Next: 4. Starting fitsblink Up: Fitsblink 2.1 user manual Previous: 2. Installation
Subsections

- 3.1 Installing and running for the first time
- 3.2 First blink
- 3.3 Star detection
- 3.4 Matching the catalog
- 3.5 Reading object positions
- 3.6 Astrometry reports
- 3.7 Markers

# 3. Quick start tutorial

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.

## 3.1 Installing and running for the first time

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.

## 3.2 First blink

Now press the left Load button and choose `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.

## 3.3 Star detection

Before you can do astrometry, stars have to be detected. Open the Astrometry menu and choose Detect stars. The detected objects will be marked by red circles. You may want to change sensitivity. Choose Options, change values in the Star counting frame and run Detect stars again. After that, press the Defaults button and detect stars again.

## 3.4 Matching the catalog

By now you have already detected objects and you want to get the coordinates of that moving object you spotted in the blinking images. Things become a little more real now: you need either GSC 1.1 or USNO SA 1.0 catalog. Typically, you will have them on a CDROM. If you haven't done so before, mount the CDROM somewhere in your file system. Choose the Catalogs item and write in the mounting point of the catalog. Also, press the check button for the catalog you have. Then choose Edit parameters and write in approximate coordinates of the image center: RA=14h50m and DEC=0d22'. Pixel sizes should be already written in: 1.92'' in both directions. Do not forget to press return or tabulator after you write values in the input fields! Now choose Match stars and see what happens. If you followed the previous steps, you should get a successful match with the default parameters regardless whether you used GSC or USNO SA catalog..

## 3.5 Reading object positions

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

## 3.6 Astrometry reports

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.

## 3.7 Markers

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.

Next: 4. Starting fitsblink Up: Fitsblink 2.1 user manual Previous: 2. Installation