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8<tr><td width=20><td>
9<tr><td width=20><td><b>SCAT(1)</b><td align=right><b>SCAT(1)</b>
10<tr><td width=20><td colspan=2>
11 <br>
12<p><font size=+1><b>NAME </b></font><br>
13
14<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
15
16 scat &ndash; sky catalogue and Digitized Sky Survey<br>
17
18</table>
19<p><font size=+1><b>SYNOPSIS </b></font><br>
20
21<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
22
23 <tt><font size=+1>scat<br>
24 </font></tt>
25</table>
26<p><font size=+1><b>DESCRIPTION </b></font><br>
27
28<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
29
30 <i>Scat</i> looks up items in catalogues of objects outside the solar
31 system and implements database-like manipulations on sets of such
32 objects. It also provides an interface to <a href="../man1/astro.html"><i>astro</i>(1)</a> to plot the
33 locations of solar system objects. Finally, it displays images
34 from the Space Telescope Science Institute&#8217;s Digitized Sky Survey,
35 keyed to the catalogues.
36 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
37
38 Items are read, one per line, from the standard input and looked
39 up in the catalogs. Input is case-insensitive. The result of the
40 lookup becomes the set of objects available to the database commands.
41 After each lookup or command, if more than two objects are in
42 the set, <i>scat</i> prints how many objects are in the set;
43 otherwise it prints the objects&#8217; descriptions or cross-index listings
44 (suitable for input to <i>scat</i>). An item is in one of the following
45 formats:<br>
46 <tt><font size=+1>ngc1234<br>
47 </font></tt>
48 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
49
50 Number 1234 in the New General Catalogue of Nonstellar Objects,
51 NGC2000.0. The output identifies the type (<tt><font size=+1>Gx</font></tt>=galaxy, <tt><font size=+1>Pl</font></tt>=planetary
52 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,
53 <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
54 or nebulous region in a galaxy,
55 <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>&#8722;</font></tt>=nonexistent, <tt><font size=+1>PD</font></tt>=plate
56 defect, and (blank)=unverified or unknown), its position in 2000.0
57 coordinates, its size in minutes of arc, a brief description,
58 and popular names.<br>
59
60 </table>
61 <tt><font size=+1>ic1234<br>
62 </font></tt>
63 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
64
65 Like NGC references, but from the Index Catalog.<br>
66
67 </table>
68 <tt><font size=+1>sao12345<br>
69 </font></tt>
70 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
71
72 Number 12345 in the Smithsonian Astrophysical Star Catalogue.
73 Output identifies the visual and photographic magnitudes, 2000.0
74 coordinates, proper motion, spectral type, multiplicity and variability
75 class, and HD number.<br>
76
77 </table>
78 <tt><font size=+1>m4</font></tt>&nbsp;&nbsp;&nbsp;&nbsp;Catalog number 4 in Messier&#8217;s catalog. The output is the NGC
79 number.<br>
80 <tt><font size=+1>abell1701<br>
81 </font></tt>
82 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
83
84 Catalog number 1701 in the Abell and Zwicky catalog of clusters
85 of galaxies. Output identifies the magnitude of the tenth brightest
86 member of the cluster, radius of the cluster in degrees, its distance
87 in megaparsecs, 2000.0 coordinates, galactic latitude and longitude,
88 magnitude range of the cluster (the
89 &#8216;distance group&#8217;), number of members (the &#8216;richness group&#8217;), population
90 per square degree, and popular names.<br>
91
92 </table>
93 <tt><font size=+1>planetarynebula<br>
94 </font></tt>
95 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
96
97 The set of NGC objects of the specified type. The type may be
98 a compact NGC code or a full name, as above, with no blank.<br>
99
100 </table>
101 <tt><font size=+1>&quot;&#945; umi&quot;<br>
102 </font></tt>
103 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
104
105 Names are provided in double quotes. Known names are the Greek
106 letter designations, proper names such as Betelgeuse, bright variable
107 stars, and some proper names of stars, NGC objects, and Abell
108 clusters. Greek letters may be spelled out, e.g. <tt><font size=+1>alpha</font></tt>. Constellation
109 names must be the three-letter
110 abbreviations. The output is the SAO number. For non-Greek names,
111 catalog numbers and names are listed for all objects with names
112 for which the given name is a prefix.<br>
113
114 </table>
115 <tt><font size=+1>12h34m &#8722;16<br>
116 </font></tt>
117 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
118
119 Coordinates in the sky are translated to the nearest &#8216;patch&#8217;,
120 approximately one square degree of sky. The output is the coordinates
121 identifying the patch, the constellations touching the patch,
122 and the Abell, NGC, and SAO objects in the patch. The program
123 prints sky positions in several formats corresponding to
124 different precisions; any output format is understood as input.<br>
125
126 </table>
127 <tt><font size=+1>umi</font></tt>&nbsp;&nbsp;&nbsp;All the patches in the named constellation.<br>
128 <tt><font size=+1>mars</font></tt>The planets are identified by their names. The names <tt><font size=+1>shadow</font></tt>
129 and <tt><font size=+1>comet</font></tt> refer to the earth&#8217;s penumbra at lunar distance and
130 the comet installed in the current <a href="../man1/astro.html"><i>astro</i>(1)</a>. The output is the
131 planet&#8217;s name, right ascension and declination, azimuth and altitude,
132 and phase for the moon and sun, as shown by
133
134 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
135
136 <tt><font size=+1>astro</font></tt>. The positions are current at the start of <i>scat</i>&#8217;s execution;
137 see the <tt><font size=+1>astro</font></tt> command in the next section for more information.
