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| <tr><td width=20><td><b>SCAT(1)</b><td align=right><b>SCAT(1)</b> |
| <tr><td width=20><td colspan=2> |
| <br> |
| <p><font size=+1><b>NAME </b></font><br> |
| |
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| |
| scat – sky catalogue and Digitized Sky Survey<br> |
| |
| </table> |
| <p><font size=+1><b>SYNOPSIS </b></font><br> |
| |
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| |
| <tt><font size=+1>scat<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>DESCRIPTION </b></font><br> |
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| |
| <i>Scat</i> looks up items in catalogues of objects outside the solar |
| system and implements database-like manipulations on sets of such |
| objects. It also provides an interface to <a href="../man1/astro.html"><i>astro</i>(1)</a> to plot the |
| locations of solar system objects. Finally, it displays images |
| from the Space Telescope Science Institute’s Digitized Sky Survey, |
| keyed to the catalogues. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Items are read, one per line, from the standard input and looked |
| up in the catalogs. Input is case-insensitive. The result of the |
| lookup becomes the set of objects available to the database commands. |
| After each lookup or command, if more than two objects are in |
| the set, <i>scat</i> prints how many objects are in the set; |
| otherwise it prints the objects’ descriptions or cross-index listings |
| (suitable for input to <i>scat</i>). An item is in one of the following |
| formats:<br> |
| <tt><font size=+1>ngc1234<br> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Number 1234 in the New General Catalogue of Nonstellar Objects, |
| NGC2000.0. The output identifies the type (<tt><font size=+1>Gx</font></tt>=galaxy, <tt><font size=+1>Pl</font></tt>=planetary |
| nebula, <tt><font size=+1>OC</font></tt>=open cluster, <tt><font size=+1>Gb</font></tt>=globular cluster, <tt><font size=+1>Nb</font></tt>=bright nebula, |
| <tt><font size=+1>C+N</font></tt>=cluster associated with nebulosity, <tt><font size=+1>Ast</font></tt>=asterism, <tt><font size=+1>Kt</font></tt>=knot |
| or nebulous region in a galaxy, |
| <tt><font size=+1>***</font></tt>=triple star, <tt><font size=+1>D*</font></tt>=double star, <tt><font size=+1>?</font></tt>=uncertain, <tt><font size=+1>−</font></tt>=nonexistent, <tt><font size=+1>PD</font></tt>=plate |
| defect, and (blank)=unverified or unknown), its position in 2000.0 |
| coordinates, its size in minutes of arc, a brief description, |
| and popular names.<br> |
| |
| </table> |
| <tt><font size=+1>ic1234<br> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Like NGC references, but from the Index Catalog.<br> |
| |
| </table> |
| <tt><font size=+1>sao12345<br> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Number 12345 in the Smithsonian Astrophysical Star Catalogue. |
| Output identifies the visual and photographic magnitudes, 2000.0 |
| coordinates, proper motion, spectral type, multiplicity and variability |
| class, and HD number.<br> |
| |
| </table> |
| <tt><font size=+1>m4</font></tt> Catalog number 4 in Messier’s catalog. The output is the NGC |
| number.<br> |
| <tt><font size=+1>abell1701<br> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Catalog number 1701 in the Abell and Zwicky catalog of clusters |
| of galaxies. Output identifies the magnitude of the tenth brightest |
| member of the cluster, radius of the cluster in degrees, its distance |
| in megaparsecs, 2000.0 coordinates, galactic latitude and longitude, |
| magnitude range of the cluster (the |
| ‘distance group’), number of members (the ‘richness group’), population |
| per square degree, and popular names.<br> |
| |
| </table> |
| <tt><font size=+1>planetarynebula<br> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| The set of NGC objects of the specified type. The type may be |
| a compact NGC code or a full name, as above, with no blank.<br> |
| |
| </table> |
| <tt><font size=+1>"α umi"<br> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Names are provided in double quotes. Known names are the Greek |
| letter designations, proper names such as Betelgeuse, bright variable |
| stars, and some proper names of stars, NGC objects, and Abell |
| clusters. Greek letters may be spelled out, e.g. <tt><font size=+1>alpha</font></tt>. Constellation |
| names must be the three-letter |
| abbreviations. The output is the SAO number. For non-Greek names, |
| catalog numbers and names are listed for all objects with names |
| for which the given name is a prefix.<br> |
| |
| </table> |
| <tt><font size=+1>12h34m −16<br> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Coordinates in the sky are translated to the nearest ‘patch’, |
