1607 Mavis, provisional designation 1950 RA, is a stony asteroid from the middle region of the asteroid belt, approximately 12 kilometers in diameter. It was discovered on 3 September 1950, by South African astronomer Ernest Johnson at Johannesburg Observatory in South Africa.
Mavis is a stony S-type asteroid that orbits the Sun at a distance of 1.8–3.3 AU once every 4 years and 1 month (1,487 days). Its orbit has an eccentricity of 0.31 and an inclination of 9° with respect to the ecliptic. The asteroid's observation arc begins with its official discovery observations, as the two previous identifications, A903 BH and 1934 VQ, made at Heidelberg and Simeiz in 1903 and 1934, respectively, remained unused.
In September 2007, Australian astronomers Collin Bembrick and Julian Oeya independently obtained a rotational light-curve of Mavis. The well-defined light-curves gave a rotation period of 6.1339 and 6.1508 hours with a brightness variation of 0.50 and 0.53 magnitude, respectively (U=3/3).
According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Mavis measures between 11.57 and 14.91 kilometers in diameter and its surface has an albedo between 0.189 and 0.31. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.3320 and a diameter of 12.10 kilometers based on an absolute magnitude of 11.4.
This minor planet was named in honor of the Mavis Bruwer, wife of astronomer Jacobus Albertus Bruwer, who was an astronomer at Johannesburg Observatory, and after whom 1811 Bruwer was named. Naming citation was published before November 1977 (M.P.C. 3931).