The Second Sun
The Second Sun is a story written by Kikuna Matata and illustrated by beili. It ran in Special Issue 9 at http://s2b2.livejournal.com/271056.html, and is mirrored at http://www.shousetsubangbang.com/mirror/the-second-sun/.
From fail-fandomanon.dreamwidth.org: "Set in the C19th - Isabel, disguised as a young man, travels Europe studying astronomy and trying to avoid discovery."
- pinboard.in: "Original f/f. In 1811, astronomer Isabel travels Europe disguised as a young man, carousing with poets and scientists, dancing with nobility. Gorgeous use of language and such a beautiful slow reveal of the characters and Isabel's story - just stunningly well written."