GSoC/GCI Archive
Google Code-in 2012 KDE

Marble: Add more DSOs and Constellations to the Stars Plugin

completed by: Timothy Lanzi

mentors: Torsten Rahn, René Küttner, Dennis Nienhüser

During Google Code-In the Stars Plugin has been revamped and constellation lines as well as Deep Sky objects have been added.

 

This task is about adding more objects. Check out Marble's source code (http://marble.kde.org/sources.php will tell you how) and open the file

marble/data/stars/dso.dat

Then add Rectaszension and Declination for the following objects:

  • Large Magellanic Cloud (http://en.wikipedia.org/wiki/Large_Magellanic_Cloud)
  • Small Magellanic Cloud (http://en.wikipedia.org/wiki/Small_Magellanic_Cloud)
  • Double Cluster (http://en.wikipedia.org/wiki/Double_Cluster)
  • Beehive Cluster (http://en.wikipedia.org/wiki/Beehive_Cluster)

 

Please also add the lines for some constellations to the file

marble/data/stars/constellations.dat

namely the following ones:

  • Centaurus ( with exactly these constellation lines: http://de.wikipedia.org/w/index.php?title=Datei:Centaurus_constellation_map.png&filetimestamp=20041212180049 )
  • Triangulum Australe ( with exactly these constellation lines: http://en.wikipedia.org/wiki/File:Triangulum_Australe_IAU.svg )
  • Grus ( with exactly these constellation lines: http://de.wikipedia.org/w/index.php?title=Datei:Grus_constellation_map.svg&filetimestamp=20100709023657 )
  • Columba ( with exactly these constellation lines: http://en.wikipedia.org/wiki/File:Columba_IAU.svg )

Creating the constellation lines works like this: you look up the stars one by one that are part of the lines: In Centaurus you could start of with the Star named Toliman which is "Alpha Centauri" or short "Alp Cen". Look up "Alp Cen" in the file

marble/tools/stars/catalog.dat

After some search it turns out there is no "Alp Cen" but "Alp1Cen" and "Alp2Cen" because Alpha Centauri is a double star. We take the brighter component (with the lower magnitude number which is +0.71 in this case). And we identify the first number in the catalog line which is "5459". The number "5459" is the number we need to enter into the constellations.dat filel Then we continue to do the same with the next star in the line: "Beta Centauri" ("Bet Cen") and find that the number at the start of the catalog line is 5267. etc. An index number "-1" is used to start a new line string.