Generating lists of nearby catalog objects to a specific telescope pointing or from the header of a fits file is a useful tool to help find nearby focus stars or just to identify other objects in a sparse or crowded field. The tools scat and imcat can be used to generate lists of targets. From the text output cutting and pasting fields into the TUI slew window is easy to do. SCAT scat is a command line tool written by Doug Mink at SAO that queries any number of star catalog databases (see: scat and imcat catalogs for a list of searchable catalogs). Currently, APO supports the Tycho 2 (ty2), USNO A2 (ua2), and 2MASS IR (tmc) catalogs on newton.apo.nmsu.edu. A script wrapper has been written that automatically queries the RA/DEC of the 3.5m telescope and allows for searches of nearby stars to the current pointing position. To run scat, first login to newton under your institutions account. At the command line, for the simplest options use: scat -c catalog Examples: scat -c ty2 (For tycho 2 catalog) scat -c ua2 (For usno a2 catalog) scat -c tmc (For 2mass catalog) Executes the following flags: /usr/local/bin/scat.orig -c tyc2 -h -r 1800 -s p -n 10 -y 2000.0 RA DEC Sample output: USNO_A2_number RA2000 Dec2000 MagB MagR Plate Arcsec 0825.00624249 02:40:30.927 -00:55:29.89 10.3 9.7 591 13.94 0825.00624247 02:40:30.911 -00:55:45.63 16.5 17.1 591 21.52 0825.00624245 02:40:30.875 -00:55:09.49 19.8 19.2 591 23.52 0825.00624296 02:40:31.641 -00:55:37.26 17.4 18.0 591 25.97 0825.00624286 02:40:31.411 -00:54:16.95 19.9 18.3 591 75.09 0825.00623868 02:40:25.085 -00:55:55.09 18.1 17.3 591 78.20 0825.00623892 02:40:25.395 -00:54:41.37 17.0 17.0 591 83.90 0825.00623754 02:40:23.550 -00:55:53.95 18.1 17.7 591 99.90 You may add/replace any option flag for scat as follows. For a full list of options type "scat" or "scat.orig" scat.orig WCSTools 3.6.8, 6 April 2007, Doug Mink SAO List catalog sources in a region on the sky Usage: scat.orig -c catalog [arguments] ra dec system (J2000, B1950, etc.) or : scat.orig [arguments] list of catalog number ranges or : scat.orig [arguments] @file of either positions or numbers) -a: List single closest catalog source -b: Output B1950 (FK4) coordinates -d: Output RA and Dec in degrees instead of hms dms -e: Output ecliptic coordinates -f: Output search center for other programs -g: Output galactic coordinates -h: Print heading, else do not -i [length]: Print catalog object name, not catalog number (length optional) -j: Output J2000 (FK5) coordinates -k kwd: Add this keyword to output from tab table search -l: Print center and closest star on one line -mx mag1[,mag2]: Magnitude #x limit(s) (only one set allowed, default none) -n num: Number of brightest stars to print (-1=all as found) -o name: Object name -q year: Equinox of output positions in FITS date format or years -r rad: Search radius (<0=-half-width) in arcsec -r radi-rado: Inner and outer edges of search annulus in arcsec -r dx,dy: Search halfwidths in ra,dec in great circle arcseconds -rr dra,ddec: Search halfwidths in ra,dec in arcsec of RA and Dec -s d|e|mx|n|p|r: Sort by r=RA d=Dec mx=Mag#x n=none p=distance e=merge -t: Tab table to standard output as well as file -u x y: Print x y instead of number in front of non-tab entry -v: Verbose IMCAT imcat is a command line tool written by Doug Mink at SAO that queries the WCS coordinates from a FITS file