1818 Brahms

1818 Brahms, provisional designation 1939 PE, is an asteroid from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 15 August 1939, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.^[4] The asteroid was named after composer Johannes Brahms.^[2]

1818 Brahms

Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	15 August 1939
Designations
MPC designation	(1818) Brahms
Named after	Johannes Brahms (German composer)[2]
Alternative designations	1939 PE · 1936 TF 1955 SU · 1955 TN 1955 UC · A904 RE
Minor planet category	main-belt · (inner)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	112.50 yr (41,092 days)
Aphelion	2.5504 AU
Perihelion	1.7770 AU
Semi-major axis	2.1637 AU
Eccentricity	0.1787
Orbital period (sidereal)	3.18 yr (1,163 days)
Mean anomaly	194.32°
Mean motion	0° 18m 34.92s / day
Inclination	2.9782°
Longitude of ascending node	249.48°
Argument of perihelion	74.560°
Physical characteristics
Dimensions	8±3 km (generic)[3]
Absolute magnitude (H)	13.8[1]

Orbit and classification

Brahms orbits the Sun in the inner main-belt at a distance of 1.8–2.6 AU once every 3 years and 2 months (1,163 days). Its orbit has an eccentricity of 0.18 and an inclination of 3° with respect to the ecliptic.^[1] Brahms was first identified as A904 RE at the discovering observatory in 1904, extending the body's observation arc by 35 years prior to its official discovery observation.^[4]

Physical characteristics

As of 2017, Brahms effective size, albedo and spectral type, as well as its rotation period and shape remain unknown. Based on a magnitude-to-diameter conversion, its generic diameter is between 5 and 11 kilometer for an absolute magnitude of 13.8, and an assumed albedo in the range of 0.05 to 0.25.^[3] Since asteroids in the inner main-belt are typically of stony rather than carbonaceous composition, with albedos of 0.20 or higher, Brahms's diameter can be estimate to measure around 6 kilometers, as the higher its albedo (reflectivity), the lower the body's diameter at a constant absolute magnitude (brightness).^[3]

Naming

This minor planet is named for the German composer Johannes Brahms (1833–1897).^[2] The official naming citation was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3935).^[5]