We report on the results of a coordinated observation of Mrk 421 during outburst using data from XMM-Newton and ground-based TeV data from two Imaging Air Cherenkov Telescopes, the Whipple 10m telescope, based in Arizona, and the MAGIC telescope, based on La Palma in the Canary Islands. The coordinated effort between the two TeV groups allowed for

We investigate the assembly histories 56 of galaxy clusters using a pair of cosmological LCDM N-body simulations. We track infalling galaxy subhalos with masses large enough to host 0.1 L* galaxies , and find that the majority of cluster member galaxies experienced no ``pre-processing'' in the group environment prior to their accretion into the

Context: The footpoints of quiet Sun Transition Region (TR) loops do not seem to coincide with the photospheric magnetic structures appearing in traditional low-sensitivity magnetograms. Aims: We look for the so-far unidentified photospheric footpoints of TR loops using G-band bright points (BPs) as proxies for photospheric magnetic field

We present Roche tomograms of the G5-G8 IV/V secondary star in the long-period cataclysmic variable BV Cen reconstructed from Magellan Inamori Kyocera Echelle spectrograph echelle data taken on the Magellan Clay 6.5-m telescope. The tomograms show the presence of a number of large, cool star-spots on BV Cen for the first time. In particular, we

We present results from SEPPCoN, our Survey of Ensemble Physical Properties of Cometary Nuclei. This survey involves studying 100 Jupiter-family comets (JFCs) -- about 30% of the known population -- using the Spitzer Space Telescope for mid-infrared measurements of thermal emission and several ground-based telescopes for visible-wavelength

During orbit DI 016 (October 2005) Cassini's Visual and Infrared Mapping Spectrometer (VIMS) [1] acquired spatially resolved spectral data of the Saturnian satellite Dione with pixel ground resolutions up to 2 km per pixel. Additionally, the Imaging Science Subsystem (ISS) [2] observed the satellite synchronously to VIMS with pixel ground