after looking through the thread I can't find a reason for why everyone assumes the things floating in demise's realm and the moon in majora's mask are considered stars.
I remember people talking about the color of the two "stars" in question and relating them back to our own sun, but I see no reason why this would be the case. Just because the object in question produces white light doesn't necessarily make it a star. While it's been well over a year since i've done anything more complicated then basic algebra, but allow this amature astronomer to bore you with some dumb science stuff.
I assume that when people are talking about the color of the star in majora's mask and skyward sword they are talking about the
Apparent Magnitude of these two objects, except this is very inaccurate as for a number of reasons, one being your using the human eye a very imprecise measuring tool, another being that your using your(link's) current locations which leads to a wide variety of results depending on where someone is positioned, also this only really works at night.
If you want to find out the actual color of the star your would need to find the color of the wave lengths the star produces on the electro magnetic specturm then figure out the black body radiation as a function of wavelength using after that you would use
Wien's Law to find the temperature of the star. Finally you would take the temperature found using Wein's law and place it on the
Hertzsprung―Russell diagram to find the size of the star. Our own sun is a type G star with a temperature of 5,800K.
I made a mentioned earlier about the electromagnetic specturm, using the color of the star in question you could use
Absolute Magnitude to calculate the luminosity of a star assuming it was 32.6 light years(10 parces) away from you and then use the
stellar luminosity calculator to find the size.
Once you find one piece of information about a star someone can pretty reliably math out the rest. Just one problem though, I have no idea how you would find any information about either object in majora's mask or skyward sword and I know someone is going to say something like of course Eiji Aonuma and Tayaka Imamura wanted them to be stars I just don't feel comfortable calling something a star when for all I know it could just be a giant lightbulb.