and lists all objects from a user specified catalog database that should appear in that image along with RA/DEC and pixel positions of each object (see: scat and imcat catalogs for a list of searchable catalogs). Currently, APO supports the Tycho 2 (ty2), USNO A2 (ua2), and 2MASS IR (tmc) catalogs on newton.apo.nmsu.edu. To run imcat, first login to newton under your institutions account. At the command line, for the simplest options use: imcat -c catalog file.fits Examples: imcat -c ty2 /export/images/Q4UW08/UT081103/myobject.0001.fits (For tycho 2 catalog) imcat -c ua2 /export/images/Q4UW08/UT081103/myobject.0001.fits (For usno a2 catalog) imcat -c tmc /export/images/Q4UW08/UT081103/myobject.0001.fits (For 2mass catalog) Sample Output: USNO_A2_number RA DEC MagB MagR Plate X Y 0825.00624249 02:40:30.927 -00:55:29.89 10.3 9.7 591 1073.8 608.8 0825.00624617 02:40:36.601 -00:40:35.90 10.3 9.7 591 1026.1 1135.0 0825.00628034 02:41:29.421 -00:52:59.06 10.3 9.8 591 558.1 699.9 0825.00626686 02:41:09.292 -01:05:42.64 11.2 9.8 591 733.6 249.9 0825.00627723 02:41:24.776 -01:08:07.47 11.2 9.1 591 596.6 165.3 0825.00626956 02:41:13.329 -00:41:39.62 11.4 10.5 591 701.9 1099.0 0825.00628305 02:41:33.491 -01:01:02.84 11.5 10.4 591 520.9 415.5 The imcat wrapper uses the same default options as described above with scat. You may add/replace any option flag for imcat as follows. For a full list of options type "imcat" or "imcat.orig" imcat WCSTools 3.6.8, 6 April 2007, Doug Mink (dmink@cfa.harvard.edu) List catalog sources in FITS and IRAF image files Usage: [-vhst] [-m [mag1] mag2] [-g class] [-p scale][-q osd+x][-b ra dec][-j ra dec][-r arcsec] FITS or IRAF file(s) -a: initial rotation angle in degrees (default 0) -b [RA Dec]: Output, (center) in B1950 (FK4) RA and Dec -c name: Reference catalog (gsc, ua2, local file, etc. -d: Output RA,Dec positions in fractional degrees -e: Output in ecliptic longitude and latitude -f: Print only number of stars found, nothing else -g: Output in galactic longitude and latitude -h: Print heading, else do not -i: Print name instead of number in region file -j [RA Dec]: Output (center) in J2000 (FK5) RA and Dec -k keyword: Add this keyword to output from tab table search -mx m1[,m2]: Catalog magnitude #x limit(s) (only one set allowed, default none) -n num: Number of brightest stars to print -o name: Set HST Guide Star object class to print -p num: Initial plate scale in arcsec per pixel (default 0) -q osdv+x[p]: Write SAOimage region file of this shape (filename.cat) -r num[,num]: Write SAOimage region file of this radius [range] (filename.cat) -s d|mx|n|r|x|y: Sort by r=RA d=Dec mx=Mag#x n=none x=X y=Y -t: Tab table to standard output as well as file -u num: USNO catalog single plate number to accept -v: Verbose -w: Write tab table output file [imagename].[catalog] -x x y: X and Y coordinates of reference pixel (default is center) -y date: Epoch of image in FITS date format or year -z: Use AIPS classic projections instead of WCSLIB
Generating lists of nearby catalog objects to a specific telescope pointing or from the header of a fits file is a useful tool to help find nearby focus stars or just to identify other objects in a sparse or crowded field. The tools scat and imcat can be used to generate lists of targets. From the text output cutting and pasting fields into the TUI slew window is easy to do.
