Astrometric and Photometric Studies of a Potentially Hazardous Asteroid (138971) 2001 CB21

In 2022, the telescope of the Main (Pulkovo) Astronomical Observatory of RAS obtained astrometric and photometric series of observations of a potentially dangerous asteroid (138971) 2001 CB21 during its approach to Earth. Based on the data obtained and data from the MPC website, the asteroid’s orbit was improved and the circumstances of the encounters were investigated with the Earth and Venus and an assessment was made of the influence of nongravitational effects on its motion. Based on photometric observations of the asteroid, a light curve was constructed and its axial rotation period was confirmed: R = 3.305 ± 0.002 h.