It was discovered by Franck Marchis of UC Berkeley, and Pascal Descamps, Daniel Hestroffer, and Jérôme Berthier of the Observatoire de Paris, France, using the Yepun telescope of the European Southern Observatory (ESO) in Chile.

Marchis, the project leader, was waiting for the completion of the image acquisition programme before starting to process the data.

The moon is named after Remus, twin of the mythological founder of Rome, one of the children of Rhea Silvia raised by a wolf.

Thus it is likely that both Remus and Romulus are smaller rubble piles which accreted in orbit around the main body from debris of the same collision.

[3] From Remus's surface, Sylvia appears huge, taking up an angular region roughly 30°×18° across, while Romulus's apparent size varies between 1.6° and 0.5° across.