CCD photometry and new models of 5 minor planets

We present new R filtered CCD observations of 5 faint and moderately faint asteroids carried out between October, 1998 and January, 1999. The achieved accuracy is between 0.01-0.03 mag, depending mainly on the target brightne ss. The obtained sinodic periods and amplitudes: 683 Lanzia - 4(h).6 +/- 0( h).2, 0.13 mag; 725 Amanda > 3(h).0, greater than or equal to 0.40 mag; 852 Wladilena - 4(h).62 +/- 0(h).01; 0.32 mag (December, 1998) and 0.27 mag (J anuary; 1999); 1627 Ivar - 4(h).80 +/- 0(h).01; 0.77 mag (December, 1998) a nd 0.92 mag (January. 1999). The Near Earth Object 1998 PG unambiguously sh owed doubly-periodic lightcurve, suggesting the possibility of a relatively fast precession (P-1 = 1(h).3: P-2 = 5(h).3). Collecting all data from the literature, we determined new models for 3 min or planets. The resulting spin vectors and triaxial ellipsoids hare been ca lculated by an amplitude-method. Sidereal periods and senses of rotation we re calculated for two asteroids (683 and 1627) by a modified epoch-method. The results are: 683 - lambda(P) 15/195 +/- 25 degrees, beta(P) = 52 +/- 15 degrees; a/b = 1.15 +/- 0.05, b/c = 1.05 +/- 0.05, P-sid = 0(d).1964156 +/ - 0(d).0000001; retrograde; 852 - lambda(P) = 30/210 +/- 200, beta(P) = 30 +/- 10 degrees, a/b = 2.3 =/- 0.3, b/c = 1.2 +/- 0.2; 1627 - lambda(P) = 14 5/325 =/- 8 degrees, beta(P) = 34 +/- 6 degrees, a/b = 2.0 +/- 0.1, b/c = 1 .09 +/- 0.05, P-sid = 0(d).1999154 +/- 0(d).0000003; retrograde. The obtain ed shape of: 1627 is in good agreement with radar images by Ostro et al. (1 990).