22740 Rayleigh (provisional designation1998 SX146) is a Zhongguo asteroid from the outermost region of the asteroid belt, approximately 10 kilometers (6 miles) in diameter. It was discovered on 20 September 1998, by Belgian astronomer Eric Elst at the La Silla Observatory in Chile. It is one of few asteroids located in the 2 : 1 resonance with Jupiter. The asteroid was named for English physicist and Nobel laureate Lord Rayleigh.[2]
It orbits the Sun in the outer asteroid belt at a distance of 2.5–3.9 AU once every 5 years and 10 months (2,133 days; semi-major axis of 3.24 AU). Its orbit has an eccentricity of 0.21 and an inclination of 3° with respect to the ecliptic.[1] The body's observation arc begins with its observations as 1986 SN at Klet Observatory in September 1986, or 13 years prior to its official discovery observation at La Silla.[2]
As of 2018, no rotational lightcurve of Rayleigh has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.[1][6]