3204 Lindgren, provisional designation , is a carbonaceous background asteroid from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 1 September 1978, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. The B-type asteroid has a rotation period of 5.6 hours. It was named after Swedish writer Astrid Lindgren.
Lindgren is a non-family asteroid from the main belt's background population. It orbits the Sun in the outer asteroid belt at a distance of 2.3âÂÂ4.0 AU once every 5 years and 7 months (2,051 days; semi-major axis of 3.16 AU). Its orbit has an eccentricity of 0.28 and an inclination of 2ð with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Nauchnij in 1978.
Lindgren has been characterized as a "bright" carbonaceous B-type asteroid in both the Tholen-like and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2). It is also an assumed C-type asteroid.
In August 2012, two rotational lightcurves of Lindgren were obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 5.614 and 5.618 hours with a brightness amplitude of 0.15 magnitude in the S- and R-band, respectively ().
According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Lindgren measures between 19 and 21 kilometers in diameter and its surface has an albedo between 0.05 and 0.065.
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 20.21 kilometers based on an absolute magnitude of 12.2.
This minor planet was named after Swedish writer Astrid Lindgren (1907âÂÂ2002), a recipient of the Hans Christian Andersen Award and known for her children's books such as Pippi Longstocking. The official naming citation was published by the Minor Planet Center on 2 April 1988 ().