How does one pronounce $a \odot b$?

Question

I have seen authors use $\star$, $\ast$, $\cdot$ and $\odot$ to represent arbitrary binary operations on sets. I'm wondering, what is the standard way to read or pronounce something like $a \star b$? How would you read $a \odot b$?

Answer 1

Usually, when I write such an operator into a problem, I use some variant of an asterisk or star (often a circled asterisk), reading it as "star" in my head. If I'm not using some sort of star, I usually use a circled or boxed X-type symbol and read it as "cross" in my head.

Answer 2

I try to read from the context what it's supposed to mean. Most of the time I can extract how it's pronounced by just looking at the preceding text.

Without context I read $\odot$ as tropical multiplication and $\star$ as convolution (of some kind), but of course they can represent some other binary operation just as well. For $\cdot$ I could use either dot or times and $*$ could be times or star, I guess.

But most of the time there is a context, isn't it? If not, then my main priority would be to try and find the context.

Answer 3

I suggest "sun" for $\odot$ (the standard astronomical symbol).