scat is a command line tool written by Doug Mink at SAO that queries any number of star catalog databases (see: scat and imcat catalogs for a list of searchable catalogs). Currently, APO supports the Tycho 2 (ty2), USNO A2 (ua2), and 2MASS IR (tmc) catalogs on newton.apo.nmsu.edu. A script wrapper has been written that automatically queries the RA/DEC of the 3.5m telescope and allows for searches of nearby stars to the current pointing position. To run scat, first login to newton under your institutions account. At the command line, for the simplest options use: scat -c catalog Examples: scat -c ty2 (For tycho 2 catalog) scat -c ua2 (For usno a2 catalog) scat -c tmc (For 2mass catalog) Executes the following flags: /usr/local/bin/scat.orig -c tyc2 -h -r 1800 -s p -n 10 -y 2000.0 RA DEC Sample output: USNO_A2_number RA2000 Dec2000 MagB MagR Plate Arcsec 0825.00624249 02:40:30.927 -00:55:29.89 10.3 9.7 591 13.94 0825.00624247 02:40:30.911 -00:55:45.63 16.5 17.1 591 21.52 0825.00624245 02:40:30.875 -00:55:09.49 19.8 19.2 591 23.52 0825.00624296 02:40:31.641 -00:55:37.26 17.4 18.0 591 25.97 0825.00624286 02:40:31.411 -00:54:16.95 19.9 18.3 591 75.09 0825.00623868 02:40:25.085 -00:55:55.09 18.1 17.3 591 78.20 0825.00623892 02:40:25.395 -00:54:41.37 17.0 17.0 591 83.90 0825.00623754 02:40:23.550 -00:55:53.95 18.1 17.7 591 99.90 You may add/replace any option flag for scat as follows. For a full list of options type "scat" or "scat.orig" scat.orig WCSTools 3.6.8, 6 April 2007, Doug Mink SAO List catalog sources in a region on the sky Usage: scat.orig -c catalog [arguments] ra dec system (J2000, B1950, etc.) or : scat.orig [arguments] list of catalog number ranges or : scat.orig [arguments] @file of either positions or numbers) -a: List single closest catalog source -b: Output B1950 (FK4) coordinates -d: Output RA and Dec in degrees instead of hms dms -e: Output ecliptic coordinates -f: Output search center for other programs -g: Output galactic coordinates -h: Print heading, else do not -i [length]: Print catalog object name, not catalog number (length optional) -j: Output J2000 (FK5) coordinates -k kwd: Add this keyword to output from tab table search -l: Print center and closest star on one line -mx mag1[,mag2]: Magnitude #x limit(s) (only one set allowed, default none) -n num: Number of brightest stars to print (-1=all as found) -o name: Object name -q year: Equinox of output positions in FITS date format or years -r rad: Search radius (<0=-half-width) in arcsec -r radi-rado: Inner and outer edges of search annulus in arcsec -r dx,dy: Search halfwidths in ra,dec in great circle arcseconds -rr dra,ddec: Search halfwidths in ra,dec in arcsec of RA and Dec -s d|e|mx|n|p|r: Sort by r=RA d=Dec mx=Mag#x n=none p=distance e=merge -t: Tab table to standard output as well as file -u x y: Print x y instead of number in front of non-tab entry -v: Verbose
scat is a command line tool written by Doug Mink at SAO that queries any number of star catalog databases (see: scat and imcat catalogs for a list of searchable catalogs). Currently, APO supports the Tycho 2 (ty2), USNO A2 (ua2), and 2MASS IR (tmc) catalogs on newton.apo.nmsu.edu. A script wrapper has been written that automatically queries the RA/DEC of the 3.5m telescope and allows for searches of nearby stars to the current pointing position.