| approximately one square degree of sky. The output is the coordinates |
| identifying the patch, the constellations touching the patch, |
| and the Abell, NGC, and SAO objects in the patch. The program |
| prints sky positions in several formats corresponding to |
| different precisions; any output format is understood as input.<br> |
| |
| </table> |
| <tt><font size=+1>umi</font></tt> All the patches in the named constellation.<br> |
| <tt><font size=+1>mars</font></tt>The planets are identified by their names. The names <tt><font size=+1>shadow</font></tt> |
| and <tt><font size=+1>comet</font></tt> refer to the earth’s penumbra at lunar distance and |
| the comet installed in the current <a href="../man1/astro.html"><i>astro</i>(1)</a>. The output is the |
| planet’s name, right ascension and declination, azimuth and altitude, |
| and phase for the moon and sun, as shown by |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>astro</font></tt>. The positions are current at the start of <i>scat</i>’s execution; |
| see the <tt><font size=+1>astro</font></tt> command in the next section for more information. |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| |
| </table> |
| The commands are:<br> |
| <tt><font size=+1>add</font></tt> <i>item</i>Add the named item to the set.<br> |
| <tt><font size=+1>keep</font></tt> <i>class ...<br> |
| </i> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Flatten the set and cull it, keeping only the specified classes. |
| The classes may be specific NGC types, all stars (<tt><font size=+1>sao</font></tt>), all NGC |
| objects (<tt><font size=+1>ngc</font></tt>), all M objects (<tt><font size=+1>m</font></tt>), all Abell clusters (<tt><font size=+1>abell</font></tt>), |
| or a specified brightness range. Brightness ranges are specified |
| by a leading <tt><font size=+1>></font></tt> or <tt><font size=+1><</font></tt> followed by a magnitude. Remember |
| that brighter objects have lesser magnitudes.<br> |
| |
| </table> |
| |
| </table> |
| <tt><font size=+1>drop</font></tt> <i>class ...<br> |
| </i> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Complement to <tt><font size=+1>keep</font></tt>.<br> |
| |
| </table> |
| |
| </table> |
| <tt><font size=+1>flat</font></tt> Some items such as patches represents sets of items. <i>Flat</i> |
| flattens the set so <i>scat</i> holds all the information available for |
| the objects in the set.<br> |
| <tt><font size=+1>print</font></tt> Print the contents of the set. If the information seems meager, |
| try flattening the set.<br> |
| <tt><font size=+1>expand</font></tt> <i>n<br> |
| </i> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Flatten the set, expand the area of the sky covered by the set |
| to be <i>n</i> degrees wider, and collect all the objects in that area. |
| If <i>n</i> is zero, <i>expand</i> collects all objects in the patches that |
| cover the current set.<br> |
| |
| </table> |
| |
| </table> |
| <tt><font size=+1>astro</font></tt> <i>option<br> |
| </i> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Run <a href="../man1/astro.html"><i>astro</i>(1)</a> with the specified <i>options</i> (to which will be appended |
| <tt><font size=+1>−p</font></tt>), to discover the positions of the planets. <tt><font size=+1>Astro</font></tt>’s <tt><font size=+1>−d</font></tt> and |
| <tt><font size=+1>−l</font></tt> options can be used to set the time and place; by default, |
| it’s right now at the coordinates in <tt><font size=+1>/lib/sky/here</font></tt>. Running <tt><font size=+1>astro</font></tt> |
| does not change the positions of planets |
| already in the display set, so <tt><font size=+1>astro</font></tt> may be run multiple times, |
| executing e.g. <tt><font size=+1>add mars</font></tt> each time, to plot a series of planetary |
| positions.<br> |
| |
| </table> |
| |
| </table> |
| <tt><font size=+1>plot</font></tt> <i>option<br> |
| </i> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Expand and plot the set in a new window on the screen. Symbols |
| for NGC objects are as in Sky Atlas 2000.0, except that open clusters |
| are shown as stippled disks rather than circles. Abell clusters |
| are plotted as a triangle of ellipses. The planets are drawn as |
| disks of representative color with the first letter |
| of the name in the disk (lower case for inferior planets; upper |
| case for superior); the sun, moon, and earth’s shadow are unlabeled |
| disks. Objects larger than a few pixels are plotted to scale; |
| however, <i>scat</i> does not have the information necessary to show |
| the correct orientation for galaxies. |
| The option <tt><font size=+1>nogrid</font></tt> suppresses the lines of declination and right |
