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]