Discovery[1] | |
---|---|
Discovered by | M. F. Wolf |
Discovery site | Heidelberg Obs. |
Discovery date | 5 October 1931 |
Designations | |
(1203) Nanna | |
Named after | Anna Risi (model of painter) Anselm Feuerbach[2] |
1931 TA · 1926 RH 1978 AD | |
main-belt · (outer)[3] | |
Orbital characteristics[1] | |
Epoch 16 February 2017 (JD 2457800.5) | |
Uncertainty parameter 0 | |
Observation arc | 90.24 yr (32,960 days) |
Aphelion | 3.6055 AU |
Perihelion | 2.1795 AU |
2.8925 AU | |
Eccentricity | 0.2465 |
4.92 yr (1,797 days) | |
137.21° | |
0° 12m 1.44s / day | |
Inclination | 5.9706° |
224.58° | |
176.38° | |
Physical characteristics | |
Dimensions | 31.80±1.22 km[4] 32.59±0.87 km[5] 35.06 km (derived)[3] 35.18±3.9 km (IRAS:2)[6] 35.92±15.13 km[7] 37.91±12.03 km[8] |
15.6±0.1 h (dated)[9] 18.54±0.01 h[10] 25.80±0.05 h[11] | |
0.028±0.017[7] 0.03±0.01[8] 0.03 (derived)[3] 0.04±0.00[4] 0.0473±0.012 (IRAS:2)[6] 0.056±0.004[5] | |
C[3] | |
11.20[5][6] · 11.60[8] · 11.63±0.24[12] · 11.7[1][3] · 11.71[4][7] | |
1203 Nanna (provisional designation 1931 TA) is a carbonaceous asteroid from the outer region of the asteroid belt, about 35 kilometers in diameter. It was discovered on 5 October 1931, by German astronomer Max Wolf at Heidelberg Observatory in southwest Germany,[13] and named after Anna Risi, a model and mistress of painter Anselm Feuerbach.[2]
Nanna is a dark C-type asteroid. It orbits the Sun at a distance of 2.2–3.6 AU once every 4 years and 11 months (1,797 days). Its orbit has an eccentricity of 0.25 and an inclination of 6° with respect to the ecliptic.[1] In 1926, it was first identified as 1926 RH, extending the body's observation arc by 5 years prior to its official discovery observation.[13]
In September 2009, two rotational lightcurves of Nanna were obtained by American astronomer Brian Warner from photometric observations at his Palmer Divided Observatory in Colorado. The first lightcurve analysis gave a rotation period of 18.54 hours with a brightness variation of 0.12 magnitude (U=2), while the second lightcurve was ambiguous giving a period of 25.80 and 12.90 hours, respectively, and an amplitude of 0.15 (U=2).[10] These results supersede a fragmentary lightcurve taken by French amateur astronomers Federico Manzini, Laurent Bernasconi and René Roy from August 2004, which gave a period of 15.6 hours (U=1).[9]
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Nanna measures between 31.80 and 37.91 kilometers in diameter and its surface has an albedo of 0.028 and 0.056.[4][5][6][7][8] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.03 and a diameter of 35.06 kilometers with an absolute magnitude of 11.7.[3]
This minor planet was named after Anna Risi, a model in several paintings by German classicist painter Anselm Feuerbach.[2] The official naming citation was published by Paul Herget in The Names of the Minor Planets in 1955 (H 112).[2]