To run scat, first login to newton under your institutions account. At the command line, for the simplest options use:
scat -c catalog Examples: scat -c ty2 (For tycho 2 catalog) scat -c ua2 (For usno a2 catalog) scat -c tmc (For 2mass catalog) Executes the following flags: /usr/local/bin/scat.orig -c tyc2 -h -r 1800 -s p -n 10 -y 2000.0 RA DEC Sample output: USNO_A2_number RA2000 Dec2000 MagB MagR Plate Arcsec 0825.00624249 02:40:30.927 -00:55:29.89 10.3 9.7 591 13.94 0825.00624247 02:40:30.911 -00:55:45.63 16.5 17.1 591 21.52 0825.00624245 02:40:30.875 -00:55:09.49 19.8 19.2 591 23.52 0825.00624296 02:40:31.641 -00:55:37.26 17.4 18.0 591 25.97 0825.00624286 02:40:31.411 -00:54:16.95 19.9 18.3 591 75.09 0825.00623868 02:40:25.085 -00:55:55.09 18.1 17.3 591 78.20 0825.00623892 02:40:25.395 -00:54:41.37 17.0 17.0 591 83.90 0825.00623754 02:40:23.550 -00:55:53.95 18.1 17.7 591 99.90
You may add/replace any option flag for scat as follows. For a full list of options type "scat" or "scat.orig" scat.orig WCSTools 3.6.8, 6 April 2007, Doug Mink SAO List catalog sources in a region on the sky Usage: scat.orig -c catalog [arguments] ra dec system (J2000, B1950, etc.) or : scat.orig [arguments] list of catalog number ranges or : scat.orig [arguments] @file of either positions or numbers) -a: List single closest catalog source -b: Output B1950 (FK4) coordinates -d: Output RA and Dec in degrees instead of hms dms -e: Output ecliptic coordinates -f: Output search center for other programs -g: Output galactic coordinates -h: Print heading, else do not -i [length]: Print catalog object name, not catalog number (length optional) -j: Output J2000 (FK5) coordinates -k kwd: Add this keyword to output from tab table search -l: Print center and closest star on one line -mx mag1[,mag2]: Magnitude #x limit(s) (only one set allowed, default none) -n num: Number of brightest stars to print (-1=all as found) -o name: Object name -q year: Equinox of output positions in FITS date format or years -r rad: Search radius (<0=-half-width) in arcsec -r radi-rado: Inner and outer edges of search annulus in arcsec -r dx,dy: Search halfwidths in ra,dec in great circle arcseconds -rr dra,ddec: Search halfwidths in ra,dec in arcsec of RA and Dec -s d|e|mx|n|p|r: Sort by r=RA d=Dec mx=Mag#x n=none p=distance e=merge -t: Tab table to standard output as well as file -u x y: Print x y instead of number in front of non-tab entry -v: Verbose
imcat is a command line tool written by Doug Mink at SAO that queries the WCS coordinates from a FITS file and lists all objects from a user specified catalog database that should appear in that image along with RA/DEC and pixel positions of each object (see: scat and imcat catalogs for a list of searchable catalogs). Currently, APO supports the Tycho 2 (ty2), USNO A2 (ua2), and 2MASS IR (tmc) catalogs on newton.apo.nmsu.edu. To run imcat, first login to newton under your institutions account. At the command line, for the simplest options use: imcat -c catalog file.fits Examples: imcat -c ty2 /export/images/Q4UW08/UT081103/myobject.0001.fits (For tycho 2 catalog) imcat -c ua2 /export/images/Q4UW08/UT081103/myobject.0001.fits (For usno a2 catalog) imcat -c tmc /export/images/Q4UW08/UT081103/myobject.0001.fits (For 2mass catalog) Sample Output: USNO_A2_number RA DEC MagB MagR Plate X Y 0825.00624249 02:40:30.927 -00:55:29.89 10.3 9.7 591 1073.8 608.8 0825.00624617 02:40:36.601 -00:40:35.90 10.3 9.7 591 1026.1 1135.0 0825.00628034 02:41:29.421 -00:52:59.06 10.3 9.8 591 558.1 699.9 0825.00626686 02:41:09.292 -01:05:42.64 11.2 9.8 591 733.6 249.9 0825.00627723 02:41:24.776 -01:08:07.47 11.2 9.1 591 596.6 165.3 0825.00626956 02:41:13.329 -00:41:39.62 11.4 10.5 591 701.9 1099.0 0825.00628305 02:41:33.491 -01:01:02.84 11.5 10.4 591 520.9 415.5 The imcat wrapper uses the same default options as described above with scat. You may add/replace any option flag for imcat as follows. For a full list of options type "imcat" or "imcat.orig" imcat WCSTools 3.6.8, 6 April 2007, Doug Mink (dmink@cfa.harvard.edu) List catalog sources in FITS and IRAF image files Usage: [-vhst] [-m [mag1] mag2] [-g class] [-p scale][-q osd+x][-b ra dec][-j ra dec][-r arcsec] FITS or IRAF file(s) -a: initial