NGC4321 is a two-armed grand design spiral galaxy in the Virgo Cluster. HI emission line data with 15 arcsecond resolution from the VLA map the velocity field of the hydrogen gas in the disk of NGC4321. In a grand design spiral galaxy, the presence of a spiral density wave causes deviations from circular rotation in the gas. The observed velocity

We present improved visual and near-infrared empirical mass-luminosity relations for very low mass stars (M

We have photometrically searched the circumstellar habitable zone (about 95 eclipsing binary system CM Draconis for evidence of planetary transits. With 1014 hours of imaging data we have reached a detection limit of about 2.3 Earth radii (less than 1 60 days or less, marginally demonstrating that the ground-based detection of large terrestrial

We describe our methods to validate the absolute calibration of the infrared (IR) radiometry of the Midcourse Space Experiment (MSX) Point Source Catalog, version 1.2 (PSC1.2). These are based upon stars drawn from our current all-sky network of absolute calibrators and upon other stars that also support the calibration of ESA's Infrared Space

We simulate the characteristics of the Galactic population of radio and gamma-ray pulsars using Monte Carlo techniques. At birth, neutron stars are spatially distributed with supernova-kick velocities in the Galactic disk and randomly dispersed in age back to 109 years. They are evolved in the Galactic gravitational potential to the present time.

The GOLF instrument provides a stable and continuous measurement of the intensity of spatially integrated sunlight in one wing of the sodium D lines. Because the detected radiation results from atomic scattering, the GOLF signal can be traced to an atomic reference wavelength. The planned operations were to involve a form of relative photometry