Rotational properties of main belt asteroids: photoelectric and CCD observations of 15 objects

In this paper we present the results of several observational campaigns carried out during 1996 at the 1.2 m telescope of the Haute Provence Observatory (France) and at the 1.5m Danish, 0.9m Dutch, 0.6m Bochum and 0.5m telescopes of the European Southern Observatory (ESO, La Silla, Chile), in order to enlarge the available sample of know asteroid rotational periods. l of 64 single night lightcurves for 15 asteroids were obtained. The rotational periods have been determined for 12 objects, with different quality code: 424 Gratia (Psyn = 19.47 h), 440 Theodora (Psyn = 4.828 h), 446 Aeternitas (Psyn = 15.85 h), 491 Carina (Psyn = 14.87 h), 727 Nipponia (Psyn = 4.6 h), 732 Tjilaki (Psyn = 12.34 h), 783 Nora (Psyn = 34.4 h), 888 Parysatis (Psyn = 5.49 h), 1626 Sadeya (Psyn = 3.438 h), 2209 Tianjin (Psyn = 9.47 h), 2446 Lunacharsky (Psyn = 3.613 h) and 3776 Vartiovuori (Psyn = 7.7 h). For 1246 Chaka, 1507 Vaasa and 1994 Shane the complete rotational phase was not covered and for two of them it was possible to find only an indication of the rotational period.