Observations carried out during 2011 January, February, and early March allowed us to determine the synodic periods of main-belt asteroids 1318 Nerina, 4175 Billbaum, and 5168 Jenner. For 1318 Nerina we derived a period of 2.528 ± 0.001 h, very much in line with a previous estimate. For 4175 Billbaum, a period of 2.908 ± 0.001 h with an amplitude of 0.18 mag was found. 5168 Jenner also showed a
... [Show full abstract] rapid rotational period of 3.258 ± 0.001 h, amplitude 0.39 mag.