4923 Clarke, provisional designation 1981 EO27, is a stony background asteroid from the inner regions of the asteroid belt, approximately 3.5 kilometers (2.2 miles) in diameter. It was discovered on 2 March 1981, by American astronomer Schelte Bus at the Siding Spring Observatory in Australia.[1] The spheroidal S-type asteroid has a rotation period of 3.14 hours.[6] It was named after British science fiction writer Arthur C. Clarke.[1] On the same night, Schelte Bus also discovered 5020 Asimov.
The asteroid was first observed as 1972 NJatCrimea–Nauchnij in July 1972. The body's observation arc begins at the Siding Spring Observatory two weeks prior to its official discovery observation on 12 February 1981.[1]
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Clarke measures between 3.367 and 3.532 kilometers in diameter and its surface has an albedo between 0.3259 and 0.366.[4][5] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and calculates a diameter of 4.10 kilometers based on an absolute magnitude of 14.3.[6]
^ abcAznar Macias, Amadeo (January 2017). "Lightcurve Analysis from APT Observatory Group for Nine Mainbelt Asteroids: 2016 July-September. Rotation Period and Physical Parameters". The Minor Planet Bulletin. 44 (1): 60–63. Bibcode:2017MPBu...44...60A. ISSN1052-8091.
^ abcWaszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. S2CID8342929.
^Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID53493339.