Yellow and Blue Double Stars

[yeletah]

Hi

quick question,

I have noticed a pattern looking at photos of yellow and blue double stars, like Almaak and alberio.

The blue star appears to be visually smaller ?

If one of the stars of the double is blue-ish - is it usually the case it is the smaller of the pair?

if so why?

Thanks
Steve

[ronin]

Would have expected the opposite.

To get to be a blue/white star you generally need a greater amount of mass to burn hotter.

So I assume it is an optical effect, also being so far away they would all be point sourses anyway, so again more reason for it to be optical or how the eye/brain interprets things.

[wxsatuser]

If the two stars are of equal brightness, they are normally of the same spectral type.

In systems where the brightnesses are different, the fainter star is bluer if the brighter star is a gaint, and redder if the brighter is main squence.

[Pig]

I love this kind of topic

[yeletah]

Thanks,

Sound like for me, it must have been a conicidence that the blue star of a double appeared to be smaller in the doubles i have observed / from photos.