_Roberts.png) Shape model of Roberts from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | Indiana University (Indiana Asteroid Program) |
| Discovery site | Goethe Link Obs. |
| Discovery date | 1 May 1952 |
| Designations | |
| (3428) Roberts | |
Named after | Walter Orr Roberts[1] (American astronomer) |
| 1952 JH · 1952 KB 1972 YQ1 · 1978 JH2 1980 TD15 · 1982 FR1 | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 65.41yr (23,891 d) |
| Aphelion | 3.1044AU |
| Perihelion | 2.2199 AU |
| 2.6621 AU | |
| Eccentricity | 0.1661 |
| 4.34 yr (1,587 d) | |
| 102.91° | |
| 0° 13m 36.84s / day | |
| Inclination | 8.8754° |
| 230.80° | |
| 303.48° | |
| Physical characteristics | |
| 3.278±0.001 h[8][3] | |
| C/S(assumed)[3] | |
| 12.00[2][3][6][7] | |
3428 Roberts (prov. designation:1952 JH) is abackground asteroid from the central regions of theasteroid belt, approximately 17 kilometers (11 miles) in diameter. It was discovered on 1 May 1952, by Indiana University'sIndiana Asteroid Program at itsGoethe Link Observatory near Brooklyn, Indiana, United States.[1] The asteroid has a shortrotation period of 3.28 hours.[3] It was named in memory of American astronomerWalter Orr Roberts.[1]
Roberts is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[4] It orbits the Sun in thecentral asteroid belt at a distance of 2.2–3.1 AU once every 4 years and 4 months (1,587 days;semi-major axis of 2.66 AU). Its orbit has aneccentricity of 0.17 and aninclination of 9° with respect to theecliptic.[2] The body'sobservation arc begins with its official discovery observation at Goethe Link in May 1952.[1]
Thisminor planet was named in memory of American physicist and astronomerWalter Orr Roberts (1915–1990), founding director of theNational Center for Atmospheric Research, who was one of the first astronomers to use acoronagraph for his solar observations in the 1940s.[1] The official naming citation was published by theMinor Planet Center on 5 September 1990 (M.P.C. 16885).[10]
Robertsspectral type is unknown. TheCollaborative Asteroid Lightcurve Link (CALL) generically assumed it to be either aC-type orS-type asteroid.[3]
In March 2008, a rotationallightcurve of Roberts was obtained fromphotometric observations at theOakley Southern Sky Observatory in Australia. Lightcurve analysis gave a well-definedrotation period of 3.278 hours with a high brightness amplitude of 0.58magnitude (U=3), indicative of an elongated shape.[8] In 2016, a modeled lightcurves using photometric data from various sources, gave a sidereal period of3.27835±0.00005 hours and twospin axes of (63.0°, 49.0°) and (231.0°, 49.0°) inecliptic coordinates (λ, β).[9]
According to the surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer, Roberts measures between 17.16 and 18.47 kilometers in diameter and its surface has analbedo between 0.082 and 0.095.[5][6][7]
CALL assumes an albedo of 0.10 – a compromise value between thestony (0.20) andcarbonaceous (0.057) asteroids of the inner and outer main belt, respectively – and calculates a diameter of 16.73 kilometers based on anabsolute magnitude of 12.0.[3]
