483P/PanSTARRS

483P/PanSTARRS (provisional designation P/2016 J1) is a pair of active main-belt asteroids that split apart from each other in early 2010. The brightest and largest component of the pair, P/2016 J1-A, was discovered first by the Pan-STARRS 1 survey at Haleakalā Observatory on 5 May 2016. Follow-up observations by the Canada-France-Hawaii Telescope at Mauna Kea Observatory discovered the second component, P/2016 J1-B, on 6 May 2016. Both asteroids are smaller than 1 km in diameter, with P/2016 J1-A being roughly 0.6 km in diameter and P/2016 J1-B being roughly 0.3 km in diameter. The two components recurrently exhibit cometary activity as they approach the Sun near perihelion, suggesting that their activity is driven by sublimation of volatile compounds such as water.

Asteroid family
In 2018, an orbit analysis by Hsieh et al. found that both components of P/2016 J1 are related to the Theobalda asteroid family of C-, F-, and X-type asteroids. The Theobalda family likely originated as fragments from an impact event that shattered a 78 ± 9 km-diameter parent body $<0.62 km$ million years ago. Another ice-sublimating active asteroid, 427P/ATLAS (P/2017 S5), was also identified to be part the Theobalda family, suggesting that some members of this family were able to retain subsurface water ice since the collision that formed them.