| ascension. By default, <i>scat</i> labels NGC objects, Abell clusters, |
| and bright stars; option <tt><font size=+1>nolabel</font></tt> suppresses these while <tt><font size=+1>alllabel</font></tt> |
| labels stars with their SAO number as well. The default size is |
| 512x512; options <tt><font size=+1>dx</font></tt> <i>n</i> and <tt><font size=+1>dy</font></tt> <i>n</i> set the <i>x</i> and |
| <i>y</i> extent. The option <tt><font size=+1>zenithup</font></tt> orients the map so it appears as |
| it would in the sky at the time and location used by the <tt><font size=+1>astro</font></tt> |
| command (<i>q.v.</i>).<br> |
| The output is designed to look best on an LCD display. CRTs have |
| trouble with the thin, grey lines and dim stars. The option <tt><font size=+1>nogrey</font></tt> |
| uses white instead of grey for these details, improving visibility |
| at the cost of legibility when plotting on CRTs.<br> |
| |
| </table> |
| |
| </table> |
| <tt><font size=+1>plate</font></tt> [[<i>ra dec</i>] <i>rasize</i> [<i>decsize</i>]]<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Display the section of the Digitized Sky Survey (plate scale approximately |
| 1.7 arcseconds per pixel) centered on the given right ascension |
| and declination or, if no position is specified, the current set |
| of objects. The maximum area that will be displayed is one degree |
| on a side. The horizontal and vertical sizes |
| may be specified in the usual notation for angles. If the second |
| size is omitted, a square region is displayed. If no size is specified, |
| the size is sufficient to display the centers of all the objects |
| in the current set. If a single object is in the set, the 500x500 |
| pixel block from the survey containing the center of |
| the object is displayed. The survey is stored in the CD-ROM juke |
| box; run <tt><font size=+1>9fs juke</font></tt> before running <i>scat</i>.<br> |
| |
| </table> |
| |
| </table> |
| <tt><font size=+1>gamma</font></tt> <i>value<br> |
| </i> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Set the gamma for converting plates to images. Default is –1.0. |
| Negative values display white stars, positive black. The images |
| look best on displays with depth 8 or greater. <i>Scat</i> does not change |
| the hardware color map, which should be set externally to a grey |
| scale; try the command <tt><font size=+1>getmap gamma</font></tt> (see |
| <i>getmap</i>(9.1)) on an 8-bit color-mapped display.<br> |
| |
| </table> |
| |
| </table> |
| |
| </table> |
| <p><font size=+1><b>EXAMPLES </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Plot the Messier objects and naked-eye stars in Orion.<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>ori<br> |
| keep m <6<br> |
| plot nogrid<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| |
| </table> |
| Draw a finder chart for Uranus:<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>uranus<br> |
| expand 5<br> |
| plot<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| |
| </table> |
| Show a partial lunar eclipse:<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>astro −d<br> |
| 2000 07 16 12 45<br> |
| moon<br> |
| add shadow<br> |
| expand 2<br> |
| plot<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| |
| </table> |
| Draw a map of the Pleiades.<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>"alcyone"<br> |
| expand 1<br> |
| plot<br> |
| </font></tt> |
| </table> |
| |
| </table> |
| <p><font size=+1><b>FILES </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>/usr/local/plan9/sky/*.scat<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>SOURCE </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>/usr/local/plan9/src/cmd/scat<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>SEE ALSO </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <a href="../man1/astro.html"><i>astro</i>(1)</a><br> |
| <tt><font size=+1>/usr/local/plan9/sky/constelnames </font></tt> the three-letter abbreviations |
| of the constellation names. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| The data was provided by the Astronomical Data Center at the NASA |
| Goddard Space Flight Center, except for NGC2000.0, which is Copyright |
| © 1988, Sky Publishing Corporation, used (but not distributed) |
| by permission. The Digitized Sky Survey, 102 CD-ROMs, is not distributed |
| with the system. |
| |
| </table> |
| |
| <td width=20> |
| <tr height=20><td> |
| </table> |
| <!-- TRAILER --> |
| <table border=0 cellpadding=0 cellspacing=0 width=100%> |
| <tr height=15><td width=10><td><td width=10> |
| <tr><td><td> |
| <center> |
| <a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a> |
| </center> |
| </table> |
| <!-- TRAILER --> |
| </body></html> |
