20936 Nemrut Dagi


20936 Nemrut Dagi, provisional designation, is a stony asteroid from the innermost regions of the asteroid belt, approximately 3.5 kilometers in diameter. It was discovered on 13 May 1971, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at the Palomar Observatory in California, United States.

Orbit and classification

Nemrut Dagi as a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the inner main-belt at a distance of 1.7–2.0 AU once every 2 years and 6 months. Its orbit has an eccentricity of 0.10 and an inclination of 19° with respect to the ecliptic.
Due to its perihelion of less than 1.668 AU, Nemrut Dagi is classified as a Mars-crosser by the Lightcurve Data Base, while in JPL's data base, which requires a perihelion of less than 1.666 AU, the asteroid is simply an inner main-belt asteroid.
The asteroid's observation arc begins 18 years prior to its official discovery observation, with its identification at Palomar Observatory in February 1953.

Survey designation

The survey designation "T-1" stands for the first Palomar–Leiden Trojan survey, named after the fruitful collaboration of the Palomar and Leiden Observatory in the 1960s and 1970s. Gehrels used Palomar's Samuel Oschin telescope, and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of :Category:Discoveries by the Palomar–Leiden survey|several thousand asteroid discoveries.

Physical characteristics

Lightcurves

In December 2015, a rotational lightcurve of Nemrut Dagi was obtained by American astronomer Brian Warner at his CS3–Palmer Divide Station in California. Lightcurve analysis gave a well-defined rotation period of hours with a brightness variation of 0.08 magnitude, indicating that the body has a rather spheroidal shape.
The results supersede previous observations made by Warner and by Brian A. Skiff, which gave similar results.

Diameter and albedo

According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid has an exceptionally high albedo of 0.46 and a diameter of 3.6 kilometers, while the Collaborative Asteroid Lightcurve Link assumed a standard albedo for stony asteroids of 0.20, and correspondingly, calculates a much larger diameter of 5.3 kilometers based on an absolute magnitude of 13.8.

Naming

This minor planet was named after the a dormant volcano Nemrut in Turkey. It is the most western volcano of a group of volcanoes near Lake Van in Eastern Anatolia. The volcano is named after King Nimrod who is said to have ruled this area in about 2100 BC. The approved naming citation was published by the Minor Planet Center on 6 April 2012.