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Proper orbital semi-major axis, ap [au]

Figure 1. The orbital distribution of the Theobalda family members (gray dots) and locations of two main-belt comets (red dots) within the family. The black dots show the proper elements computed for the orbital clones of S5. The current membership of the Theobalda family has been obtained applying the HCM online at Asteroid Families Portal. its brightness profile is consistent with a model where dust is launched from the nucleus isotropically at a constant speed, in agreement with an assumption that the activity is driven be the sublimation of volatiles (Borysenko et al. 2018). If the above hypothesis is confirmed by future data, this would further strengthen the link between MBCs and primitive asteroid families.

This work has been supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, under the Project 176011. 3

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