138
139 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
140
141
142 </table>
143 The commands are:<br>
144 <tt><font size=+1>add</font></tt> <i>item</i>Add the named item to the set.<br>
145 <tt><font size=+1>keep</font></tt> <i>class ...<br>
146 </i>
147 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
148
149
150 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
151
152 Flatten the set and cull it, keeping only the specified classes.
153 The classes may be specific NGC types, all stars (<tt><font size=+1>sao</font></tt>), all NGC
154 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>),
155 or a specified brightness range. Brightness ranges are specified
156 by a leading <tt><font size=+1>&gt;</font></tt> or <tt><font size=+1>&lt;</font></tt> followed by a magnitude. Remember
157 that brighter objects have lesser magnitudes.<br>
158
159 </table>
160
161 </table>
162 <tt><font size=+1>drop</font></tt> <i>class ...<br>
163 </i>
164 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
165
166
167 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
168
169 Complement to <tt><font size=+1>keep</font></tt>.<br>
170
171 </table>
172
173 </table>
174 <tt><font size=+1>flat</font></tt>&nbsp;&nbsp;&nbsp;&nbsp;Some items such as patches represents sets of items. <i>Flat</i>
175 flattens the set so <i>scat</i> holds all the information available for
176 the objects in the set.<br>
177 <tt><font size=+1>print</font></tt>&nbsp;&nbsp;&nbsp;Print the contents of the set. If the information seems meager,
178 try flattening the set.<br>
179 <tt><font size=+1>expand</font></tt> <i>n<br>
180 </i>
181 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
182
183
184 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
185
186 Flatten the set, expand the area of the sky covered by the set
187 to be <i>n</i> degrees wider, and collect all the objects in that area.
188 If <i>n</i> is zero, <i>expand</i> collects all objects in the patches that
189 cover the current set.<br>
190
191 </table>
192
193 </table>
194 <tt><font size=+1>astro</font></tt> <i>option<br>
195 </i>
196 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
197
198
199 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
200
201 Run <a href="../man1/astro.html"><i>astro</i>(1)</a> with the specified <i>options</i> (to which will be appended
202 <tt><font size=+1>&#8722;p</font></tt>), to discover the positions of the planets. <tt><font size=+1>Astro</font></tt>&#8217;s <tt><font size=+1>&#8722;d</font></tt> and
203 <tt><font size=+1>&#8722;l</font></tt> options can be used to set the time and place; by default,
204 it&#8217;s right now at the coordinates in <tt><font size=+1>/lib/sky/here</font></tt>. Running <tt><font size=+1>astro</font></tt>
205 does not change the positions of planets
206 already in the display set, so <tt><font size=+1>astro</font></tt> may be run multiple times,
207 executing e.g. <tt><font size=+1>add mars</font></tt> each time, to plot a series of planetary
208 positions.<br>
209
210 </table>
211
212 </table>
213 <tt><font size=+1>plot</font></tt> <i>option<br>
214 </i>
215 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
216
217
218 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
219
220 Expand and plot the set in a new window on the screen. Symbols
221 for NGC objects are as in Sky Atlas 2000.0, except that open clusters
222 are shown as stippled disks rather than circles. Abell clusters
223 are plotted as a triangle of ellipses. The planets are drawn as
224 disks of representative color with the first letter
225 of the name in the disk (lower case for inferior planets; upper
226 case for superior); the sun, moon, and earth&#8217;s shadow are unlabeled
227 disks. Objects larger than a few pixels are plotted to scale;
228 however, <i>scat</i> does not have the information necessary to show
229 the correct orientation for galaxies.
