20936 Nemrut Dagi

Upon discovery, this minor planet was designated 4835 T-1. The survey designation means that it was the 4835th object discovered in the "T-1" series, which 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 (also known as the 48-inch Schmidt 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 several thousand asteroid discoveries.[8]

It was named after the a dormant volcano Nemrut (Nemrut Dağı) 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 asteroid's name was proposed by German astronomer Joachim Schubart,[1] and its official naming citation was published by the Minor Planet Center on 6 April 2012 (M.P.C. 79103).[9]

In December 2015, a rotational lightcurve of Nemrut Dagi was obtained by American astronomer Brian Warner at his CS3–Palmer Divide Station (U82) in California. Lightcurve analysis gave a well-defined rotation period of 3.2754±0.0005 hours with a low brightness variation of 0.08±0.01 magnitude (U=3), indicating that the body has a rather spheroidal shape.[6]

This result supersedes previous observations. Warner obtained similar periods of 3.233±0.002 and an amplitude of 0.05±0.01 (November 2007, revised),[6] 3.321±0.002 hours and 0.15±0.02 (February 2011),[10] and 5.697±0.002 hours and 0.15±0.02 (November 2007),[11] with a quality code of U=2, 2 and 0, respectively.[7] The asteroid was also observed by American astronomer Brian A. Skiff during the Near-Earth Asteroid Photometric Survey (NEAPS) at Lowell Observatory, who obtained a period of 3.233±0.002 in February 2011, which he directly reported to the LCBD (U=2).[lower-alpha 1] Additional observations by NEAPS were published in 2019, and gave a concurring period of 3.283±0.007, 3.285±0.004, and 3.274±0.003 (U=2+,2+,2+).[12] In May 2019, observations by Robert Stephens at CS3 (U81) determined a period of 3.328±0.002 (U=2).[13]^: 453

According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid has a mean-diameter of 3.21±0.50 km, 3.51±0.66 km, and 3.57±0.19 km with an exceptionally high albedo of 0.31±0.11, 0.43±0.14, and 0.460±0.078, respectively.[3][4][5][14] A high albedo of 0.30 or more is typically seen among the bright E-type asteroids that are thought to be composed of enstatite, a mineral which is rich in Magnesium sulfite (MgS0₃). The Collaborative Asteroid Lightcurve Link assumed a standard albedo for a common S-type asteroid of 0.20, and calculates a larger diameter of 5.3 kilometers based on an absolute magnitude of 13.8.[7]