Starship Asterisk*

When we look at the field of stars, some stars appear bigger than others. Are some of the smallest stars actually bigger than the largest stars but appear smaller because they are farther away?

Thanks,

apod57

In images of fields of stars all the stars are essentially the same size, no size in fact, they are all point sources. We can't resolve individual stars with normal optics, though you can do it with large interferometers. (This page has some details. http://isi.ssl.berkeley.edu/research.htm)



The stars that appear larger are simply brighter, so they appear larger, this is because the light from a point source is spread out by the optics of a telescope in a characteristic pattern called the point spread function. Because the stars are brighter the outer parts of this psf are more noticable in images making the stars appear brighter/bigger.


EDIT, should have read "can't resolve" above, changed

But to answer the other part of your question, Yes. Some of the brighter stars in the image are closer to us but smaller in size than some of the less bright stars