Discovered by S. Belyavskyj MPC designation 1621 Druzhba Discovered 1 October 1926 | Discovery date 1 October 1926 Orbits Sun | |
Named after дружба – lit. friendship(in Russian) Alternative names 1926 TM · 1927 AE1931 EO · 1946 UH1949 QS1 · 1951 EK11951 ER1 · 1958 GA1979 QP4 Similar 1620 Geographos, Sun, 8 Flora, 852 Wladilena, 849 Ara | ||
1621 Druzhba, provisional designation 1926 TM, is a stony Florian asteroid and relatively slow rotator from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 1 October 1926, by Russian astronomer Sergey Belyavsky at Simeiz Observatory on the Crimean peninsula.
Druzhba is a S-type asteroid and member of the Flora family, one of the largest collisional 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 has an eccentricity of 0.12 and an inclination of 3° with respect to the ecliptic. Druzhba's observation arc begins at the discovering observatory, one week after its official discovery observation.
In August 2009, American amateur astronomer Robert D. Stephens obtained a rotational light-curve of Druzhba from photometric observations. In gave a well-defined rotation period of 99.20 hours with a change in brightness of 0.75 magnitude (U=3) A 2016-published modeled light-curve of 99.100 hours concurred with the result. This makes it a relatively slow rotator, as the vast majority of minor planets rotate every 2 to 20 hours around their axis. Druzhba's long rotation period was particularly difficulty to measure: Previously, observations by Richard Ditteon at Oakley Observatory gave a period solution of 47.9 hours (Δmag 1.0; U=1), while Polish astronomer Wiesław Wiśniewski obtained a period of only 12 hours in the late 1980s (Δmag 0.16; U=1).
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Druzhba measures between 9.08 and 12.69 kilometers in diameter, and its surface has an albedo between 0.237 and 0.312. Based on an absolute magnitude of 12.37, the Collaborative Asteroid Lightcurve Link derives a diameter of 9.05 kilometers and an albedo of 0.243 – similar to the albedo of 8 Flora, the family's largest member and namesake.
This minor planet was named Druzhba, the is a Slavic word for friendship and the name of several cities, towns and other localities in Russia, Ukraine, Bulgaria and Kazakhstan. The asteroid's name was proposed by the Institute of Theoretical Astronomy in St. Petersburg. Naming citation was published before November 1977 (M.P.C. 2740).