3674 Erbisbühl

3674 Erbisbühl, provisional designation 1963 RH, is an stony asteroid and one of the largest Mars-crossers from the innermost regions of the asteroid belt, approximately 11 kilometers in diameter. It was discovered by German astronomer Cuno Hoffmeister at his Sonneberg Observatory in Eastern Germany, on 13 September 1963.

In the SMASS taxonomic scheme, the stony S-type asteroid is classified as a Sk-subtype, a transitional form to the uncommon K-type. It orbits the Sun at a distance of 1.5–3.2 AU once every 3 years and 7 months (1,324 days). Its orbit has an eccentricity of 0.38 and an inclination of 21° with respect to the ecliptic. The asteroid's observation arc starts in 1963, as no precoveries were taken and no identifications were made prior to its discovery.

A rotational light-curve for this asteroid was obtained from photometric observations made at the U.S. Antelope Hills Observatory in December 2003. It rendered a rotation period of 7001112800000000000♠11.28±0.01 hours with a brightness variation of 0.40 in magnitude (U=3). According to the survey carried out by the Japanese Akari satellite, the asteroid has a high albedo of 0.25 with a corresponding diameter of 10.3 kilometers, while the NEOWISE mission gives a diameter of 9.1 kilometers and an albedo of 0.31. TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 11.8 kilometers.

The minor planet was named for the mountain "Erbisbühl" on which the discovering Sonneberg Observatory is located (also see 1039 Sonneberga). Cuno Hoffmeister, discoverer of this asteroid and founder of the observatory, lived and worked at Erbisbühl for many decades. Naming citation was published on 2 February 1988 (M.P.C. 12809).