We report on the optical properties of a sample of 30 BL Lac host galaxies in the redshift range 0.03

Infrared images of the Q0957+561 gravitational lens obtained with the Hubble Space Telescope show two large (~5") lensed images of the zs=1.41 quasar host galaxy. Parts of the host galaxy are doubly imaged, like the quasar, while other parts are quadruply imaged. The distortions of the host galaxy offer the best probe yet of the global structure of

We present step-by-step X-ray data analysis procedures as part of the Chandra Multi-wavelength Project. They consist of additional data corrections and data screening post CXC Standard Data Processing Rev 1 and the determination of sources and their X-ray properties. Using 3 deep ACIS imaging fields (MS 1137.5+6625, CL0848.6+4453 and A0620-00) with

We present reliable, serendipitous x-ray detections found in three different deep ACIS imaging fields in two different energy bandpasses. We ran the Chandra X-ray Center's exttt{cell detect} source detection program on a ``soft band'' image (from 0.5 - 2.0 keV) and a ``hard band'' image (from 2.0 - 7.0 keV). The 3 high latitude fields investigated

The signature of the Solar-Cycle appears clearly in the p-mode parameters (Jiménez-Reyes et al. 1998, Libbrecht & Woodard 1990, and Anguera et al. 1992). At present, the study of the p-mode parameter variation is a very active topic in helioseismology where, thanks to projects like BISON, IRIS, GONG, LOWL and MDI, we are able for the first time to

We present results of analyses of observations of the X-ray source 2A 1704+241 with the ROSAT Position Sensitive Proportional Counter (PSPC) and the High Resolution Imager (HRI). 2A 1704+241 was first associated with the M-giant star HD 154791 based upon observations with the HEAO 1 SMC and the {Einstein} IPC and analysis of a spectrum of HD 154791