. Hidalgo's Tisserand invariant (T=2.07) suggests very strongly that this object originated either in the Kuiper belt or in the Oort cloud (Weissman et al. 2002). Our latest ground based results show significant rotational variability in the near-infrared

We present a Roche tomography reconstruction of the secondary star in the cataclysmic variable AE Aqr. The tomogram reveals several surface inhomogeneities that are due to the presence of large, cool star-spots. In addition to a number of lower latitude spots, the maps also show the presence of a large, high-latitude spot similar to that seen in

BF theory is a topological theory that can be seen as a natural generalization of 3-dimensional gravity to arbitrary dimensions. Here we show that the coupling to point particles that is natural in three dimensions generalizes in a direct way to BF theory in d dimensions coupled to (d-3)-branes. In the resulting model, the connection is flat except