... HST . ... HST Overview . ... The GHRS can obtain spectra from about 1150 to 3200 . ... The repeatability of fluxes is even better, being better than 1%; i.e., it is possible to compare measures of the same wavelength in the same star at different times to within 1% for observations with the LSA. ... The source to be observed may be placed in a Large Science Aperture (LSA) or a Small Science Aperture (SSA). ... This means that the SSA is better for obtaining spectra with the best resolution. ...

... The Science Operation Department is composed of Astronomers, Telescope Instruments Operators(TIOs) and Data Handling Administrators(DHAs). ... Astronomers have proposed several methods to quantitatively measure the amount of turbulence above the telescope, which the most common ones is Differential Image Motion Monitor (DIMM). In optical testing, the Hartmann test is the common method to test the quality of optical components. ... Hartmann mask consists of 48 lenses. ...

... We present 5GHz high resolution VLA observations of 2,127 radio-- and X-ray--emitting sources found in both the Green Bank (GB) 5GHz radio catalog and the ROSAT All-Sky Survey (RASS). We report core flux densities and positions accurate to =-0.5". ... This table has 1861 rows and 9 columns giving: Catalog source name, RA and DEC (J2000), observation code, S/N ratio, VLA core flux density at 5 GHz (mJy), Green Bank flux density at 5 GHz (mJy), error in Green Bank flux density (mJy), and Notes. ...

The possibility to have Visitor Instruments at the VLTI has been granted to permit innovative observations by teams using stand-alone instruments, free from a substantial fraction of the requirements for fully automated VLTI general use instruments. In addition, the Visitor Instruments could provide a powerful scientific/technical test bench for new instrumental concepts, eventually to be incorporated later in VLTI facility instruments. ... a thorough technical description of the instrument, . ...

Next: Polarization efficiency: size/shape/orientation effects Up: Optical properties of cosmic Previous: The 2175? feature . To model the interstellar polarization one needs to calculate the forward-transmitted radiation for an ensemble of non-spherical aligned dust grains. ... Let non-polarized stellar radiation passes through a dusty cloud with a homogeneous magnetic field. ... The angle between the line of sight and the magnetic field is ( ). ... where the angle is connected with and ( ). ...

Next: Copying Calibration Tables - Up: Calibration, the ATCA, and Previous: Determining Gains and Bandpass . ... This parameter can be used as an alternative way of specifying the XY phase of the antennas. ... Unless you explicitly turn off solving for XY phase in gpcal , then the only important XY phase value is that for the reference antenna. ... means that gpcal will solve for the XY phase of the reference antenna. ... By default it solves for all XY phases, except for the reference antenna. ...

Proposal Identification No.: R2103 Date Received: 2005­May­30 04:59:22 Technical Page Proposal Type: Regular General Category: Planetary Radar Observation Category: Solar System Total Time Requested: 48 Hours Proposal Title: Surface Properties of Titan from Arecibo Radar Observations ABSTRACT: We are requesting S­band planetary radar time for twelve observations of Titan in January, 2006. ... Maybe Part of the observing run. ...

... Scientific goals . ... STUDY OF THE MARTIAN SURFACE COMPOSITION AND ITS PHYSICAL PROPERTIES . Main scientific objectives: . spectrophotometry of the planet in absorption bands of some rocks that may exist on the Martian surface in order to determine the surface composition; . study of the nature of aerosols by measuring spectral and angular distributions off brightness both above the planetary limb and of certain cloud-covered areas; . ... Main characteristics: . Spectral range . ...

. Next: Spectrum Up: R CORONAE BOREALIS STARS Previous: HISTORICAL BACKGROUND . Figure: The light curve of RCoronae Borealis during a fading event in 1859 . RCB stars were first identified by their characteristic light curves. A part of the light curve of RCrB itself, taken from over a century of observations compiled by Ludendorff (1906) is shown in Figure 1 . Spectrum . Galactic distribution and absolute magnitudes . Numbers and distances . Simon Jeffery . 2002-01-25

Next: CCD Operation Up: Charge Coupled Devices (CCDs) Previous: Charge Coupled Devices (CCDs) . ... However it is only now that a number of important X-ray astronomical applications of CCDs have reached critical development stages, so that this is an appropriate time to review the application of space-borne CCD instruments to cosmic X-ray astronomy, and highlight the particular concerns which are being addressed for X-ray instruments, as distinct from optical applications. ...

... It has been largely superceded by MatWeb . Conversion Factors . Material properties . Physical constants . Astronomical constants . This table gives conversion factors to convert various units to their SI equivalents. ... The units are SI. This is a short list of physical constants in SI units. ... Boltzmann constant . ... Gas constant . ... Mass . ... Plank's . ... Radiation constant . ... This is a short list of astronomical constants in SI units. ... Sun . ...