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... We will consider the rms, (K), for observations with a receiver of system temperature, T , frequency resolution, per polarization, and total integration time per observing cycle, . ... For ``in-band'' frequency switching, the line under investigation is always in the observing band. ... Position Switching or ``Out-of-Band'' Frequency Switching: Here the line is only observed for one half of the time, with noise being present all of the time. ...

... The following charts/text are intended as tools for monitoring the Type Ia supernovae ( SNe ) event visually or photographically (utilizing telescope equipped CCD equipment).The files include: A replication of The Type Ia SNe , V- magnitude (with data point checks from other cited references)and color index (B-V) templete (to indicate a general color-related trend of the type Ia ... I believe this might help alleviate some of the problems involving the making of acceptable amateur light curves...

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...

Follow-up astrometry and recoveries are made with the ANU 40 inch (1.0-m) f/8 reflector at Siding Spring Observatory (IAU code 413). ... A routine follow-up of 2003 WY153 on 2003 Dec 15 became much more than routine when a faint object with unusual motion vector was found close to the target asteroid. ... During routine astrometry with the 1.0-m to improve the orbit of the Apollo asteroid 2004 CB, the asteroid was found on March 30 to have a short tail! ... Siding Spring Survey Main Page . ...

... POINTS (Precision Optical INTerferometer in Space) measures the angle between two widely separated stars. The nominal bright-star measurement accuracy of 2 microarcsec is achieved in two minutes of observing two magnitude 8 stars. ... The wide separation between simultaneously observed stars makes POINTS a global astrometric instrument and provides three major advantages: (1) reference stars can be anywhere in a 6? by 360? band (5% of the sky). ...

Next: Summary of Imaging Strategies Up: Primary Beams and Mosaicing Previous: Mosaicing Observing Strategies . ... Splitting: As with conventional reduction, for calibration and imaging purposes, it is easiest in Miriad to split the data into datasets containing a `single source' and single frequency band. ... vis=mosaic.uv . ... Data Selection: With mosaic visibility datasets, the select=ra and select=dec selection sub-commands can be useful to extract or manipulate a subset of the visibility data. ...

... They are concerned with Attitude Control System of the spacecraft, satellite visibility from tracking stations, limits on the satellite autonomous operations during the orbit, and needs for auxiliary operations with the spacecraft. ... Among the operational constraints the most important one is the number of programmed slews per orbit, which determines the maximum number of radio sources to be observed during one orbit. ... System temperature (K) . ... Progress of the RadioAstron Project in Pictures...

... ALMA . ... ARC Staff at ESO . ... The European ALMA Regional Centre (ARC) provides the interface between the ALMA project and the European science community. ... Below you can read the latest Announcements from the European ARC Network.. ... The call for 1-mm Very Long Baseline Interferometry (VLBI) proposals to use phased ALMA at Band 6 in Cycle 4, in collaboration with the Event Horizon Telescope Consortium (EHTC), will be released to coincide with the ALMA Cycle 4 Call for Proposals in March 2016...

... With enough velocity, a spacecraft can break loose from the Earth's gravity and enter an orbit around the Sun, like that of a planet. If it then orbits the Sun with the same period as the Earth--one year--it may keep a fixed position relative to Earth. ... If the distance is just right--about 4 times the distance to the Moon or 1/100 the distance to the Sun--the spacecraft, too, will need just one year to go around the Sun, and will keep its position between the Sun and the Earth. ...

... Observing . ... Solar Observing . ... April 3 (SUN) - Solar Observing, Central Park , Manhattan . ... APRIL'S SKY . ... Lecture Series at the American Museum of Natural History The Amateur Astronomers Association is proud to present an astronomy lecture series from October through May each year for our members and the .. ... The€аAmateur Astronomers Association of New York€аwas organized in 1927 to promote the study of Astronomy, emphasizing its cultural and inspirational value. ...

... With enough velocity, a spacecraft can break loose from the Earth's gravity and enter an orbit around the Sun, like that of a planet. If it then orbits the Sun with the same period as the Earth--one year--it may keep a fixed position relative to Earth. ... If the distance is just right--about 4 times the distan