| Discovery[1] | |
|---|---|
| Discovered by | J. Palisa |
| Discovery site | Vienna Obs. |
| Discovery date | 30 July 1911 |
| Designations | |
| (716) Berkeley | |
| Pronunciation | /ˈbɜːrkliː/[2] |
Named after | Berkeley[3] (U.S. City, California) |
| A911 OC · 1947 CH 1952 FA · A906 OB 1911 MD | |
| Orbital characteristics[4] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 113.32yr (41,390 d) |
| Aphelion | 3.0557AU |
| Perihelion | 2.5682 AU |
| 2.8120 AU | |
| Eccentricity | 0.0867 |
| 4.72 yr (1,722 d) | |
| 136.21° | |
| 0° 12m 32.4s / day | |
| Inclination | 8.4872° |
| 145.89° | |
| 56.811° | |
| Physical characteristics | |
| 15.55±0.04 h[12][a] | |
716 Berkeley (prov. designation:A911 OCor1911 MD) is abackground asteroid from the central regions of theasteroid belt. It was discovered by Austrian astronomerJohann Palisa at theVienna Observatory on 30 July 1911.[1] The stonyS-type asteroid has arotation period of 15.6 hours and measures approximately 21 kilometers (13 miles) in diameter. It was named after the city ofBerkeley, California, where the discoverer's colleagueArmin Otto Leuschner (1868–1953) was the director of the local observatory.[3]
Berkeley is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[5][6][7] It orbits the Sun in thecentral asteroid belt at a distance of 2.6–3.1 AU once every 4 years and 9 months (1,722 days;semi-major axis of 2.81 AU). Its orbit has aneccentricity of 0.09 and aninclination of 8° with respect to theecliptic.[4] The body'sobservation arc begins with its first observation atHeidelberg on 16 July 1906, five years prior to its official discovery observation byJohann Palisa atVienna.[1]
According toAlexander Schnell, thisminor planet was named by the discoverer after the U.S. city ofBerkeley in California, where American astronomer and colleagueArmin Otto Leuschner (1868–1953) was a long-time director at theLeuschner Observatory (then called Students' Observatory). Known for his booksCelestial Mechanics andThe Minor Planets of the Hecuba Group, Leuschner worked on the orbit determination of719 Albert, which was originally discovered by Palisa in 1911 but remained alost asteroid until 2000. The naming citation was not mentioned inThe Names of the Minor Planets byPaul Herget in 1955.[3] Palisa also named asteroid718 Erida after Leuschner's daughter. The lunar craterLeuschner and asteroid1361 Leuschneria, discovered byEugène Delporte in 1935, were later named directly after the American astronomer.
In both theTholen andSMASS classification,Berkeley is a common, stonyS-type asteroid.[4] It is also an S-type in theBus–DeMeo classification,[13] while in the Tholen- and SMASS-like taxonomic variants of theSmall Solar System Objects Spectroscopic Survey (S3OS2), this asteroid is aK-type and Sq-subtype which transitions to the uncommonQ-type, respectively.[6][14]
In May 2009, a rotationallightcurve ofBerkeley was obtained fromphotometric observations by American amateur astronomer Joe Garlitz at his Elgin Observatory in Oregon. Lightcurve analysis gave arotation period of15.55±0.04 hours with a brightness variation of0.25±0.03magnitude (U=2+).[a] Lower rated lightcurves obtained byClaes-Ingvar Lagerkvist in 1977, and byDavid Romeuf in 2018, gave a divergent period of larger than17 h and34.3±0.6 h with an amplitude of larger than0.2 and0.25±0.02 magnitude, respectively (U=1/2).[15][16]
According to the surveys carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE), the Infrared Astronomical SatelliteIRAS, and the JapaneseAkari satellite,Berkeley measures (19.768±0.167), (21.28±1.5) and (21.55±0.57) kilometers in diameter and its surface has analbedo of (0.220±0.045), (0.1801±0.028) and (0.182±0.011), respectively.[8][9][10][11]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.2027 and a diameter of 21.38 kilometers based on anabsolute magnitude of 10.7.[12] Alternative mean-diameters published by the WISE team include (21.519±0.054 km) and (21.89±0.78 km) with a corresponding albedo of (0.1808±0.0518) and (0.170±0.017).[6][12]
