Belopolskya (minor planet designation: 1004 Belopolskya), provisional designation 1923 OS, is a dark Cybele asteroid from the outermost region of the asteroid belt, approximately 75 kilometers (47 mi) in diameter.
Belopolskya was discovered on 5 September 1923, by Russian astronomer Sergey Belyavsky at Simeiz Observatory on the Crimean peninsula.
[8] Belopolskya orbits the Sun at a distance of 3.1–3.7 AU once every 6 years and 3 months (2,292 days).
[4][5] The Collaborative Asteroid Lightcurve Link adopts the shorter diameter obtained by IRAS.
This minor planet was named in honor of Aristarkh Belopolsky (1854–1934), astrophysicist at Pulkovo Observatory, the principal astronomical observatory of the Russian Academy of Sciences, which is located south of Saint Petersburg in Russia.