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diff --git a/man/man1/scat.1 b/man/man1/scat.1 new file mode 100644 index 00000000..d9bf8db8 --- /dev/null +++ b/man/man1/scat.1 @@ -0,0 +1,335 @@ +.TH SCAT 7 +.SH NAME +scat \- sky catalogue and Digitized Sky Survey +.SH SYNOPSIS +.B scat +.SH DESCRIPTION +.I Scat +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 +.IR astro (7) +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. +.PP +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 +prints how many objects are in the set; otherwise it +prints the objects' +descriptions or cross-index listings (suitable for input to +.IR scat ). +An item is in one of the following formats: +.TP +.B ngc1234 +Number 1234 in the New General Catalogue of +Nonstellar Objects, NGC2000.0. +The output identifies the type +.RB( Gx =galaxy, +.BR Pl =planetary +nebula, +.BR OC =open +cluster, +.BR Gb =globular +cluster, +.BR Nb =bright +nebula, +.BR C+N =cluster +associated with nebulosity, +.BR Ast =asterism, +.BR Kt =knot +or nebulous region in a galaxy, +.BR *** =triple +star, +.BR D* =double +star, +.BR ? =uncertain, +.BR - =nonexistent, +.BR PD =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. +.TP +.B ic1234 +Like NGC references, but from the Index Catalog. +.TP +.B sao12345 +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. +.TP +.B m4 +Catalog number 4 in Messier's catalog. +The output is the NGC number. +.TP +.B abell1701 +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. +.TP +.B planetarynebula +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. +.TP +\fL"α umi"\fP +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. +.BR alpha . +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. +.TP +.B 12h34m -16 +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. +.TP +.B umi +All the patches in the named constellation. +.TP +.B mars +The planets are identified by their names. +The names +.B shadow +and +.B comet +refer to the earth's penumbra at lunar distance and the comet installed in the current +.IR astro (7). +The output is the planet's name, right ascension and declination, azimuth and altitude, and phase +for the moon and sun, as shown by +.BR astro . +The positions are current at the start of +.I scat 's +execution; see the +.B astro +command in the next section for more information. +.PP +The commands are: +.TF print +.TP +.BI add " item" +Add the named item to the set. +.TP +.BI keep " class ..." +Flatten the set and cull it, keeping only the specified classes. +The classes may be specific NGC types, +all stars +.RB ( sao ), +all NGC objects +.RB ( ngc ), +all M objects +.RB ( m ), +all Abell clusters +.RB ( abell ), +or a specified brightness range. +Brightness ranges are specified by a leading +.B > +or +.B < +followed by a magnitude. +Remember that brighter objects have lesser magnitudes. +.TP +.BI drop " class ..." +Complement to +.BR keep . +.TP +.BI flat +Some items such as patches represents sets of items. +.I Flat +flattens the set so +.I scat +holds all the information available for the objects in the set. +.TP +.BI print +Print the contents of the set. If the information seems meager, try +flattening the set. +.TP +.BI expand " n" +Flatten the set, +expand the area of the sky covered by the set to be +.I n +degrees wider, and collect all the objects in that area. +If +.I n +is zero, +.I expand +collects all objects in the patches that cover the current set. +.TP +.BI astro " option" +Run +.IR astro (7) +with the specified +.I options +(to which will be appended +.BR -p ), +to discover the positions of the planets. +.BR Astro 's +.B -d +and +.B -l +options can be used to set the time and place; by default, it's right now at the coordinates in +.BR /lib/sky/here . +Running +.B astro +does not change the positions of planets already in the display set, +so +.B astro +may be run multiple times, executing e.g. +.B "add mars" +each time, to plot a series of planetary positions. +.TP +.BI plot " option" +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 +does not have the information necessary to show the correct orientation for galaxies. +.IP +The option +.B nogrid +suppresses the lines of declination and right ascension. +By default, +.I scat +labels NGC objects, Abell clusters, and bright stars; option +.B nolabel +suppresses these while +.B alllabel +labels stars with their SAO number as well. +The default size is 512×512; options +.B dx +.I n +and +.BR dy +.I n +set the +.I x +and +.I y +extent. +The option +.B zenithup +orients the map so it appears as it would in the sky at the time and +location used by the +.B astro +command +.RI ( q.v. ). +.IP +The output is designed to look best on an LCD display. +CRTs have trouble with the thin, grey lines and dim stars. +The option +.B nogrey +uses white instead of grey for these details, improving visibility +at the cost of legibility when plotting on CRTs. +.TP +.B "plate \f1[[\f2ra dec\f1] \f2rasize\f1 [\f2decsize\f1]]" +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 +500×500 pixel block from the survey containing the center +of the object is displayed. +The survey is stored in the CD-ROM juke box; run +.B 9fs +.B juke +before running +.IR scat . +.TP +.BI gamma " value" +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 +does not change the hardware color map, which +should be set externally to a grey scale; try the command +.B getmap gamma +(see +.IR getmap (9.1)) +on an 8-bit color-mapped display. +.PD +.SH EXAMPLES +Plot the Messier objects and naked-eye stars in Orion. +.EX + ori + keep m <6 + plot nogrid +.EE +.PP +Draw a finder chart for Uranus: +.EX + uranus + expand 5 + plot +.EE +.PP +Show a partial lunar eclipse: +.EX + astro -d + 2000 07 16 12 45 + moon + add shadow + expand 2 + plot +.EE +.PP +Draw a map of the Pleiades. +.EX + "alcyone" + expand 1 + plot +.EE +.PP +Show a pretty galaxy. +.EX + ngc1300 + plate 10' +.EE +.SH FILES +.B /lib/sky/*.scat +.SH SOURCE +.B /sys/src/cmd/scat +.SH SEE ALSO +.IR astro (7) +.br +.B /lib/sky/constelnames\ \ +the three-letter abbreviations of the constellation names. +.PP +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. |