NOTE AS OF 2024 THIS SOFTWARE IS NOW OBSOLETE:  Please use the IGRINS Observing Planner for making IGRINS finder charts.

This page describes how to use my python code, IGRINS Observably, for making finder charts.  The finder charts are designed to match what you will see in the IGRINS slit view camera field of view.  They can be used for planning observations, and at the telescope to match what you are seeing in the slit view camera.

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You can download the latest version of IGRINS Observability on the Software Page. 

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IGRINS Observability has the following requirements:

• DS9 7.2 or above callable from the command line (might work on earlier versions).  You can install manually or with download and install manually from http://ds9.si.edu/site/Home.html or install with MacPorts.
• XPA for allowing commands to be given to DS9 from the command line.  If you are on a mac and have trouble installing XPA manually, try using Fink or MacPorts to install it.  After installing make sure the directory for xpaset, xpaget, and xpans is in your "Path" (as defined in .bash_profile or .cshrc), or else DS9 and XPA cannot interact.
• Python 2.6 or 2.7 (untested on other versions).  Easiest to install with pip or easy-installanaconda https://www.continuum.io/downloads.
• Scipy.  Easiest to install with with anaconda, pip or easy-install.
• Matplotlib.  Easiest to install with pip or easy-install.

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#Input file for making finder and observability charts
#--------------------Select Charts To Display---------------------------------------
y #Show telescope Hour Angle observing limits
y #Show altitude vs. Local Siderial Time plot with telescope observing limits
y #Show finder chart for IGRINS Slit View Camera FOV
#--------------------Target Info------------------------------------------
13590.0 #Sky Position Angle (Start north and go east, N=0, E=90, S=180, W=270 degrees, Default = 90 deg slit oriented east-west)
2 1 #1=Input object as RA & Dec., 2=Input object name
HD 219485 #Object Coordinates in RA & Dec [hh:mm:ss.ss<space>+/-hh:mm:ss.s], or Object Name22:36:24.53 +47:51:42.5
#--------------------Guide Star Info---------------------------------------
0 4 #Input guide star as... 0=no guide star, 1=dRA & dDec, 2=RA & Dec., 3=guide star name, 4=automatically find guide stars
#Guide star offset in dRA & dDec [arseconds<space>arcseconds], coordinates in RA & Dec [hh:mm:ss.ss<space>+/-hh:mm:ss.s], or Name
#--------------------User Supplied FITS File---------------------------------------
#Fits file path for making finder chart, leave blank if you just want to use 2MASS K-bandban

I will now break down each of these seperately.

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This displays a chart showing the limits of where the 2.7 m telescope can slew in Hour Angle and Declination.  The observing limit chart is a more up to date recreation of this old chart, with the declination of the target painted on as red circle.

Image RemovedImage Added

y #Show altitude vs. Local Siderial Time plot with telescope observing limits

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The first line sets the Position Angle (PA) of how you want the instrument's slit pointed at your target on the sky.  The PA goes clockwise from the North where  N=0, E=90, S=180, W=270 degrees.  The default rotation of the instrument is such that the the slit is oriented East to West, so normally the PA = 90 degrees.  WARNING: You should only rotate the instrument +/- 90 deg. from the default position to avoid entangling wires and hoses, so please try to limit your PA to 0-180 deg.  When rotating IGRINS, you will use the encoder on the instrument rotator.  See the Rotation PA -> Encoder table for IGRINS to convert PA to the number on the encoder.  The  From the PA you set will be reflected in how the sky is imaged in the FOV of the slit view camera, as shown below:

 , the code will calculate the rotator encoder setting and rotate the FOV in DS9 to properly reflect how it should look in the SVC, as shown below: