Google Summer of Code 2015 – Week One : The Joy Of The First Paycheck!

This is the first week of Google Summer of Code. The coding period began officially on the 25th of May. And I received my first paycheck of $500 from Google! I am already learning new things everyday, which makes this project very exciting!

What I have done till now is collect constellation artwork used in Stellarium, and complied a list of 3 stars for each constellation which would be used to position the constellation image in the sky map. I started coding and have written the ConstellationArt class declaration. Earlier I had included a Q_PROPERTY to make constellations fade in and out, but I was told that this would be difficult to achieve since KStars doesn’t use OpenGL. In any case, I think getting the constellations to display correctly in the sky is more important than making them fade. That could always be done at a later point of time.

Stellarium uses the Hipparcos catalog numbers, while KStars uses the Henry Draper Index. So I converted Hipparcos numbers to Henry Draper numbers using a cross-index file. I referred to SIMBAD for a few individual cases of double stars. I randomly chose the Henry Draper number of one of the children in the double star. This would technically cause the constellation image to be ‘slightly’ misaligned, but constellations are a figment of imagination, and hence the misalignment would be pardonable.

New stuff I learnt this week: I read about different star catalogs including the Hipparcos catalog, Henry Draper catalog, Smithsonian Astrophysical Observatory Star Catalog (SAO numbers). I also ended up reading on Flamsteed designations, and Bayer designations of a star.

What’s next? I need to understand how the draw() function works in KStars, and how it would be used to draw a constellation image. I have written some code till now that opens up the ‘constellationart.txt’ file and read the values for each of the 3 important stars in a constellation. The values include x1,y1,hd1,x2,y2,hd2,x3,y3,hd3, constellation abbreviation and image file name. These values will now be populated into an array of 88 elements, each of which would be a structure.

I will describe more on how I plan to solve the problem in future posts.