rotation angle in degrees (default 0) -b [RA Dec]: Output, (center) in B1950 (FK4) RA and Dec -c name: Reference catalog (gsc, ua2, local file, etc. -d: Output RA,Dec positions in fractional degrees -e: Output in ecliptic longitude and latitude -f: Print only number of stars found, nothing else -g: Output in galactic longitude and latitude -h: Print heading, else do not -i: Print name instead of number in region file -j [RA Dec]: Output (center) in J2000 (FK5) RA and Dec -k keyword: Add this keyword to output from tab table search -mx m1[,m2]: Catalog magnitude #x limit(s) (only one set allowed, default none) -n num: Number of brightest stars to print -o name: Set HST Guide Star object class to print -p num: Initial plate scale in arcsec per pixel (default 0) -q osdv+x[p]: Write SAOimage region file of this shape (filename.cat) -r num[,num]: Write SAOimage region file of this radius [range] (filename.cat) -s d|mx|n|r|x|y: Sort by r=RA d=Dec mx=Mag#x n=none x=X y=Y -t: Tab table to standard output as well as file -u num: USNO catalog single plate number to accept -v: Verbose -w: Write tab table output file [imagename].[catalog] -x x y: X and Y coordinates of reference pixel (default is center) -y date: Epoch of image in FITS date format or year -z: Use AIPS classic projections instead of WCSLIB
imcat is a command line tool written by Doug Mink at SAO that queries the WCS coordinates from a FITS file and lists all objects from a user specified catalog database that should appear in that image along with RA/DEC and pixel positions of each object (see: scat and imcat catalogs for a list of searchable catalogs). Currently, APO supports the Tycho 2 (ty2), USNO A2 (ua2), and 2MASS IR (tmc) catalogs on newton.apo.nmsu.edu.
To run imcat, first login to newton under your institutions account. At the command line, for the simplest options use:
imcat -c catalog file.fits Examples: imcat -c ty2 /export/images/Q4UW08/UT081103/myobject.0001.fits (For tycho 2 catalog) imcat -c ua2 /export/images/Q4UW08/UT081103/myobject.0001.fits (For usno a2 catalog) imcat -c tmc /export/images/Q4UW08/UT081103/myobject.0001.fits (For 2mass catalog) Sample Output: USNO_A2_number RA DEC MagB MagR Plate X Y 0825.00624249 02:40:30.927 -00:55:29.89 10.3 9.7 591 1073.8 608.8 0825.00624617 02:40:36.601 -00:40:35.90 10.3 9.7 591 1026.1 1135.0 0825.00628034 02:41:29.421 -00:52:59.06 10.3 9.8 591 558.1 699.9 0825.00626686 02:41:09.292 -01:05:42.64 11.2 9.8 591 733.6 249.9 0825.00627723 02:41:24.776 -01:08:07.47 11.2 9.1 591 596.6 165.3 0825.00626956 02:41:13.329 -00:41:39.62 11.4 10.5 591 701.9 1099.0 0825.00628305 02:41:33.491 -01:01:02.84 11.5 10.4 591 520.9 415.5 The imcat wrapper uses the same default options as described above with scat. You may add/replace any option flag for imcat as follows. For a full list of options type "imcat" or "imcat.orig" imcat WCSTools 3.6.8, 6 April 2007, Doug Mink (dmink@cfa.harvard.edu) List catalog sources in FITS and IRAF image files Usage: [-vhst] [-m [mag1] mag2] [-g class] [-p scale][-q osd+x][-b ra dec][-j ra dec][-r arcsec] FITS or IRAF file(s) -a: initial rotation angle in degrees (default 0) -b [RA Dec]: Output, (center) in B1950 (FK4) RA and Dec -c name: Reference catalog (gsc, ua2, local file, etc. -d: Output RA,Dec positions in fractional degrees -e: Output in ecliptic longitude and latitude -f: Print only number of stars found, nothing else -g: Output in galactic longitude and latitude -h: Print heading, else do not -i: Print name instead of number in region file -j [RA Dec]: Output (center) in J2000 (FK5) RA and Dec -k keyword: Add this keyword to output from tab table search -mx m1[,m2]: Catalog magnitude #x limit(s) (only one set allowed, default none) -n num: Number of brightest stars to print -o name: Set HST Guide Star object class to print -p num: Initial plate scale in arcsec per pixel (default 0) -q osdv+x[p]: Write SAOimage region file of this shape (filename.cat) -r num[,num]: Write SAOimage region file of this radius [range] (filename.cat) -s d|mx|n|r|x|y: Sort by r=RA d=Dec mx=Mag#x n=none x=X y=Y -t: Tab table to standard output as well as file -u num: USNO catalog single plate number to accept -v: Verbose -w: Write tab table output file [imagename].[catalog] -x x y: X and Y coordinates of reference pixel (default is center) -y date: Epoch of image in FITS date format or year -z: Use AIPS classic projections instead of WCSLIB
