| Discovery [1] | |
|---|---|
| Discovered by | D. D. Balam |
| Discovery site | Climenhaga Obs. |
| Discovery date | 20 October 1987 |
| Designations | |
| (4789) Sprattia | |
Named after | Christopher E. Spratt [1] (Canadian astronomer) |
| 1987 UU2 · 1976 HE1 | |
| main-belt [1][2] · (inner)[3] background [4] | |
| Orbital characteristics [2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 41.82yr (15,276 d) |
| Aphelion | 2.5176AU |
| Perihelion | 1.9596 AU |
| 2.2386 AU | |
| Eccentricity | 0.1246 |
| 3.35 yr (1,223 d) | |
| 45.388° | |
| 0° 17m 39.48s / day | |
| Inclination | 1.2760° |
| 209.73° | |
| 152.92° | |
| Physical characteristics | |
| 3.54±0.42 km[5] 4.172±0.232 km[6][7] 4.22 km(calculated)[3] | |
| 3.136±0.0005 h[8] | |
| 0.20(assumed)[3] 0.279±0.070[6][7] 0.44±0.13[5] | |
| S(Pan-STARRS)[3][9] S(SDSS-MOC)[10] | |
| 13.789±0.002(R)[8] 13.80[5] 13.9[2][7] 14.24[3] 14.24±0.22[9] | |
4789 Sprattia, provisional designation1987 UU2, is a stony backgroundasteroid from the inner regions of theasteroid belt, approximately 4 kilometers (2.5 miles) in diameter. It was discovered on 20 October 1987, by Canadian astronomerDavid Balam at the Climenhaga Observatory (657) in Victoria, Canada. TheS-type asteroid has arotation period of 3.1 hours and was named after Canadian amateur astronomerChristopher E. Spratt.[1][3]
Sprattia is a non-family asteroid from the main belt'sbackground population.[4] It orbits the Sun in theinner asteroid belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,223 days;semi-major axis of 2.24 AU). Its orbit has aneccentricity of 0.12 and aninclination of 1° with respect to theecliptic.[2] The body'sobservation arc begins with its first observation as1976 HE1 at theFélix Aguilar Observatory in April 1976, more than 11 years prior to its official discovery observation at Victoria.[1]
Sprattia has been characterized as a common, stonyS-type asteroid byPan-STARRS and theSloan Digital Sky Survey.[3][9][10]
In December 2011, a rotationallightcurve ofSprattia was obtained fromphotometric observations in the R-band by astronomers at thePalomar Transient Factory in California. Lightcurve analysis gave arotation period of 3.136 hours with a brightness amplitude of 0.17magnitude (U=2).[8]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Sprattia measures between 3.54 and 4.172 kilometers in diameter and its surface has analbedo between 0.28 and 0.44.[5][6][7]
TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for a stony asteroid of 0.20, and calculates a diameter of 4.22 kilometers based on anabsolute magnitude of 14.24.[3]
Thisminor planet was named after Canadian amateur astronomerChristopher E. Spratt (born 1942),[11] a long-time member of theRoyal Astronomical Society of Canada, whose interests involvecomets, minor planets,meteors andvariable stars. The official naming citation was published by theMinor Planet Center on 27 June 1991 (M.P.C. 18465).[1][12]
