Moving objects with JS9 (AiM)

 

     Editing window:      
  
     You can display the movement of stellar objects by displaying several images with identical time intervals one after the other.
If you do not have your own images, you can load images from the Teide/Tenerife volcano (tfn) here for practice:

  • Save the "reduced" images on your computer:
         Teide/Tenerife       :      https://observe.lco.global/requests/2881362

  • Load the images into the Editing window:
    - (On the computer) JS9-Menu :   File ➔ open local ...
    Search for folder, activate all (nine) images and confirm with [Open].
    - (On the iPad) Open the Files App. Press the three dots at the top and bring the Files App and the browser window into the Split Screen:
    Select all images and drag them into the editing window.

  • JS9-Menu :  View ➔ Blinking
    provides an overview of the loaded images.

  • Tick the box [ ✓ ] blink for each image.

  • Set "blink rate" to "0.1".

  • Use the image number to check whether the images are shown in the correct order.
    (The order of the images can be changed by holding down the left mouse button.)

  • A tick at [ ✓ ] Blink Images shows the movement of the object.

  • Describe your observations in keywords!


Important tips:   
  • Sometimes the Fixed Stars are not quite fixed because there were problems with tracking during the observation or the telescope was instructed to follow the moving object.
    You can use the following function in the JS9 menu to try to stabilize the images:
    WCS   ➔   wcs reproject ...   ➔   all images in this display, using wcs.
    ( WCS stands for World Coordinat System: The program aligns the images according to the celestial coordinates provided in the FITS header. )
    Attention: Depending on the speed of your computer, this may take some time!!!
      
  • You may want to create a GIF animation of the movement for your school homepage. Then save some images of the sequence using
    File   ➔   save ...   ➔   PNG
    into a new folder. Upload these images to https://gifmaker.me and have a matching GIF animation created for free.
      
  • If you have stabilized the images using WCS (see above), changing the image sequence will also be easier:
    After zooming, moving, etc., simply click on all images once in the blinking window.

FURTHER * PRACTICAL * EXAMPLES


The JS9 application was adopted from CENTER FOR ASTROPHYSICS|HARVARD AND SMITHSONIAN and didactically reduced by us: https://js9.si.edu
The programme is subject to the MIT licence. Source code @GitHub
Astronomy and internet in Münster (AiM): http://www.aim-muenster.de
.