1541 Estonia
1541 Estonia, provisional designation , is an asteroid from the central regions of the asteroid belt, approximately 21 kilometers in diameter. It was discovered on 12 February 1939, by astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory near Turku, Finland. The asteroid was named after the Baltic country of Estonia. Orbit and classification. "Estonia" is a non-family asteroid from the main belt's background population. It orbits the Sun in the central main belt at a distance of 2.6–3.0 AU once every 4 years and 7 months (1,683 days). Its orbit has an eccentricity of 0.07 and an  inclination of 5° with respect to the ecliptic. The asteroid was first identified as at the Simeiz Observatory in April 1916. The body's observation arc begins with its identification as at Yerkes Observatory in November 1923, more than 15 years prior to its official discovery observation at Turku. Physical characteristics. In the SMASS classification, "Estonia" is a Xc-subtype that transitions from the X-type to the carbonaceous C-type asteroids. Rotation period. In November 2015, a rotational lightcurve of "Estonia" was obtained from photometric observations by French amateur astronomer René Roy. Lightcurve analysis gave a rotation period  of 10.1 hours with a brightness amplitude of 0.13 magnitude (). Diameter and albedo. According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, "Estonia" measures between 19.53 and 24.542 kilometers in diameter and its surface has an albedo between 0.0976 and 0.140. The "Collaborative Asteroid Lightcurve Link" derives an albedo of 0.1314 and a diameter of 20.15 kilometers based on an absolute magnitude of 11.3. Naming. This minor planet was named after the Baltic country of Estonia, just south of the Gulf of Finland and Finland itself . The two countries are inhabited by related Balto-Finnic peoples. Estonia gained independence from Soviet rule in 1991. The official was published by the Minor Planet Center in January 1956 ().