| Discovery[1] | |
|---|---|
| Discovered by | E. F. Helin |
| Discovery site | Palomar Obs. |
| Discovery date | 13 September 1985 |
| Designations | |
| (5391) Emmons | |
Named after | Richard Emmons[1] (American astronomer) |
| 1985 RE2 · 1934 RH 1951 RF1 · 1975 VE3 | |
| main-belt[1][2] · (inner) background[3] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 67.86yr (24,787 d) |
| Aphelion | 2.8087AU |
| Perihelion | 1.7108 AU |
| 2.2598 AU | |
| Eccentricity | 0.2429 |
| 3.40 yr (1,241 d) | |
| 220.53° | |
| 0° 17m 24.36s / day | |
| Inclination | 2.5123° |
| 336.40° | |
| 344.75° | |
| Physical characteristics | |
| 5.578±0.083 km[4][5] 5.93 km(calculated)[6] | |
| 3.028±0.004 h[7] | |
| 0.20(assumed)[6] 0.298±0.035[4][5] | |
| C(assumed)[6] S(SDSS-MOC) S(Pan-STARRS)[8] | |
| 13.2[5] 13.4[2] 13.5[6] 13.57±0.29[8] | |
5391 Emmons, provisional designation1985 RE2, is a backgroundasteroid from the inner regions of theasteroid belt, approximately 6 kilometers (4 miles) in diameter. It was discovered on 13 September 1985, by American astronomerEleanor Helin at thePalomar Observatory.[1] The likelyS-type asteroid has arotation period of 3.0 hours.[6] It was named for American astronomerRichard Emmons.[1]
Emmons is a non-family asteroid from the main belt'sbackground population.[3] It orbits the Sun in theinner main-belt at a distance of 1.7–2.8 AU once every 3 years and 5 months (1,241 days;semi-major axis of 2.26 AU). Its orbit has aneccentricity of 0.24 and aninclination of 3° with respect to theecliptic.[2]
The asteroid was first observed as1934 RH at theUnion Observatory in September 1934. The body'sobservation arc begins 35 years prior to its official discovery observation with aprecovery at Palomar in April 1950.[1]
Emmons has been characterized as a common, stonyS-type asteroid by thePan-STARRS' survey and by theSDSS-based taxonomic system (latter poorly secured; LSQ). The asteroid is also a generically assumedC-type.[6][8][9]
In September 2002, a rotationallightcurve ofEmmons was obtained fromphotometric observations by astronomers at theGoodsell Observatory (741). Lightcurve analysis gave arotation period of 3.028 hours with a brightness amplitude of 0.16magnitude (U=2).[7]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Emmons measures 5.578 kilometers in diameter and its surface has analbedo of 0.298,[4][5] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo for a stony asteroid of 0.20, and calculates a diameter of 5.93 kilometers based on anabsolute magnitude of 13.5.[6]
Thisminor planet was named after American astronomerRichard H. Emmons (1919–2005), who was a longtime professor of physics and astronomy at Kent State University and known as "Mr. Astronomy" to the thousands of children and residents who looked at the heavens through his homemade telescopes. From the 1950s to 1963, school children, Boy Scouts, church groups and community organizations visited his North Canton garage, known as "The Star Barn," which he had converted into the area's only planetarium. It seated 38. Emmons was also an early observer of artificial satellites.[1]
The official naming citation was published by theMinor Planet Center on 23 May 2000 (M.P.C. 40701).[10]
