11066 Sigurd
11066 Sigurd, provisional designation , is a stony, rare-type asteroid and elongated contact binary, classified as near-Earth object of the Apollo group of asteroids, approximately 2.5 kilometers in diameter. It was discovered on 9 February 1992 by American astronomer couple Carolyn and Eugene Shoemaker at Palomar Observatory, California, and named after Sigurd, a hero from Norse mythology. Orbit and classification. "Sigurd" orbits the Sun in the inner main-belt at a distance of 0.9–1.9 AU once every 1 years and 8 months (600 days). Its orbit has an eccentricity of 0.38 and an inclination of 37°  with respect to the ecliptic. A first precovery was taken at the Australian Siding Spring Observatory in 1978, and it was identified as at Palomar in 1987. Both observations remained unused. The body's observation arc begins with its official discovery observation at Palomar in 1992. It has an "Earth minimum orbital intersection distance" of , which corresponds to 46.1 lunar distances. Physical characteristics. In the SMASS taxonomy, "Sigurd" is a relatively rare K-type asteroid, which fall into the broader stony S-complex. It has also been grouped into the common S-type asteroid. The ExploreNEOs Warm Spitzer program, using  the NASA Infrared Telescope Facility on Mauna Kea Observatory in Hawaii, classifies "Sigurd" as a Sr-type, which transitions to the R-type asteroids. Contact binary. Radiometric observations at Arecibo Observatory revealed that "Sigurd" is a contact binary, composed of two lobes in contact with each other. The more or less ellipsoidal lobes are elongated and joined on their long axis. The body has an axial tilt of 50° to 130°. The observing astronomers also note, that more than 10% of all larger (> 200 meters) near-Earth objects observed by radar are such contact binaries. Photometry. Rotational  lightcurves obtained from photometric observations by Petr Pravec, Brian Warner and by a group of German and Ukrainian astronomers, gave a well-defined rotation period of 8.4958 to 8.51 hours. The analysis of the constructed lightcurves also gave a high brightness amplitude between 0.97 and 1.15 magnitude, which is indicative that "Sigurd" has a non-spheroidal shape (). Diameter and albedo. According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, "Sigurd" measures between 2.10 and 2.778 kilometers in diameter and its surface has an albedo of 0.190 and 0.29, respectively. Observations  by the ExploreNEOs survey give a higher albedo of 0.38. The "Collaborative Asteroid Lightcurve Link" assumes an albedo of 0.18 and calculates a diameter of 2.86 kilometers with an absolute magnitude of 15.2, while radiometric observations of "Sigurd" gave an maximum dimensions of 4.2 kilometers. Naming. This minor planet was named after Sigurd, a legendary hero in Norse mythology. In the Völsunga saga, Sigurd rides through a ring of fire to awaken the shieldmaiden Brynhild (), and later dies in a fight with Odin (). Sigurd is also known as the dragon-slayer Siegfried in the German poem "The Song of the  Nibelungs". The approved naming citation was published by the Minor Planet Center on 23 May 2000 ().