540 Rosamunde is an S-type asteroid<sup>https://web.archive.org/web/20061201092811/http://www.psi.edu/pds/resource/taxonomy.html</sup> belonging to the Flora family in the Main Belt. Its diameter is about 19 km and it has an albedo of 0.243 <sup>https://web.archive.org/web/20070119015129/http://www.psi.edu/pds/resource/imps.html</sup>. Its rotation period is 9.336 hours<sup>https://archive.today/20060614093519/http://www.psi.edu/pds/archive/lc.html</sup>.
Rosamunde is named for a character in a play of the same title for which Franz Schubert wrote incidental music.