This section lets you go through some of the fitsblink
functions without reading the rest of the manual, just to get some
overview of the available functions.
Apart from a working fitsblink
program you also need the
example images which can be found on the fitsblink
home page.
Un-tar the file by typing tar xf examples.tar
. A directory
named fitsblink_examples
will be created and you will find
there the following files:
98kd3r5-98kd3r6.inp 98kd3r5.dat 98kd3r5.fts.gz 98kd3r6.dat 98kd3r6.fts.gz coordinates
Go to the fitsblink_examples
directory and start
fitsblink
. If the $HOME/.fitsblinkrc
file does not
exist yet, fitsblink
will complain. Just press OK
button and from the Astrometry menu choose Settings
item. Set all of the settings and save them by pressing the
Save button. Next time you run fitsblink
it should
not complain anymore about the missing parameter file.
98kd3r5.fts.gz
file. The image will be loaded and displayed in
the blink window. Repeat this procedure with the
98kd3r6.fts.gz
file. Now you have two images in the memory and
you can blink them just by pressing the Blink button. The
images will be alternately displayed on the screen. You can adjust
blinking frequency with the Delay counter. You noticed that
the images are not aligned perfectly. So, center a star in the left
small window with the magnified image and double-click on it. Four
cursor buttons will appear. Click on them until small images are
aligned and then press the button with a blue circle. The images will
be aligned now. If you look for a moving obejcts, you will find one
right to the center of the screen. To stop blinking, press
Blink again.
As soon you detect stars, you can also get their positions by pressing
the RIGHT mouse button when you are close to one of the DETECTED
objects. A window with a magnified part of the image around the
object position will appear. You will also get object x and y coordinates. If the WCS values are present in the image header or if
you made a successful match with catalog stars, you will also see the
object's celestial coordinates. For the example image
98kd3r5.fts.gz
the coordinates of the moving object are:
Catalog | RA | Dec. |
GSC 1.1 | 14:50:00.61 | 00:20:27.0 |
GSC 1.1 + USNO SA 1.0 | 14:50:00.61 | 00:20:26.7 |
USNO SA 1.0 | 14:50:00.60 | 00:20:26.6 |
There is another way to get object coordinates: choose the Do astrometry item. You will see the cursor change shape into a cross. Now press the LEFT mouse button on a selected object. If you are happy with it, press OK in the window that appears, type in the object name an astrometry report window will appear. For more details about this, see sections 12.3 and 12.4.
Another interesting feature of fitsblink
are markers. You
already saw them if you detected stars and matched them with a
catalog. You can find some examples of the use of markers in the file
98kd3r5-98kd3r6.inp
. From the command line run
fitsblink -i 98kd3r5-98kd3r6.inp
and see what happens.
This concludes the quick overview of the main fitsblink
functions.