Visibility II / V
2091 Sampo (1941 HO, 1931 MG, 1938 UF1,1951 GA1,1952 LB, 1956 EP, 1971 BH1,1978 NB, A924 BB). Filmed on a DS weekend on Sunday. Finland 100 The target of our project 22. The asteroid on the outer edge of the main zone, discovered by Yrjö Väisälä on May 26, 1941 in Iso-Heikkilä, Turku. The size of the asteroid is 23.02km and the spin time is 71.34h / r, spectral class S. Belongs to the Eos (221 Eos) asteroid family, all with similar orbits suggesting a previous collision .Asteroid families https://en.wikipedia.org/wiki/Asteroid_family .
1Picture. Appears in motion, difficult to distinguish because close to the star.
2Picture.first image, measured 23: 25: 55UT 6h35m57.29s + 16d10'22.5 "16.05mag, Horizon 23: 26UT 6h35m57.34s + 16d10'21.8" 15.99mag.
3Picture.last picture, measured 23: 44: 54UT 6h35m58.16s + 16d10'24.0 "15.95mag., Horizon 23: 45UT 6h35m58.11s + 16d10'21.2" 15.99mag .Brightness used for calibration TYC 1329-979-1 v.11.23mag stars. The measurement was very difficult when disturbed by a nearby star of almost the same brightness (two stars). The star and asteroid partially merged in a few images. The measurement was aided by the fact that the weather was good, Average residual 0.4 arcsec; order 4, PinPoint.