| Discovery[1] | |
|---|---|
| Discovered by | Perth Obs. |
| Discovery site | Perth Obs. |
| Discovery date | 6 August 1978 |
| Designations | |
| (5542) Moffatt | |
Named after | Ethelwin Moffatt (Australian philanthropist) |
| 1978 PT4 · 1986 LL | |
| main-belt[1][2] · (middle) Maria[3][4] · Eunomia[5] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 39.71yr (14,505 d) |
| Aphelion | 3.0022AU |
| Perihelion | 2.1727 AU |
| 2.5874 AU | |
| Eccentricity | 0.1603 |
| 4.16 yr (1,520 d) | |
| 128.69° | |
| 0° 14m 12.48s / day | |
| Inclination | 15.877° |
| 116.56° | |
| 263.20° | |
| Physical characteristics | |
| 8.597±0.183 km[6][7] 10.06 km(calculated)[5] | |
| 5.187±0.001 h[8] 5.195 h[4] | |
| 0.21(assumed)[5] 0.345±0.055[6][7] | |
| S(assumed)[5] | |
| 12.1[7] 12.3[2][5] 12.67±0.25[9] | |
5542 Moffatt, provisional designation1978 PT4, is a Marianasteroid from the central regions of theasteroid belt, approximately 9 kilometers (6 miles) in diameter. It was discovered on 6 August 1978, by astronomers at thePerth Observatory in Bickley, Australia.[1] The likelyS-type asteroid has arotation period of 5.19 hours.[5] It was named for AustralianEthelwin Moffatt, a benefactor of the discovering observatory.[1]
Moffatt is a core member of theMaria family (506),[3][4] a large intermediate beltfamily ofstony asteroids.[10] Alternatively, it has also been assigned to the stonyEunomia family (502), one of the most prominent families in the intermediate main belt with more than 5,000 members.[5]
It orbits the Sun in thecentral main-belt at a distance of 2.2–3.0 AU once every 4 years and 2 months (1,520 days;semi-major axis of 2.59 AU). Its orbit has aneccentricity of 0.16 and aninclination of 16° with respect to theecliptic.[2] The body'sobservation arc begins with its first observation atPalomar Observatory in July 1978, a month prior to its official discovery observation at Bickley.[1]
Moffatt is an assumed stonyS-type asteroid.[5]
In November 2011, a rotationallightcurve ofMoffatt was obtained fromphotometric observations by Chinese astronomers using the SARA telescopes (G82) of the Southeastern Association for Research in Astronomy atKitt Peak andCTIO. Lightcurve analysis gave arotation period of 5.187 hours and a brightness variation of 0.12magnitude (U=2+).[8] This supersedes a previous result from a fragmentary lightcurve byAlvaro Alvarez-Candal that gave a period of 5.195 hours with an amplitude of 0.27 magnitude (U=1).[4]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Moffatt measures 8.597 kilometers in diameter and its surface has a highalbedo of 0.345.[6][7] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from15 Eunomia, the parent body of the Eunomia family – and calculates a diameter of 10.06 kilometers based on anabsolute magnitude of 12.3.[5]
Thisminor planet was named after AustralianEthelwin Moffatt (née Winzar, born 1926), a benefactor of the discoveringPerth Observatory and a direct descendant ofJohn Flamsteed (1646–1719), the firstAstronomer Royal. The official naming citation was published by theMinor Planet Center on 2 September 2001 (M.P.C. 43380).[11]
