man/man1/scat.1 - plan9 - Git at Google

 .TH SCAT 1
 .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 (1)
 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 (1).
 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
 .IR 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 (1)
 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 \*9/sky/*.scat
 .SH SOURCE
 .B \*9/src/cmd/scat
 .SH SEE ALSO
 .IR astro (1)
 .br
 .B \*9/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.
	.TH SCAT 1
	.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 (1)
	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 (1).
	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
	.IR 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 (1)
	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 \9/sky/.scat
	.SH SOURCE
	.B \*9/src/cmd/scat
	.SH SEE ALSO
	.IR astro (1)
	.br
	.B \*9/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.