| Discovery[1] | |
|---|---|
| Discovered by | E. F. Helin |
| Discovery site | Palomar Obs. |
| Discovery date | 27 February 1990 |
| Designations | |
| (5641) McCleese | |
Named after | Daniel McCleese (JPL scientist)[2] |
| 1990 DJ · 1973 GA | |
| Mars-crosser[1] · Hungaria[3][4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 44.16 yr (16,131 days) |
| Aphelion | 2.0497AU |
| Perihelion | 1.5894 AU |
| 1.8195 AU | |
| Eccentricity | 0.1265 |
| 2.45yr (896 days) | |
| 25.017° | |
| 0° 24m 5.76s / day | |
| Inclination | 22.201° |
| 151.32° | |
| 57.026° | |
| Earth MOID | 0.6553 AU |
| Physical characteristics | |
| Dimensions | 3.67 km(derived)[4] 4.00±0.68 km[5] 5.68±0.5 km(IRAS:2)[6] |
| 7.268±0.001h[7] 28.8±0.6 h[8] 28.8 h[8] 418±10 h[9] | |
| 0.3(assumed)[4] 0.34±0.09[5] 0.4552±0.088(IRAS:2)[6] | |
| SMASS =A[1] · A[4] | |
| 12.70[6] · 14.00[5] · 14.1[1][4][10] | |
5641 McCleese, provisional designation1990 DJ, is a rare-type Hungariaasteroid andslow rotator, classified asMars-crosser from the innermost regions of theasteroid belt, approximately 4 kilometers in diameter.
It was discovered on 27 February 1990, by American astronomerEleanor Helin atPalomar Observatory in California, and later named forJPL-scientist Daniel McCleese.[2][3]
McCleese is classified as a bright and rareA-type asteroid in theSMASS taxonomy.[11] It is a member of theHungaria family, which form the innermost dense concentration of asteroids in the Solar System.[3] With aperihelion of 1.589 AU,McCleese also crosses the orbit of Mars.
The asteroid orbits the Sun in theinnermost main-belt at a distance of 1.6–2.0 AU once every 2 years and 5 months (896 days). Its orbit has aneccentricity of 0.13 and aninclination of 22° with respect to theecliptic.[1] In 1973, it was first identified as1973 GA atLick Observatory, extending the body'sobservation arc by 17 years prior to its official discovery observation at Palomar.[3]
Photometric observations ofMcCleese byBrian Warner andRené Roy in 2005 and 2007, gave three rotationallightcurves that had arotation period between 7.2 and 28.8 hours with a brightness variation of 0.06 to 0.50magnitude (U=2/2/1).[7][8] In June 2010,McCleese was again observed by Brian Warner at his Palmer Divide Observatory in Colorado, United States. By combining his data points with the previously obtained photometric data, he was able to derive a period of418±10 hours with an amplitude of 1.30 magnitude (U=2).[9] With a period of 418 hours, the body is one of theTop 100 slow rotators known to exist.
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,McCleese measures 5.68 and 4.00 kilometers in diameter, and its surface has analbedo of 0.455 and 0.34, respectively.[5][6] In agreement with WISE, theCollaborative Asteroid Lightcurve Link assumes an albedo of 0.3 and derives a diameter of 3.67 kilometers using anabsolute magnitude of 14.1.[4]
Thisminor planet is named after American JPL scientist Daniel J. McCleese, who is a physicist and manager atJPL's Science Division. He also played an important role for theNear-Earth Asteroid Tracking program (NEAT).[2] The approved naming citation was published by theMinor Planet Center on 4 April 1996 (M.P.C. 26930).[12]
