1020 Arcadia
Main-belt asteroid
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1020 Arcadia, provisional designation 1924 QV, is a stony Agnia asteroid from the central regions of the asteroid belt, approximately 11 kilometers (7 miles) in diameter. It was discovered on 7 March 1924, by German astronomer Karl Reinmuth at the Heidelberg Observatory in Heidelberg, Germany.[1] The asteroid was named after the Greek region of Arcadia.[3]
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 7 March 1924 |
| Designations | |
| (1020) Arcadia | |
| Pronunciation | /ÉËrËkeɪdiÉ/[2] |
Named after | Arcadia (Greek region)[3] |
| 1924 QV · 1954 UA2 1975 EQ · 1977 QO2 | |
| main-belt[1][4] · (middle) Agnia[5][6] | |
| Orbital characteristics[4] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 93.89 yr (34,293 d) |
| Aphelion | 2.9152 AU |
| Perihelion | 2.6666 AU |
| 2.7909 AU | |
| Eccentricity | 0.0445 |
| 4.66 yr (1,703 d) | |
| 18.189° | |
| 0° 12m 41.04s / day | |
| Inclination | 4.0598° |
| 180.71° | |
| 37.691° | |
| Physical characteristics | |
| 10.067±0.090 km[7] 10.415±0.123 km[8] 13.02±0.49 km[9] 21.16 km (calculated)[10] | |
| 17.02±0.02 h[11] | |
| 0.057 (assumed)[10] 0.150±0.023[9] 0.2364±0.0456[8] | |
| SMASS = S[4] · S[12] S(SDSS-MFB)[10] | |
| 12.0[4] · 12.10[8][9][10] 12.29±0.11[12] | |
Orbit and classification
Arcadia is a member of the Agnia family (514),[5][6] a very large family of stony asteroids with more than 2000 known members.[13] They most likely formed from the breakup of a basalt object, which in turn was spawned from a larger parent body that underwent igneous differentiation.[6] The family's parent body and namesake is the asteroid 847 Agnia.[13]
It orbits the Sun in the central main-belt at a distance of 2.7â2.9 AU once every 4 years and 8 months (1,703 days; semi-major axis of 2.79 AU). Its orbit has an eccentricity of 0.04 and an inclination of 4° with respect to the ecliptic.[4] The body's observation arc begins at Heidelberg in March 1924, six days after its official discovery observation.[1]
Physical characteristics
In the SMASS classification, Arcadia is a common, stony S-type asteroid.[4] It has been characterized as an S-type by Pan-STARRS photometric survey,[12] as well as by SDSS-MFB (Masi Foglia Bus).[10]
Rotation period
In November 2011, a fragmentary rotational lightcurve of Arcadia was obtained from photometric observations by Gordon Gartrelle at the University of North Dakota. Lightcurve analysis gave a rotation period of 17.02 hours with a brightness amplitude of 0.05 magnitude (U=1).[11] As of 2018, no secure period has been obtained.[10]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Arcadia measures between 10.067 and 13.02 kilometers in diameter and its surface has an albedo between 0.150 and 0.2364.[7][8][9] The Collaborative Asteroid Lightcurve Link assumes an albedo 0.057, i.e. an albedo for a carbonaceous rather than for a stony asteroid, and consequently calculates a much larger diameter of 21.16 kilometers based on an absolute magnitude of 12.1.[10] It may be speculated whether this anomaly is a glitch in the data base.
Naming
This minor planet was named after the Greek region of Arcadia in central Peloponnese. It is also a celebrated mythological region, where the shepherd god Pan lived. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 97).[3]
