| Discovery[1] | |
|---|---|
| Discovered by | C. J. van Houten I. van Houten-G. T. Gehrels |
| Discovery site | Palomar Obs. |
| Discovery date | 30 September 1973 |
| Designations | |
| (4587) Rees | |
Named after | Martin Rees[1] (British cosmologist) |
| 3239 T-2 · 1990 HQ 6378 P-L | |
| Mars-crosser formerlyAmor[a] | |
| Orbital characteristics[2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 57.10yr (20,855 d) |
| Aphelion | 4.0117AU |
| Perihelion | 1.3057 AU |
| 2.6587 AU | |
| Eccentricity | 0.5089 |
| 4.34 yr (1,583 d) | |
| 232.48° | |
| 0° 13m 38.64s / day | |
| Inclination | 24.626° |
| 180.37° | |
| 83.989° | |
| Earth MOID | 0.5364 AU (209LD) |
| TJupiter | 3.0760 |
| Physical characteristics | |
| 2.03 km(calculated)[3] | |
| 7.879±0.002 h[4][b] | |
| 0.20(assumed)[3] | |
| S/Sr(assumed)[3][5] | |
| 15.3[1][2] 15.87[3] | |
4587 Rees, provisional designation3239 T-2, is aMars-crosser and formernear-Earth object on an eccentric orbit from theasteroid belt, approximately 2 kilometers (1.2 miles) in diameter. It was discovered during the secondPalomar–Leiden Trojan survey on 30 September 1973, by Dutch astronomer coupleIngrid andCornelis van Houten at Leiden, andTom Gehrels at thePalomar Observatory in California.[1] The assumedS-type asteroid has arotation period of 7.9 hours and is likely elongated in shape.[3] It was named after British astrophysicistMartin Rees.[1]
Rees is aMars-crossing asteroid, a dynamically unstable group between themain belt and thenear-Earth populations, crossing the orbit ofMars at 1.66 AU.[1] It orbits the Sun at a distance of 1.31–4.01 AU once every 4 years and 4 months (1,583 days;semi-major axis of 2.66 AU). Its orbit has a higheccentricity of 0.51 and aninclination of 25° with respect to theecliptic.[2] The body'sobservation arc begins with its first observation as6378 P-L atPalomar in September 1960, or 13 years prior to its official discovery observation.[1]
Before 2014,Rees has been anear-Earth object of theAmor group,[a] as itsperihelion was slightly less than 1.3 AU due to the body'sosculating orbit.[6][7]
In July 2072,Rees will pass 20,686,000 km (0.13828 AU) fromMars, the closest since it passed 15,810,000 km (0.1057 AU) from the Red Planet on 28 January 1843. The asteroid will also pass 7,110,000 km (0.0475 AU) from the second largest asteroid,4 Vesta, on 30 January 2121.[8]
Thesurvey designation "T-2" stands for the secondPalomar–Leiden Trojan survey, named after the fruitful collaboration of the Palomar andLeiden Observatory in the 1960s and 1970s. Gehrels used Palomar'sSamuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped thephotographic plates to Ingrid and Cornelis van Houten at Leiden Observatory whereastrometry was carried out. The trio are credited with the discovery ofseveral thousand asteroid discoveries.[9]
Thisminor planet was named afterMartin Rees (born 1942), a much awarded Englishcosmologist andastrophysicist who has studied thegalactic evolution. Rees becameAstronomer Royal andPresident of the Royal Society in 1995 and 2005, respectively. He is also the director of theInstitute of Astronomy and a professor of astronomy at theUniversity of Cambridge. The asteroid's name was proposed byJan Oort, and theofficial citation was published by theMinor Planet Center on 28 April 1991 (M.P.C. 18143).[10]
Asteroid 4587 is mentioned inArthur C. Clarke's 1975 (so not then yet named Rees) novelImperial Earth as the site of ablack hole factory where thesingularity used in the Asymptotic Drive to power the spaceshipSirius featured in the book is manufactured.
Rees is an assumed, stonyS-type asteroid.[3] Other sources published byEARN assume an Sr-subtype that transitions from the S-type to the rareR-type asteroids.[5]
In May 2016, a rotationallightcurve ofRees was obtained fromphotometric observations byRobert Stephens at theCenter for Solar System Studies in California. Lightcurve analysis gave a well-definedrotation period of7.879±0.002 hours with a brightness variation of 0.55magnitude (U=3), indicative of an elongated, non-spheroidal shape.[4][b] The result confirms previous observations by Czech astronomerPetr Pravec (7.7886 h) and by astronomers at thePalomar Transient Factory (7.790 h) from April 2003 and October 2012, respectively (U=3/2).[3][11][c]
TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for anS-type asteroid of 0.20 and calculates a diameter of 2.03 kilometers based on anabsolute magnitude of 15.87.[3]
