On the extrasolar/data plots directory of the Motherlode :
http://www.celestiamotherlode.net/catalog/dataplots.php
there's a recent addon called "Association Cyg OB 2" from Miguel (third addon in the list). I was thinking about emailing the author, but I think it's a better idea to tell publicly what is wrong here, as an example of what may hurt Celestia. Many users may believe it's an accurate or safe addon, while it isn't. Of course, if I make a mistake myself here, please tell me and I'll retract with an apology.
Firstly, the readme file coming with the addon is in spanish only (or catalan, or whatever), and there's none in English. In the interest of all, there should be an English readme as well. Visibly, the author didn't care about communication. To me, this is a wrong indication about the validity of the addon itself.
Secondly, there are many double star systems in this addon, which are supposed to be realistic (it's not supposed to be some SF addon). Well, if you visit many of those double star systems, they just doesn't make any sense at all. Most of the companion stars are way too close from each other, they can't be stable or even be visible from Earth. And they don't move around their barycenter properly. How am I supposed to interpret this star addon ?
So, IMHO, this addon shouldn't be on the Motherlode, in a realistic directory.
![Evil or Very Mad :evil:](./images/smilies/icon_evil.gif)
I'm sorry, but we should be more carefull before sending any realistic addon to the public, and the guys at the Motherlode should be more carefull when it comes to select the realistic addons. This is about science, isn't ?
Now, I apologise if I sounded rude and clumsy. English isn't my first language, but at least, I'm trying to express myself in English so everybody could understand me here.