... The measurements themselves should be stored in a column with the label SIGNAL. ... Programs will expect that SIGNAL represents the integration of the photon flux for the exposure time given in the EXPTIME column (see section ). ... In that case, the column label should be RAWMAG; see Table . Programs will expect RAWMAG to be the usual negative logarithms of intensities; that is, RAWMAG values only use EXPTIME in determining weights. ...

Target Acquisition Reference Information . Figure 7.1 on page 88 shows mean predicted count rates as a function of (B - V) 0 color for the four acquisition mirrors. Also shown are the fits to the predicted count rates for different amounts of reddening. ... You can estimate target acquisition count rates using the plots instead of Table 7.1 on page 92 : . ... Read from the Figures (depending on the mirror used) the predicted count rate. ...

CORONAL METALLICITIES OF ACTIVE BINARIES Vinay Kashyap, Jeremy Drake, Deron Pease Harvard­Smithsonian Center for Astrophysics JЁ urgen Schmitt Max Planck Institut fЁ ur Extraterrestriche Physik SUMMARY We analyze EUV and X­ray data on a sample of X­ray active binary stars (HR 1099, – And, UX Ari, VY Ari, ё UMa, 44i Boo, and YY Gem) to determine coronal abundances. EUVE spectrometer data are used to obtain line fluxes, which are then used to determine Differential Emission Measures (DEMs). ...

... In combining the data, it is assumed that the low resolution image better represents the short spacing data, whereas the high resolution best represents the fine structure. ... Key: out The output image. ... Key: factor The flux calibration factor. ... In practise, the calibration may not be perfect, and an extra calibration factor will be required to align the flux scales. "factor" gives the factor to scale the low resolution image to put it on the same flux scale as the high resolution image. ...

The azimuth encoder rack gear is mounted on the inside of the azimuth ring girder. The azimuth encoder turns on this gear as the azimuth moves 0 to 720 degrees. ... The software assumes that this arc length along the encoder rack gear is correct (at a constant radius of 127/2 feet). The error in the radius of the rack gear becomes an azimuth error. To measure the error in the azimuth encoder rack gear, jon hagen built a proximity sensor. ... To compute the az encoder runout error: . ...

... Next: The PROS Big Up: Software Systems Previous: Data Reduction Software . ... The srcinten task provides PROS users with a tool to compute count rates for point sources in the ROSAT High Resolution Imager (HRI). ... Corrected upper limits are cited at locations where the count rate falls below the source detection threshold. ... Srcinten is a new PROS task that computes and applies the above correction factors to the net counts in a user-specified aperture. ...

... The task lccorr takes, as its input, source and (optionally) local-background timeseries (TS) created by evselect , in which the time variation of the flux is represented by counts within time bins of equal duration. The main task of lccorr is to correct these time series for losses in flux due to a number of causes (exposure correction); these corrections are described in subsections 3.3 and 3.4 . ... Exposure corrections - introduction: . ... Correction of non-point-source time series: . ...

... Unsafe act - a behavioral departure from an accepted, normal, or correct procedure or practice which, in the past, has produced injury or property damage or which has potential for doing so in the future; an unnecessary exposure to a hazard; conduct reducing the degree or safety normally present in an activity. ... Any hazardous unsafe condition, or act that presents a situation of imminent danger to life and/or property requires urgent action. ...

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... A hundred years later, a handful of Tunguska-sized asteroids have been spotted by telescopes, but most remain unseen. The asteroid designated 2008 TC3 , which made the news on October 6th before colliding with the Earth on October 7th was too small to constitute a part of the "Earth impact hazard". ... 2008 TC3, for example, finally exploded in the atmosphere above Sudan . ... Wednesday, 8 October 2008 01:15 . International Year of Astronomy, Ireland National Node . ...

... The colors indicate the relative motions of galaxies with accurately measured distances, with shades of green and blue indicating motions toward us and shades of yellow to red indicating motions away from us. Our nearest neighbors have only small relative motions (represented by yellows and greens), as seen best in the exploded view of the right panel. We, along with all these nearest neighbors, are moving together toward the lower right corner of the figures. ...