Euclid Ecliptic Survey asteroid Prot

Some asteroids show multimodality in the MCMC search, indicating period aliases; in these cases, we report all aliases and their likelihoods. We validate our pipeline by comparing our fitted periods with 48 published periods, including period harmonics. We find that 44% of our periods are within 1% of those published and 98% are within 15%, and we establish that with 98% confidence the best solution can be found among the first three aliases.

All reliable periods reported are in agreement with our current understanding of the spin-period distribution for asteroids. We find 16 periods below the spin barrier of 2.2h with absolute magnitudes below 19, and thus candidate super-fast rotators. We provide lightcurves for all 2321 objects observed and 889 high-quality periods in an open-access catalogue.

The asteroids with reported periods include five Mars crossers, four Cybeles, four Hildas, three Hungarias, and 877 asteroids in other regions of the Main Belt. Our results represent the first batch of spin periods extracted from Euclid lightcurves and include the first-ever period measurements for 93% of the objects.