3204 Lindgren

3204 Lindgren, provisional designation 1978 RH, is a carbonaceous background asteroid from the outer regions of the asteroid belt, approximately 20 kilometers (12 miles) 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.^[1] The B-type asteroid has a rotation period of 5.6 hours.^[8] It was named after Swedish writer Astrid Lindgren.^[1]

3204 Lindgren

Discovery[1]
Discovered by	N. Chernykh
Discovery site	Crimean Astrophysical Obs.
Discovery date	1 September 1978
Designations
MPC designation	(3204) Lindgren
Named after	Astrid Lindgren[1] (Swedish writer)
Alternative designations	1978 RH · 1980 CQ 1980 DM
Minor planet category	main-belt[1][2] · (outer) background[3]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	39.06 yr (14,266 d)
Aphelion	4.0411 AU
Perihelion	2.2764 AU
Semi-major axis	3.1588 AU
Eccentricity	0.2793
Orbital period (sidereal)	5.61 yr (2,051 d)
Mean anomaly	327.09°
Mean motion	0° 10m 32.16s / day
Inclination	2.0630°
Longitude of ascending node	108.70°
Argument of perihelion	298.30°
Physical characteristics
Mean diameter	18.95±0.80 km[4] 19.596±0.248 km[5][6] 20.2±2.0 km[7] 20.21 km (calculated)[8] 21±2 km[9]
Synodic rotation period	5.614±0.0047 h[10] 5.618±0.0047 h[10]
Geometric albedo	0.05±0.01[9] 0.057 (assumed)[8] 0.06±0.01[7] 0.0606±0.0151[6] 0.063±0.007[5] 0.065±0.006[4]
Spectral type	B (S3OS2)[11] C (assumed)[8]
Absolute magnitude (H)	12.10[7] 12.170±0.001 (R)[10] 12.20[2][4][6][8][9] 12.35±0.23[12] 12.582±0.001 (S)[10]

Orbit and classification

Lindgren is a non-family asteroid from the main belt's background population.^[3] 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.^[2] The body's observation arc begins with its official discovery observation at Nauchnij in 1978.^[1]

Physical characteristics

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).^[11] It is also an assumed C-type asteroid.^[8]

Rotation period

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 (U=2/2).^[10]

Diameter and albedo

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.^{[4][5][6][7][9]}

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.^[8]

Naming

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.^[1] The official naming citation was published by the Minor Planet Center on 2 April 1988 (M.P.C. 12971).^[13]