1621 Druzhba

1621 Druzhba, provisional designation 1926 TM, is a stony asteroid and slow rotator from the inner regions of the asteroid belt, about 9 kilometers in diameter. It was discovered by Russian astronomer Sergey Belyavsky at the Crimean Simeiz Observatory on 1 October 1926.

The S-type asteroid is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,216 days). Its orbit shows an eccentricity of 0.12 and is tilted by 3 degrees to the plane of the ecliptic. It has an albedo between 0.2 and 0.3, based on the surveys carried out by IRAS, Akari, and WISE/NEOWISE.

Photometric observations made in 2006 at the Oakley Observatory in Terre Haute, Indiana, found a light curve period of 7001479000000000000♠47.9±0.5 hours, with variation in brightness of less than one magnitude. In 2010, observations were made at the Goat Mountain Astronomical Research Station in Rancho Cucamonga, California, gave a period estimate of 47.9 hours, although this may be a half rotation period instead (99.2 hours). The long rotation period makes accurate estimates more difficult to obtain, so further data is needed to reduce the margin of error.