Astronomy Picture of the Day . ... 6.02.2010 . ... Their two luminous trails are faintly paralleled by trails of background stars. But easier to pick out are the short, bright airplane trails converging toward the horizon and the Hong Kong International Airport that seem to offer a frenzied imitation of the celestial tracks . ... February 2010 . ... NASA Web Site Statements, Warnings, and Disclaimers . ... Publications with keywords: night sky . Publications with words: night sky . ...

Next: Combining Bias Frames Up: Preparing Your Calibration Previous: Input and Output . Except for summing the frames together, combining frames may require correcting for variations between the frames due to differing exposure times, sky background, extinctions, and positions. ... The input frames are combined by applying a sigma clipping algorithm at each pixel. ... The input frames are combined with a variant of the sigma clipping algorithm which works well with only a few frames. ...

... 2008 January 2 . A Galaxy is not a Comet . ... Explanation: This gorgeous galaxy and comet portrait was recorded on December 30th, in the skies over Hoogeveen, The Netherlands. The combined series of 60 x 60 second exposures finds the lovely green coma of Comet 8P/Tuttle near its predicted conjunction with the Triangulum Galaxy . Aligning each exposure with the stars shows the comet as a streak, slowly moving against the background stars and galaxy. ... About APOD | ...

XMM-Newton Science Analysis System Page: 1 rgscombine June 28, 2006 Abstract Combines a list of spectrum les to create one combined spectrum le, and the corresponding list of response matrices and background spectrum, to create one nal response matrix and background spectrum le, for a paticular RGS instrument and spectral order. ... A list of response matrix les, as produced by rgsrmfgen or rgsproc. A list of background spectrum les as produced by rgsspectrum or rgsproc for TOTAL spectra. ...

... They include: 4 dither patterns, 4 chop patterns, and 3 dither-chop patterns. For each of these, the observer will be able to specify, during the Phase II Proposal submission, the total number of positions desired (2 to 40), the dither size (0 to 40 arcsecs), the chop size (0 to 1800 arcsecs), and the orientation of the pattern on the sky. ... In addition, the figure number where the pattern is graphically shown is given in column 5 of Table 10.1 . ... Figure 10.3 . ... 0.0 - 1800.0 . ...

... ESO is building what will be the World's largest optical telescope array, The Very Large Telescope (VLT). The VLT Project organisation is responsible for the design and construction of the Unit Telescopes, including enclosures, optics, adapter-rotators and coating unit. ... Unit Telescopes Overview - This page is outdated, an update is in process. ... Secondary mirror (M2 Unit) - This page is outdated, an update is in process. ... Coating Unit - This page is outdated, an update is in process. ...

... This paper describes the main algorithms used by the Einstein Level One processing to create the exposure masks and the background maps for Einstein IPC images, and how these algorithms were recreated in the IRAF environment. Our goal was to recreate the algorithms used by the Level One Processing to create exposure masks and background maps for Einstein Image Proportional Counter (IPC) data (cf. sections 2.5 and 2.7 of Harnden et al. ...

Next: *imcalc* - Obtain a Up: Calibration Previous: Exposure Map . Background maps are provided by the standard processing for all ROSAT and Einstein instruments. For the PSPC and IPC these are in three standard bands: soft, hard, and broad (Table 6.2). ... N.B.: ROSAT PSPC background maps in SASS 5-6 or higher are generated by smoothing a source-subtracted, exposure corrected image (see the ROSAT Data Products Guide). ... imcalc* - Obtain a background subtracted image for ROSAT PSPC Data . ...

Next: The STScI NICMOS Calibration Up: No Title Previous: CONICA: The high resolution . The STScI NICMOS Calibration Pipeline . Introduction . ... Dark Current Subtraction . ... Input Data . ... Scalar Background Subtraction . 2-D Background Subtraction . ... Status and Goals of the NICMOS Calibration Plan . ... Photometry . ... Photometric Performance of NICMOS . ... NICMOS Photometry. ... ST-ECF Grism Spectrum Software for NICMOS Grism Data . ... Analysis . ... STScI NICMOS Software . ...

... The sband transmitter measures reflected power using directional couplers at: . ... waveguide along rotary floor out to turnstile, horn . ... horn . ... Any water in this piece of waveguide would flow away from the antenna reflected power coupler that is next to the horn . ... We can see a changed in the reflected power as we go from high to low za (if water in the waveguide) using the network analyzer. the null at 25 feet is probably the distance from the turnstile to just beyond the rotary coupler...

Next: Extragalactic Gravitational Wave Background Previous: Transparency of the Stochastic . Let the sky be observed with a detector having a pencil beam diagram across. The number of stars per frequency decade that is swept by the detector is a function of celestial coordinates (say, galactic coordinates l , b ): . ... It is clear from the figure that for an all-sky detector the Galaxy becomes transparent above the frequency  Hz. ...

OptInt PmWiki : Pm Wiki / Wiki Style Examples . Wiki styles | ... PmWiki uses WikiStyles for styling text with color and other attributes. PmWiki 2.0 introduced the ability to control the styling further and to even place styles on blocks. ... In addition, an author can define a style "shortcut" by using the define= property. For example, to define a style of %red% , one can use: . define=mystyle color=red% Here is some %mystyle% red text created using a style shortcut. ...