4897 Tomhamilton

4897 Tomhamilton, provisional designation, is a stony asteroid from the outer region of the asteroid belt, approximately 14 kilometers in diameter. It was discovered on 22 August 1987, by American astronomer Eleanor Helin at Palomar Observatory, California. It was later named after American writer Thomas William Hamilton, an author of astronomy books and participant in the Apollo program.

Classification and orbit
Tomhamilton orbits the Sun in the outer main-belt at a distance of 2.7–3.4 AU once every 5 years and 4 months (1,953 days). Its orbit has an eccentricity of 0.12 and an inclination of 11° with respect to the ecliptic.

In August 1950, a first precovery was taken at Palomar, extending the asteroid's observation arc by 37 years prior to its official discovery observation. It had also been previously identified as and  at Crimea–Nauchnij.

On 11 January 2011, it was at opposition (coinciding with Hamilton's 72nd birthday) at a distance of 2.476 AU. Given the moderately elliptical orbit, this asteroid can on rare occasions reach an apparent magnitude from Earth of about 10.9.

Naming
This minor planet was named after Thomas William Hamilton, an American (born San Francisco, January 11, 1939) who had worked on the Apollo program, determining fuel requirements and radar accuracy requirements for lunar orbit rendezvous. He later worked as an astronomy educator and planetarium director, and as an author on astronomical topics, as well as of time travel and science fiction novels. Hamilton and Helin were acquainted, as he had interviewed her at an astronomical conference for a cable television show he was producing at the time. The official was published by the Minor Planet Center on 4 October 2009 (M.P.C. 67215).

Diameter and albedo
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Tomhamilton measures 13.7 kilometers in diameter and its surface has an albedo of 0.215, which indicates that it of a stony rather than of a carbonaceous composition.

Lightcurve
As of 2017, no rotational lightcurve of Tomhamilton has been obtained from photometric observations. It rotation period, poles and shape remain unknown.