SAOIMAGE DS9 created charts on the fly You can generate a finder chart quickly in DS9 to verify the telescope is pointing to the proper location. Charts can be made from the Digitized Sky Survey, the 2Mass survery, the VLA Radio FIRST survey or Skyview. Load an image into DS9 using the File>Open... utility. Note: Loading an image with IRAF will not work. IRAF does not pass on the WCS information to DS9. Select an image server from the Analysis Menu Double check the WCS coordinates of your object then press Retrieve A finder chart appears in the next available frame of DS9. Make sure you have Frames set to Tile to display each side by side APO GUIDE CHARTS The user, as part of their pre-observational planning, can take the guess work out of wether there will be a star bright enough for guiding for each field they wish to observe. Wether they are doing long slit spectroscopy with DIS or imaging with any of the other NA2 instruments it is helpful to plan for a guide staar before your observations begin. The NA2 off axis guider may be used for guiding or in conjunction with autofocus routines. Setting the field rotation of the instrument to ensure a bright enough object appears on the NA2 guider for guiding is to your benefit. APO provides a webpage based tool for generating finder charts (FITS format) and charts with overlays (PDF format) to help the observer locate guide stars for the NA2 guider. The APO guider aquisition form may be found at: www.apo.nmsu.edu/~apoguide/ Follow the instructions on the form and submit your list of objects. After a short time you will recieve an email with instructions on how to retrieve your finder charts. An example list of targets in the form might look like the following: "SN30", "02:18:02.3", "-00:33:32.4", "DIS-SLIT, 146.0 "SN18", "02:41:12.6", "-00:52:45.9", "SPICAM", 0.0 "SN128", "02:15:54.3", "+01:04:09.9", "DIS-SLIT", -10.0 "SN129", "03:51:20.7", "+01:10:35.5", "DIS-SLIT", -40.0 "SN111", "20:40:48.0", "+01:02:34.2", "DIS-SLIT", -14.0 "SN83", "22:01:46.6", "+01:14:12.0", "DIS-SLIT", -5.0 The finished job will appear as a list of processed files such as: "SN30", "02:18:02.3", "-00:33:32.4", "DIS-SLIT, 146.0 "SN18", "02:41:12.6", "-00:52:45.9", "SPICAM", 0.0 "SN128", "02:15:54.3", "+01:04:09.9", "DIS-SLIT", -10.0 "SN129", "03:51:20.7", "+01:10:35.5", "DIS-SLIT", -40.0 "SN111", "20:40:48.0", "+01:02:34.2", "DIS-SLIT", -14.0 "SN83", "22:01:46.6", "+01:14:12.0", "DIS-SLIT", -5.0 Request - 482B SN111.fits - 3M SN111.fits.gz - 1M SN111.pdf - 210K SN111.usno2.dat - 2B SN128.fits - 3M SN128.fits.gz - 1M SN128.pdf - 74K SN128.usno2.dat - 2B SN129.fits - 3M SN129.fits.gz - 1M SN129.pdf - 72K SN129.usno2.dat - 2B SN18.fits - 3M SN18.fits.gz - 1M SN18.pdf - 91K SN18.usno2.dat - 2B SN83.fits - 3M SN83.fits.gz - 1M SN83.pdf - 93K SN83.usno2.dat - 2B The FITS (or FITS.gz) file is a finder chart without a graphical overlay. The PDF file that is generated for each source will look somewhat like this: The chart overlay shows a center square which represents the size of the field of view of the instrument specified for this field. A + sign designates the location of the object you wish to point the telescope to. The X-Y arrows show the directions of ObjectXY (inside the box) and Boresight (outside the box) offsets. A circular annulus surrounds the inner box. This shows all the stars that could be available to the NA2 guider. The small boxes inside this annulus show the field of view of the guider at various field rotations of the instrument. In this particular example the default instrument angle of ROTANG=0, the guider will be seeing the objects displayed in the small box on the left side of the page. If a ROTANG=90 was specified for the instrument rotator then the guider would be looking at the field at the bottom of the annulus. Rotation angles (ROTANG) of 0 to +/- 180 may be specified for most instruments in order to find suitable guide stars. Ask your observing specialist if you have question on the rotation limits of an instrument you wish to use.
