The astronomy collection is housed in the Baker-Berry Library, specifically in Berry Level 4.
Bound volumes of journals are shelved alphabetically by title and books in astronomy are shelved by Library of Congress call number in the Baker-Berry stacks. Astronomy books are classed in the QB's.
Did you know that you can request items that the library doesn't own?
If you're a Dartmouth student, you can get a free library card to the the public Howe library in Hanover!
Although the Dartmouth Libraries have a solid amount of books for leisure reading (try searching for some of your favorite titles in the catalog - see what you find!), public libraries specialize in these kinds of titles, including audiobook and eBook formats. Sign up for a library card to get access to their collections.