... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

Next: A box, to include Up: To produce a region Previous: To produce a region . select cursor and circle . When in the image window, the mouse now has a box shape with an arrow at the upper left corner. The mouse buttons act as follows: . LEFT - to move the center of the circle at the position of the arrow point. ... RIGHT - idle. center the circle at the point source by positioning the arrow point and clicking on the LEFT mouse button. A circle will appear at the arrow position. ...

... 5.4.1 Flat Fielding . ... Consequently, there are two distinct flat-field reference images that must be applied during calibration of coronagraphic science images. ... Observers should examine the flat fields used to calibrate their data to determine whether any features in their science images are caused by these local flat-field errors. The second reference flat is a spot flat field ( header keyword CFLTFILE , cfl.fits ) which contains the vignetted shadows of the occulting spots. ...

Set the dimensions of the drawing area. ... Allow the drawing area to be resized to fit the main xmgr window (no scrollbars will appear). ... Set the drawing area dimensions to landscape, generally this will be larger than the window allocated for xmgr, and scroll bars will appear. ... Set the drawing area dimensions to portrait, generally this will be larger than the window allocated for xmgr, and scroll bars will appear. ...

... The general-purpose data reduction package FIGARO is now available to be run from the IRAF CL, and more Starlink applications will follow in due course. ... A system has been developed to enable packages written for the Starlink Software Environment to be run from the IRAF CL so that an IRAF user can mix and match application tasks from the two environments as required to process data, all under the control of the IRAF CL. ... Mixing IRAF and Starlink Applications ­ FIGARO under IRAF 3. ...

... Version 1.7.4 was rejected. ... Some improvements to documentation - Now depends on statistics-0.16 Version 0.25 2000-07-18 (MT) -------------- - improved documentation - dsls implemented , which listed the files in the given directory, indicating which ones are datasets, and which are unrecognised. - dsaddcomment implemented , which adds a comment record to the given attributable object. - dsaddhistory implemented , which adds a history record to the given attributable object. - dssetlabel ...

... The Flux Calibration window contains the options required for the atmospheric extinction and flux calibration. Click the button in the Main window to pop up the Flux Calibration window. The button corrects the spectra for extinction and requires that the field Extinction table: contains a valid extinction table name. ... After clicking a file selection window appears requesting the name of the standard star image, which must be a one dimensional reduced, extinction corrected spectrum. ...

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... Character level elements are used to specify either the structural meaning or the physical appearence of marked text without causing a paragraph break. ... Highlighting elements are allowed within the content of other highlighting elements, but implementations are not required to render these nested highlighting elements distinctly from non-nested elements. ... An SGML identifier used as the target for hypertext links or for naming particular elements in associated style sheets. ... CLASS . ...

... Our Solar System has the most planets of any known star, most probably because it is so hard to detect planets around other stars. ... Galaxy Cluster Abell 1689 Magnifies the Dark Universe . ... NGC 1365: Majestic Island Universe . ... Barred spiral galaxy NGC 1365 is truly a majestic island universe some 200,000 light-years across. Located a mere 60 million light-years away toward the chemical constellation Fornax, NGC 1365 is a dominant member of the well-studied Fornax galaxy cluster. ... 200 | ...

The First Law (1): Energy is Conserved in a closed system: . ... We usually consider work and heat flow as the two kinds of energy . The Second Law (2): The Law of Entropy: . ... The amount of disorder increases . ... You can not go from a disordered system to an ordered system without inputting more energy (this is the most important attribute of the second law) . ... In no way can we recover work of that this disordered system without putting energy into the system. ... More on Thermodynamics . ...

This module provides for user authentication using text files. ... Available after Apache 1.3.20] The supplied username and password must be in the AuthUserFile database, and the username must also match the system's name for the owner of the file being requested. ... Available after Apache 1.3.20] The supplied username and password must be in the AuthUserFile database, the name of the group that owns the file must be in the AuthGroupFile database, and the username must be a member of that group. ...

... Miriad is useful for cube mosaicing. ... coverage.pl -c cube_number [-m scan_letters ] where cube_number is the standard HIPASS cube number . ... On attila (Epping), the following example will extract all scans for cube H014 from all slots in the cdrom changer: coverage.pl -c 14 -r '/cdrom/cdrom[2-7]' -w /DATA/MULTI_1/mscal -x sdfits -y mscal -a 0 Use the command cd_mountall on attila to mount the cdrom changer (cdroms label down), and cd_umountall to dismount the cdrom changer. ...

Note added 3 June 2003 to . ... Furthermore, (iii) its orbital plane gave the satellite at apogee a velocity tangential to the ecliptic, helping it stay in the plasma sheet, rather than cut across it. ... Figure #1 Point A in this drawing is perigee (just above Kourou), B is apogee , the solid line perpendicular to the Earth axis is a cut through the equatorial plane, and its continuation parallel to the ecliptic represents a cut through the plasma sheet (not to scale). ...

... The general­purpose data reduction package FIGARO is now available to be run from the IRAF CL, and more Starlink applications will follow in due course. ... A system has been developed to enable packages written for the Starlink Software Environment to be run from the IRAF CL so that an IRAF user can mix and match application tasks from the two environments as required to process data, all under the control of the IRAF CL. ... Mixing IRAF and Starlink Applications -- FIGARO under IRAF 179 3. ...

... SGML . The text/html content type . In this section, we begin the specification of HTML 4.0, starting with the contract between authors, documents, users, and user agents. ... These recommendations are not normative and conformance with this specification does not depend on their realization. ... An HTML document is an SGML document that meets the constraints of this specification. ... A user is a person who interacts with a user agent to view, hear, or otherwise use a rendered HTML document. ...

GALFA Meeting, Arecibo, March 21-23 2003 . The GALFA Consortium requests that NAIC immediately commence development of a prototype spectroscopic system for Galactic astronomy using ALFA. ... The ALFA Consortium proposes that NAIC initiate a program to develop a prototype test-bed system for assessing how well this design approach could satisfy the need for (1) a HI spectrometer for GALFA, and (2) serve as a building block of a RLL GALFA spectrometer. ...

... Thus the FTE described below must be added to the AOF FTE budget. ... Activity Scientist overview of changes (R7M) Observing preparation tool ( section 15.1) Instrument Control Panel ( section 15.2) Modification of AOF / Hawk-I acquisition template ( section 15.3) Site quality monitoring and display ( section 15.5) Exposure Time Calculator ( section 15.6) Modification Observing Tool (OT3) ( section 15.8) TOTAL FTE effort 1 0.1 0.3 0.3 0.3 0.2 0.3 2.5 ...

... FIELD | ... METHOD . ... static int . ... Set this flag to have the ImageProcessor that is passed to the run() method converted to a FloatProcessor. static int . ... Set this flag if the filter wants its run() method to be called for all the slices in a stack. static int . ... Set this flag if the filter does not want its run method called. static int . ... Set this flag if the setup method of the filter should be called again after the calls to the run(ip) have finished. static int . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2006 January 10 . The Phases of Venus . ... Explanation: Venus goes through phases. ... The above time-lapse sequence , however, was taken over the course of many months and shows not only how Venus changes phase but how it's apparent angular size also changes. ... About APOD | ... NASA Web Site Statements, Warnings, and Disclaimers . ...