| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 30 September 1921 |
| Designations | |
| (959) Arne | |
Named after | Arne Asplind (son ofBror Asplind)[2] |
| A921 SE · 1927 YD 1952 DD2 · 1960 OF A916 YB · 1921 KF | |
| main-belt[1][3] · (outer) background[4][5] | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 103.03yr (37,630 d) |
| Aphelion | 3.8813AU |
| Perihelion | 2.4752 AU |
| 3.1782 AU | |
| Eccentricity | 0.2212 |
| 5.67 yr (2,070 d) | |
| 86.935° | |
| 0° 10m 26.4s / day | |
| Inclination | 4.4967° |
| 58.521° | |
| 333.57° | |
| Physical characteristics | |
| 123.7±0.1 h[9][10] | |
| X(SDSS-MOC)[11] | |
| 10.8[1][3] | |
959 Arne (prov. designation:A921 SEor1921 KF) is abackground asteroid andslow rotator, approximately 52 kilometers (32 miles) in diameter, located in the outer region of theasteroid belt. It was discovered by German astronomerKarl Reinmuth at theHeidelberg-Königstuhl State Observatory on 30 September 1921.[1] TheX-type asteroid has an exceptionally longrotation period of 123.7 hours. It was named after Arne Asplind, son of Swedish astronomerBror Asplind (1890–1954).[2]
Arne is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[4][5] It orbits the Sun in theouter asteroid belt at a distance of 2.5–3.9 AU once every 5 years and 8 months (2,070 days;semi-major axis of 3.18 AU). Its orbit has aneccentricity of 0.22 and aninclination of 4° with respect to theecliptic.[3] The body'sobservation arc begins with its first observation asA916 YB (1916 YB) atHeidelberg Observatory on 27 December 1916, almost 5 years prior to its official discovery observation on 30 September 1921.[1]
Thisminor planet was named after Arne Asplind, son of Swedish astronomerBror Ansgar Asplind (1890–1954). Asteroids958 Asplinda,960 Birgit and961 Gunnie are named after him and his two daughters, respectively. Thenaming was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 92).[2]
In theSDSS-based taxonomy,Arne anX-type asteroid.[5][11]
In November 2007, a rotationallightcurve ofArne was obtained fromphotometric observations byRobert Stephens at GMARS (G79) and Santana observatories (646) in California. Analysis gave a bimodal lightcurve with an exceptionally longrotation period of123.7±0.1 hours and a brightness amplitude of0.24±0.05magnitude (U=3−).[9][10] The results supersede an incorrect period of 8.60 hours from a noisy lightcurve taken by Larry E. Robinson at Sunflower Observatory (739) in Kansas in November 2001 (U=1).[12]
According to the surveys carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE), the JapaneseAkari satellite, and the Infrared Astronomical SatelliteIRAS,Arne measures45.176±0.350,53.09±0.75 and57.42±1.5 kilometers in diameter, and its surface has analbedo of0.0446±0.002,0.054±0.002 and0.067±0.004, respectively.[6][7][8]
Other published measurements by the WISE team also includes mean-diameters of46.687±0.665 km51.539±0.547 km,52.57±13.47 km and61.45±20.10 km with corresponding albedos of0.067±0.004,0.0553±0.0301,0.03±0.05 and0.03±0.02.[5][9] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0258 and a diameter of 57.20 km based on anabsolute magnitude of 10.8.[9] Anasteroid occultation on 3 February 2015, gave a best-fit ellipse dimension of 53.0 × 53.0 kilometers.[5] These timed observations are taken when the asteroid passes in front of a distant star. However the quality of the measurements are poorly rated.[5]
