Rotation Period Determination for Asteroids 2232 Altaj, 3699 Milbourn 4101 Ruikou, (6787) 1991 PF15 And 8416 Okada

Photometric observations of five main-belt asteroids were conducted in order to determine their synodic rotation periods. For 2232 Altaj we found P = 8.089 ± 0.001 h, A = 0.30 ± 0.02 mag; for 3699 Milbourn we found P = 3.816 ± 0.002 h, A = 0.20 ± 0.02 mag; for 4101 Ruikou we found P = 8.098 ± 0.009 h, A = 0.07 ± 0.03 mag; for (6787) 1991 PF15 we found P = 4.645 ± 0.001 h, A = 0.80 ± 0.01 mag; for 8416 Okada we found P = 2.646 ± 0.001 h, A = 0.04 ± 0.02 mag.