Comparing image sizes of the hotter stars with the cooler stars

[James Beedy]

Homework Statement

When comparing image sizes of the hotter stars with the cooler stars, do hotter stars consistently appear larger in one image and cooler stars consistently appear smaller in the other image? Why or why not?

Homework Equations

Stellar Spectra Classification[/B]

The Attempt at a Solution

: I understand during a stellar spectra classification, [/B]
A hot star has a B-V color index close to 0 or negative, while a cool star has a B-V color index close to 2.0. Other stars are somewhere in between. The flux of energy passing through the filter tells you the magnitude (brightness) at the wavelength of the filter. It would be my opinion that it would depend on the stars color index and flux of energy that if the stars hot or cold would continually stay the same size. However, I’m not sure if this is how it really is or if I’m missing something.

 

[James Beedy]

I need help with solving the above initial question or problem. Thanks!

 

[phyzguy]

What determines the size of an object in an image? How large are stars and how far away are they? Translate this into the angular size of stars, and from the angular size, calculate the size of a star in an image. This should answer your question.

 

[haruspex]

It sounds to me as though the question is posed in some context that is missing from the thread. What images?