| Minorplanet: | yes |
| 3204 Lindgren | |
| Background: |
|
| Discovery Ref: |   |
| Discovered: | 1 September 1978 |
| Mpc Name: | (3204) Lindgren |
| Alt Names: | 1978 RH1980 CQ 1980 DM |
| Named After: | Astrid Lindgren  |
| Mp Category: | main-belt  background  |
| Orbit Ref: |   |
| Epoch: | 23 March 2018 (JD 2458200.5) |
| Uncertainty: | 0 |
| Observation Arc: | 39.06 yr (14,266 d) |
| Perihelion: | 2.2764 AU |
| Semimajor: | 3.1588 AU |
| Eccentricity: | 0.2793 |
| Period: | 5.61 yr (2,051 d) |
| Mean Motion: | / day |
| Inclination: | 2.0630° |
| Asc Node: | 108.70° |
| Arg Peri: | 298.30° |
| Mean Diameter: | 20.21 km |
| Rotation: | |
| Albedo: | |
| Abs Magnitude: | 12.10 12.20 |
3204 Lindgren, provisional designation, is a carbonaceous background asteroid from the outer regions of the asteroid belt, approximately 20km (10miles) 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 2.3–4.0 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 2° 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 (1907–2002), 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 .