Born Thonne-la-Long, (Meuse), France, 1751
In 1783, French astronomer Joseph d’Agelet was cataloging stars when one (WY Sagittae) disappeared from view. For more than a century d’Agelet’s Star perplexed observers. Then, in the 1950s, Lick Observatory astronomers in California located a faint star at the same coordinates. D’Agelet had happened to catch a nova.