He was born in Moscow but his father's ancestors are from a Serbian town called Belo Polje.

Belopolsky was known for his fine instrument making, and in 1900 he built a device for measuring the Doppler shift of spectra.

He pioneered the use of optical Doppler shift to measure the rotational rates of distant objects.

[2] He was a good friend of Oskar Backlund, and when the latter died in 1916, he succeeded him as director of Pulkovo Observatory.

The crater Belopol'skiy on the Moon, the asteroid 1004 Belopolskya and an award of the Russian Academy of Sciences are named after him.