You can generate a finder chart quickly in DS9 to verify the telescope is pointing to the proper location. Charts can be made from the Digitized Sky Survey, the 2Mass survery, the VLA Radio FIRST survey or Skyview. Load an image into DS9 using the File>Open... utility. Note: Loading an image with IRAF will not work. IRAF does not pass on the WCS information to DS9. Select an image server from the Analysis Menu Double check the WCS coordinates of your object then press Retrieve A finder chart appears in the next available frame of DS9. Make sure you have Frames set to Tile to display each side by side
You can generate a finder chart quickly in DS9 to verify the telescope is pointing to the proper location. Charts can be made from the Digitized Sky Survey, the 2Mass survery, the VLA Radio FIRST survey or Skyview.
Load an image into DS9 using the File>Open... utility. Note: Loading an image with IRAF will not work. IRAF does not pass on the WCS information to DS9.
Select an image server from the Analysis Menu
Double check the WCS coordinates of your object then press Retrieve
A finder chart appears in the next available frame of DS9. Make sure you have Frames set to Tile to display each side by side
The user, as part of their pre-observational planning, can take the guess work out of wether there will be a star bright enough for guiding for each field they wish to observe. Wether they are doing long slit spectroscopy with DIS or imaging with any of the other NA2 instruments it is helpful to plan for a guide staar before your observations begin. The NA2 off axis guider may be used for guiding or in conjunction with autofocus routines. Setting the field rotation of the instrument to ensure a bright enough object appears on the NA2 guider for guiding is to your benefit. APO provides a webpage based tool for generating finder charts (FITS format) and charts with overlays (PDF format) to help the observer locate guide stars for the NA2 guider. The APO guider aquisition form may be found at: www.apo.nmsu.edu/~apoguide/ Follow the instructions on the form and submit your list of objects. After a short time you will recieve an email with instructions on how to retrieve your finder charts. An example list of targets in the form might look like the following: "SN30", "02:18:02.3", "-00:33:32.4", "DIS-SLIT, 146.0 "SN18", "02:41:12.6", "-00:52:45.9", "SPICAM", 0.0 "SN128", "02:15:54.3", "+01:04:09.9", "DIS-SLIT", -10.0 "SN129", "03:51:20.7", "+01:10:35.5", "DIS-SLIT", -40.0 "SN111", "20:40:48.0", "+01:02:34.2", "DIS-SLIT", -14.0 "SN83", "22:01:46.6", "+01:14:12.0", "DIS-SLIT", -5.0 The finished job will appear as a list of processed files such as: "SN30", "02:18:02.3", "-00:33:32.4", "DIS-SLIT, 146.0 "SN18", "02:41:12.6", "-00:52:45.9", "SPICAM", 0.0 "SN128", "02:15:54.3", "+01:04:09.9", "DIS-SLIT", -10.0 "SN129", "03:51:20.7", "+01:10:35.5", "DIS-SLIT", -40.0 "SN111", "20:40:48.0", "+01:02:34.2", "DIS-SLIT", -14.0 "SN83", "22:01:46.6", "+01:14:12.0", "DIS-SLIT", -5.0 Request - 482B SN111.fits - 3M SN111.fits.gz - 1M SN111.pdf - 210K SN111.usno2.dat - 2B SN128.fits - 3M SN128.fits.gz - 1M SN128.pdf - 74K SN128.usno2.dat - 2B SN129.fits - 3M SN129.fits.gz - 1M SN129.pdf - 72K SN129.usno2.dat - 2B SN18.fits - 3M SN18.fits.gz - 1M SN18.pdf - 91K SN18.usno2.dat - 2B SN83.fits - 3M SN83.fits.gz - 1M SN83.pdf - 93K SN83.usno2.dat - 2B The FITS (or FITS.gz) file is a finder chart without a graphical overlay. The PDF file that is generated for each source will look somewhat like this: The chart overlay shows a center square which represents the size of the field of view of the instrument specified for this field. A + sign designates the location of the object you wish to point the telescope to. The X-Y arrows show the directions of ObjectXY (inside the box) and Boresight (outside the box) offsets. A circular annulus surrounds the inner box. This shows all the stars that could be available to the NA2 guider. The small boxes inside this annulus show the field of view of the guider at various field rotations of the instrument. In this particular example the default instrument angle of ROTANG=0, the guider will be seeing the objects displayed in the small box on the left side of the page. If a ROTANG=90 was specified for the instrument rotator then the guider would be looking at the field at the bottom of the annulus. Rotation angles (ROTANG) of 0 to +/- 180 may be specified for most instruments in order to find suitable guide stars. Ask your observing specialist if you have question on the rotation limits of an instrument you wish to use.
