The revolution time of the asteroid 54 Alexandra is about 7,3 hours. Veli-Pekka Hentunen and Markku Nissinen measured five hours from this 7,3 hours revolution time 21.-22.1.2007 in Taurus Hill Observatory. The weather was clear and the temperature was about -15 celcius degrees. The R -filter and 120 sec. exposures were used for this measurement. The comparison stars were GSC1793-1602 (C1) and GSC1793-0462 (C2).
