How to measure your images

open an X window

click X icon

THE FIRST TIME THROUGH ONLY

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create a new folder

mkdir ‘dir’

move to it

cd ‘dir’

create an IRAF start up file

mkiraf

answer xgterm to first question and y to second question

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open an xgterm window

xgterm

in the xgterm window open display window in the background

ds9 &

open IRAF

cl

A lot of stuff prints out, then you can do IRAF commands.

Go to a directory with images using cd

to display an image:

disp imagename fill+ [does not need .fit]

to measure magnitude and position type

imexam 'imagename'

When you move your cursor into the ds9 window, it will blink

Center it on a star and hit the “a” key

You will get the x[col],y[line] coordinate displayed as well as MAG, which is the magnitude [in the second line]. E is the error of the measurement.

When you get finished type “q” while the cursor is in the display window.

When you finish with everything logout of IRAF.

lo

imexam will also do a series of images if you use a wildcard and then hit “n” while in the display window to move to the next image.

There is also a way to write your output to a file.

start with

imexam 'imagename' logfile='filename'

Then when in the display window

type “w” {opens the file]

do your photometry

type “w” [closes the file]

“q” exits

The file is in the directory with the images.