1. Select Open in the File menu (or click on  in the main Toolbar) to display the File Open box. Navigate to the Peranso Tutorials 8 folder. To do so, first locate your My Documents folder (typically C:\Users\<your_user_name>\Documents). In there is a subfolder Peranso, then select the subfolder Tutorials. Finally, select the folder 8. Determining the orbital period of eclipsing binaries. Select the file GSC 04433-00065 ASAS-SN and click the Open button.

  1. This loads the contents of the file and creates an Observations Window (ObsWin) with as caption GSC 04433-00065 ASAS-SN. ASAS-SN observations are made with V and g filters. Peranso groups all V observations in one Observation Set, and all g observations in another Observation Set. Your ObsWin hence contains two Observation Sets with a total of 3806 observations.

  2. Let's first modify the title of the ObsWin. Click anywhere on the title with the left mouse button. It displays the Change title label box. Enter GSC 04433-00065 (ASAS-SN) and click the OK button.

  3. As you can see, the two Observation Sets are not aligned. We will graphically align both sets. With the mouse anywhere over the dark green ObsSet, right click to display the context menu. From the context menu, select ObsSet and then select Time and Brightness offset. This displays the corresponding box, which is used to apply a time or brightness offset (displacement) to the selected ObsSet. 

    To graphically align the dark green ObsSet with the light green ObsSet using the mouse, you have to indicate start and end positions in the Observations Window. The distance between the start and end positions determines the offset values. 

    To determine the Brightness offset value, click the Use mouse button to the right of the Brightn. offset text box. The mouse cursor changes in an upwards arrow with a small 1 left of it, to indicate that you have to select the start position in the ObsWin. Click on an observation in the dark green ObsSet that is near mag 12.1 (which is the average magnitude of the ObsSet). 

    The mouse cursor now changes in an upwards arrow with a small 2 left of it, to indicate that you have to select the end position in the ObsWin. Move the mouse cursor to the light green ObsSet and click on an observation near the average ObsSet magnitude of 11.75 The Brightn. offset text field will now display the Brightness distance between the start and end positions. Click Apply to display the offset change in ObsWin and Close to get rid off the Time and Brightness offset box.

  4. Save the aligned ObsWin to a new file called GSC 04433-00065 ASAS-SN aligned. We will use it in the next two sections of this tutorial.