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Tips 'n Tricks
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Tips 'n Tricks
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| Slice |   Use slice to
see a profile of the brightness counts along a line or to measure distance
in pixels. Go to the Data Tools menu and select Slice. Move
your cursor to the image. Click the mouse and drag across to make a
line; release the mouse button. You may need to move the slice window
out of the way, since it usually opens over the image.
Click and drag the mouse on the graph or the slice line. Watch the numbers change in the Slice graph window. Distance is in pixels across the slice line. Counts are brightness counts of each pixel. |
| Auto Aperture |  Click on Auto Aperture  and move your cursor over a
star. Click again. The number which appears on the screen represents
the star's total counts of brightness as recorded by the CCD camera in all
the pixels where the star's light falls, minus the background sky.
This number will vary according to observing conditions, exposure times,
and filters. To do another star, click Auto Aperture again. |
| Results Box |  Results keeps track of your
data. Note the name of the file and position of the star (x,y).
Note brightness of the star, and the sky. Radius refers to the pixel width
of the star at half the maximum brightness of the star. Sky radius
is twice the star radius. HOU-IP software samples the sky around the
star at this radius and subtracts the average sky brightness counts so the
Brightness value is only the light from the star itself.
Sometimes, Results pops open on top of your screen, just move it out of the way. Or, go to File; choose Hide Window. You can also save the Results as a file; type in a name such as ringnebdata.txt. Be sure to type the extension .txt after the name. Under Edit, you can also Copy or Erase data. |