The user, as part of their pre-observational planning, can take the guess work out of wether there will be a star bright enough for guiding for each field they wish to observe. Wether they are doing long slit spectroscopy with DIS or imaging with any of the other NA2 instruments it is helpful to plan for a guide staar before your observations begin. The NA2 off axis guider may be used for guiding or in conjunction with autofocus routines. Setting the field rotation of the instrument to ensure a bright enough object appears on the NA2 guider for guiding is to your benefit. APO provides a webpage based tool for generating finder charts (FITS format) and charts with overlays (PDF format) to help the observer locate guide stars for the NA2 guider. The APO guider aquisition form may be found at: www.apo.nmsu.edu/~apoguide/
Follow the instructions on the form and submit your list of objects. After a short time you will recieve an email with instructions on how to retrieve your finder charts.
An example list of targets in the form might look like the following: "SN30", "02:18:02.3", "-00:33:32.4", "DIS-SLIT, 146.0 "SN18", "02:41:12.6", "-00:52:45.9", "SPICAM", 0.0 "SN128", "02:15:54.3", "+01:04:09.9", "DIS-SLIT", -10.0 "SN129", "03:51:20.7", "+01:10:35.5", "DIS-SLIT", -40.0 "SN111", "20:40:48.0", "+01:02:34.2", "DIS-SLIT", -14.0 "SN83", "22:01:46.6", "+01:14:12.0", "DIS-SLIT", -5.0 The finished job will appear as a list of processed files such as: "SN30", "02:18:02.3", "-00:33:32.4", "DIS-SLIT, 146.0 "SN18", "02:41:12.6", "-00:52:45.9", "SPICAM", 0.0 "SN128", "02:15:54.3", "+01:04:09.9", "DIS-SLIT", -10.0 "SN129", "03:51:20.7", "+01:10:35.5", "DIS-SLIT", -40.0 "SN111", "20:40:48.0", "+01:02:34.2", "DIS-SLIT", -14.0 "SN83", "22:01:46.6", "+01:14:12.0", "DIS-SLIT", -5.0
The FITS (or FITS.gz) file is a finder chart without a graphical overlay.
The PDF file that is generated for each source will look somewhat like this:
The chart overlay shows a center square which represents the size of the field of view of the instrument specified for this field. A + sign designates the location of the object you wish to point the telescope to. The X-Y arrows show the directions of ObjectXY (inside the box) and Boresight (outside the box) offsets. A circular annulus surrounds the inner box. This shows all the stars that could be available to the NA2 guider. The small boxes inside this annulus show the field of view of the guider at various field rotations of the instrument. In this particular example the default instrument angle of ROTANG=0, the guider will be seeing the objects displayed in the small box on the left side of the page. If a ROTANG=90 was specified for the instrument rotator then the guider would be looking at the field at the bottom of the annulus. Rotation angles (ROTANG) of 0 to +/- 180 may be specified for most instruments in order to find suitable guide stars. Ask your observing specialist if you have question on the rotation limits of an instrument you wish to use.
