[dredmorbius]

It is true for the Earth and Sun, yes, but the amount of overfill is small.

I don't know the apparent size of the star in question here -- ah, the paper (http://arxiv.org/pdf/1312.3943v1.pdf) gives it: 46.5%. Compare that with the apparent size, or angular diameter, of the Sun as viewed from Earth: 2 degrees. About the size of your thumb at arm's length.

Your mileage may vary, but if I extend both my hands out, touch the thumbs together, and spread my thumbs and pinkies as wide as I can, that's roughly 20x wider than my thumb. Imagine that as the Sun looming in your sky.

[SiVal]

I believe the angular diameter of both sun and moon are roughly half a degree, not two degrees. You remembered the two correctly, but put two degrees in one sun instead of two suns in one degree. That's how our brains work, isn't it?

[dredmorbius]

Thanks for that.

I managed to mis-read from Wikipedia: "The angular diameter of Earth's orbit around the Sun, from a distance of one parsec, is 2″ (two arcseconds)." Somewhat lower on the page we find: "The table shows that the angular diameter of Sun, when seen from Earth is approximately 32 arcminutes (1920 arcseconds or 0.53 degrees), as illustrated above."

So, if my initial estimate of "thumb at arm's length is the size of the Sun", then my "two hands spanned" is about 4x too small ... woah. Hold your arms out at a 45° angle. That's about the size of it.

That would be ... a lot of star in the sky ...

I also should've trusted my first impression on the 0.5 degree as well. I believe I knew that. Hasty verification fouls memory.

[Dylan16807]

Interesting that your first comment explicitly stated 46 degrees but then you somehow logiced yourself out of that.