7846 Setvák, provisional designation 1996 BJ, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered on 16 January 1996, by Czech astronomer Miloš Tichý at Kleť Observatory in South Bohemia.[9] The asteroid was named for Czech couple Stáňa and Martin Setvák.[2]
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 3.0 kilometers in diameter and its surface has a high albedo of 0.35,[4][5] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 (in accordance with the family's largest member and namesake, 8 Flora) and calculates a diameter of 2.7 kilometers.[3] A large-scale survey by Pan-STARRS (PS1) assigns an LS-type, presumably an intermediary spectral type between the common stony S-types and the rather rare and reddish L-type asteroids.[8]
This minor planet was named for Czech meteorologist Martin Setvák (born 1958), amateur astrophotographer and head of the Satellite Department of the Czech Hydrometeorological Institute, to honor his 40th birthday, as well as for his wife Stáňa Setváková (born 1967), a staff member of the Prague Planetarium.[2] The official naming citation was published by the Minor Planet Center on 11 February 1998 (M.P.C. 31298).[10]