2016 Heinemann

2016 Heinemann, provisional designation 1938 SE, is a carbonaceous Themistian asteroid from the outer regions of the asteroid belt, approximately 22 kilometers in diameter. It was discovered on 18 September 1938, by German astronomer Alfred Bohrmann at Heidelberg Observatory in southwest Germany, and later named after ARI-astronomer Karl Heinemann (1898–1970).^[2][10]

2016 Heinemann

Discovery[1]
Discovered by	A. Bohrmann
Discovery site	Heidelberg Obs.
Discovery date	18 September 1938
Designations
MPC designation	(2016) Heinemann
Named after	Karl Heinemann (1898–1970) (German astronomer)[2]
Alternative designations	1938 SE · 1927 SM 1930 DF · 1949 SB1 1971 OB1 · 1971 QP2 1972 VY · 1977 RZ7 A905 UF
Minor planet category	main-belt · Themis[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	111.34 yr (40,667 days)
Aphelion	3.7291 AU
Perihelion	2.5295 AU
Semi-major axis	3.1293 AU
Eccentricity	0.1917
Orbital period (sidereal)	5.54 yr (2,022 days)
Mean anomaly	72.570°
Mean motion	0° 10m 40.8s / day
Inclination	0.9191°
Longitude of ascending node	16.986°
Argument of perihelion	340.99°
Physical characteristics
Dimensions	21.68 km (derived)[3] 22.435±0.142 km[4] 22.718±0.080 km[5] 24.18±0.23 km[6] 25.52±1.41 km[7]
Synodic rotation period	22.96±0.01 h[8]
Geometric albedo	0.058±0.010[6] 0.0653 (derived)[3] 0.075±0.009[7] 0.0944±0.0179[5]
Spectral type	C[3]
Absolute magnitude (H)	11.4[5][7] · 11.80[6] · 11.9[1][3] · 12.01±0.33[9]

Orbit and classification

Heinemann is a member of the Themis family, a dynamical family of carbonaceous asteroids with nearly coplanar ecliptical orbits, located in the outer-belt main. It orbits the Sun at a distance of 2.5–3.7 AU once every 5 years and 6 months (2,022 days). Its orbit has an eccentricity of 0.19 and an inclination of 1° with respect to the ecliptic.^[1]

The body's observation arc begins 33 year prior to its official discovery observation, with its first identification as A905 UF at Heidelberg in October 1905.^[10]

Physical characteristics

Rotation period

In October 2016, a rotational lightcurve of Heinemann was obtained from photometric observations by French astronomer Matthieu Conjat. Lightcurve analysis gave a rotation period of 22.96 hours with a brightness variation of 0.36 magnitude (U=2+).^[8]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Heinemann measures between 22.435 and 25.52 kilometers in diameter and its surface has an albedo between 0.058 and 0.0944.^[4][5][6][7]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0653 and a diameter of 21.68 kilometers based on an absolute magnitude of 11.9.^[3]

Naming

This minor planet was named after Karl Heinemann (1898–1970), German astronomer and long-time staff member at the Astronomisches Rechen-Institut. His activities included spherical astronomy and the editing of the "Astronomischer Jahresbericht" during 1934–1958.^[2]

The official naming citation was published by the Minor Planet Center on 15 October 1977 (M.P.C. 4238).^[11]