1205 Ebella

1205 Ebella (provisional designation 1931 TB₁) is a relatively eccentric asteroid from the central regions of the asteroid belt, approximately 5.5 kilometers in diameter. It was discovered by astronomer Karl Reinmuth at Heidelberg Observatory on 6 October 1931. The asteroid was named after German astronomer Martin Ebell.^[5]

1205 Ebella

Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	6 October 1931
Designations
MPC designation	(1205) Ebella
Named after	Martin Ebell (German astronomer)[2]
Alternative designations	1931 TB1 · 1970 JT
Minor planet category	main-belt · (middle)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	85.48 yr (31,221 days)
Aphelion	3.2287 AU
Perihelion	1.8411 AU
Semi-major axis	2.5349 AU
Eccentricity	0.2737
Orbital period (sidereal)	4.04 yr (1,474 days)
Mean anomaly	103.87°
Mean motion	0° 14m 39.12s / day
Inclination	8.8616°
Longitude of ascending node	23.083°
Argument of perihelion	349.24°
Physical characteristics
Dimensions	5.474±0.283 km[3] 6.0 km (est. at 0.20)[4]
Geometric albedo	0.214±0.026[3]
Absolute magnitude (H)	13.5[1]

Orbit and classification

Ebella orbits the Sun in the central main-belt at a distance of 1.8–3.2 AU once every 4.04 years (1,474 days). Its orbit has an eccentricity of 0.27 and an inclination of 9° with respect to the ecliptic.^[1] As no precoveries were taken and no prior identifications were made, the asteroid's observation arc begins at Heidelberg with its official discovery observation.^[5]

Physical characteristics

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ebella measures 5.474 kilometers in diameter and its surface has an albedo of 0.214, which is typical for stony S-type asteroids.^[3]

Based on a generic magnitude-to-diameter conversion, it measures 6.0 kilometers in diameter using an absolute magnitude of 13.50 with an assumed albedo of 0.20.^[4]

Lightcurve

As of 2017, no rotational lightcurve of Ebella has been obtained from photometric observations. The asteroid's rotation period, poles and shape still remain unknown.^[1][6]

Naming

This minor planet was named after Carl Wilhelm Ludwig Martin Ebell (1871–1944) an astronomer from Neuruppin, Germany, who was on the editorial team of the renowned astronomical journal Astronomische Nachrichten. The official naming citation was published by Paul Herget in The Names of the Minor Planets in 1955 (H 112).^[2]