Thanks for this post Marco. Unfortunately I was unable to reproduce your beautiful first plot. I get the following error: The front end encountered an error while processing a "NotebookPredictions" packet. I'm running Mathematica 11.0.1 for Linux x86 (64-bit) (September 21, 2016).
One other thing that you may want to mention in your post (or maybe think about lowering the number of stars?): it took over 6 hours to download the data for the 10000 stars (60000 data items). It was not due to a slow connection on my end. I wonder if Wolfram purposely slows down data for large requests or if the request is coming from someone (like me) who only has the Home Edition of Mathematica? The data started coming down fairly fast but got slower and slower. By the end the "downloading" box was counting 1 data item about every 3 seconds!
Thanks again,
Joe