230 The option <tt><font size=+1>nogrid</font></tt> suppresses the lines of declination and right
231 ascension. By default, <i>scat</i> labels NGC objects, Abell clusters,
232 and bright stars; option <tt><font size=+1>nolabel</font></tt> suppresses these while <tt><font size=+1>alllabel</font></tt>
233 labels stars with their SAO number as well. The default size is
234 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
235 <i>y</i> extent. The option <tt><font size=+1>zenithup</font></tt> orients the map so it appears as
236 it would in the sky at the time and location used by the <tt><font size=+1>astro</font></tt>
237 command (<i>q.v.</i>).<br>
238 The output is designed to look best on an LCD display. CRTs have
239 trouble with the thin, grey lines and dim stars. The option <tt><font size=+1>nogrey</font></tt>
240 uses white instead of grey for these details, improving visibility
241 at the cost of legibility when plotting on CRTs.<br>
242
243 </table>
244
245 </table>
246 <tt><font size=+1>plate</font></tt> [[<i>ra dec</i>] <i>rasize</i> [<i>decsize</i>]]<br>
247
248 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
249
250
251 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
252
253 Display the section of the Digitized Sky Survey (plate scale approximately
254 1.7 arcseconds per pixel) centered on the given right ascension
255 and declination or, if no position is specified, the current set
256 of objects. The maximum area that will be displayed is one degree
257 on a side. The horizontal and vertical sizes
258 may be specified in the usual notation for angles. If the second
259 size is omitted, a square region is displayed. If no size is specified,
260 the size is sufficient to display the centers of all the objects
261 in the current set. If a single object is in the set, the 500x500
262 pixel block from the survey containing the center of
263 the object is displayed. The survey is stored in the CD-ROM juke
264 box; run <tt><font size=+1>9fs juke</font></tt> before running <i>scat</i>.<br>
265
266 </table>
267
268 </table>
269 <tt><font size=+1>gamma</font></tt> <i>value<br>
270 </i>
271 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
272
273
274 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
275
276 Set the gamma for converting plates to images. Default is &ndash;1.0.
277 Negative values display white stars, positive black. The images
278 look best on displays with depth 8 or greater. <i>Scat</i> does not change
279 the hardware color map, which should be set externally to a grey
280 scale; try the command <tt><font size=+1>getmap gamma</font></tt> (see
281 <i>getmap</i>(9.1)) on an 8-bit color-mapped display.<br>
282
283 </table>
284
285 </table>
286
287</table>
288<p><font size=+1><b>EXAMPLES </b></font><br>
289
290<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
291
292 Plot the Messier objects and naked-eye stars in Orion.<br>
293
294 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
295
296 <tt><font size=+1>ori<br>
297 keep m &lt;6<br>
298 plot nogrid<br>
299
300 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
301 </font></tt>
302
303 </table>
304 Draw a finder chart for Uranus:<br>
305
306 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
307
308 <tt><font size=+1>uranus<br>
309 expand 5<br>
310 plot<br>
311
312 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
313 </font></tt>
314
315 </table>
316 Show a partial lunar eclipse:<br>
317
318 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
319
320 <tt><font size=+1>astro &#8722;d<br>
321 2000 07 16 12 45<br>
322 moon<br>
323 add shadow<br>
324 expand 2<br>
325 plot<br>
326
327 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
328 </font></tt>
329
330 </table>
331 Draw a map of the Pleiades.<br>
332
333 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
334
335 <tt><font size=+1>&quot;alcyone&quot;<br>
336 expand 1<br>
337 plot<br>
338 </font></tt>
339 </table>
340
341</table>
342<p><font size=+1><b>FILES </b></font><br>
343
344<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
345
346 <tt><font size=+1>/usr/local/plan9/sky/*.scat<br>
347 </font></tt>
348</table>
349<p><font size=+1><b>SOURCE </b></font><br>
350
351<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
352
353 <tt><font size=+1>/usr/local/plan9/src/cmd/scat<br>
354 </font></tt>
355</table>
356<p><font size=+1><b>SEE ALSO </b></font><br>
357
358<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
359
360 <a href="../man1/astro.html"><i>astro</i>(1)</a><br>
361 <tt><font size=+1>/usr/local/plan9/sky/constelnames </font></tt> the three-letter abbreviations
362 of the constellation names.
363 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
364
365 The data was provided by the Astronomical Data Center at the NASA
366 Goddard Space Flight Center, except for NGC2000.0, which is Copyright
367 &copy; 1988, Sky Publishing Corporation, used (but not distributed)
368 by permission. The Digitized Sky Survey, 102 CD-ROMs, is not distributed
369 with the system.
370
371</table>
372
373<td width=20>
374<tr height=20><td>
375</table>
376<!-- TRAILER -->
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