M91
... that although Charles Messier discovered the galaxy M91 in 1781, it was added to his catalogue only two centuries later?
... that although <a href="./Charles_Messier" id="mwA2U" rel="mw:WikiLink" title="Charles Messier">Charles Messier</a> discovered the <a href="./Galaxy" id="mwA2Y" rel="mw:WikiLink" title="Galaxy">galaxy</a> <b id="mwA2c"><a href="./Messier_91" id="mwA2g" rel="mw:WikiLink" title="Messier 91">M91</a></b> in 1781, it was added to <a class="mw-redirect" href="./Messier_catalogue" id="mwA2k" rel="mw:WikiLink" title="Messier catalogue">his catalogue</a> only two centuries later?