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.
You can download the latest version of IGRINS Observability on the Software Page.
IGRINS Observability has the following requirements:
- DS9 7.2 callable from the command line (might work on earlier versions)
- XPA for allowing commands to be given to DS9 from the command line
- Python 2.6 or 2.7 (untested on other versions)
- Scipy
- Matplotlib
Setting up input files.
For each target you want to make a finder chart for, you must set up an input file in the /input/ directory. Your basic input file will look like this:
#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------------------------------------------
135.0 #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=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 Name
#--------------------Guide Star Info---------------------------------------
0 #Input guide star as... 0=no guide star, 1=dRA & dDec, 2=RA & Dec., 3=guide star name
#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-band
I will now break down each of these seperately.
The first part lets the user set which charts to display. Set to 'y' to display a chart when running IGRINS Observability, set to 'n' to not display the chart.
y #Show telescope Hour Angle observing limits
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 recreation of this chart, with the declination of the target painted on as red circle.
y #Show altitude vs. Local Siderial Time plot with telescope observing limits
This is an altitude chart showing the altitude of the target above the horizon vs. local sidereal time as the blue line. The two red vertical lines show the observing limits of the telescope. These charts are designed to mimic the altitude charts created by http://catserver.ing.iac.es/staralt/ but currently lacks much of the functionality. If you want to create a night specific altitude chart for multiple objects, or want to see airmass, I recommend you use http://catserver.ing.iac.es/staralt/
y #Show finder chart for IGRINS Slit View Camera FOV
And here we get to the meat of the code, making a finder chart! The green outline is the Slit View Camera FOV. The box in the center is the slit. The Blue compass shows the directions of North and East. The rest of this manual will go into detail about creating finder charts.
