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4587 Rees, provisional designation 3239 T-2, is a Mars-crosser and former near-Earth object on an eccentric orbit from the asteroid belt, approximately 2 kilometers (1.2 miles) in diameter. It was discovered during the second Palomar–Leiden Trojan survey on 30 September 1973, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, and Tom Gehrels at the Palomar Observatory in California. The assumed S-type asteroid has a rotation period of 7.9 hours and is likely elongated in shape. It was named after British astrophysicist Martin Rees.

Orbit and classification

Rees is a Mars-crossing asteroid, a dynamically unstable group between the main belt and the near-Earth populations, crossing the orbit of Mars at 1.66 AU. 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 high eccentricity of 0.51 and an inclination of 25° with respect to the ecliptic. The body's observation arc begins with its first observation as 6378 P-L at Palomar in September 1960, or 13 years prior to its official discovery observation.

Former near-Earth object

Before 2014, Rees has been a near-Earth object of the Amor group, as its perihelion was slightly less than 1.3 AU due to the body's osculating orbit.

Close approaches

In July 2072, Rees will pass 20,686,000 km (0.13828 AU) from Mars, 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.

Palomar–Leiden Trojan survey

The survey designation "T-2" stands for the second Palomar–Leiden Trojan survey, named after the fruitful collaboration of the Palomar and Leiden Observatory in the 1960s and 1970s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of several thousand asteroid discoveries.

Naming

This minor planet was named after Martin Rees (born 1942), a much awarded English cosmologist and astrophysicist who has studied the galactic evolution. Rees became Astronomer Royal and President of the Royal Society in 1995 and 2005, respectively. He is also the director of the Institute of Astronomy and a professor of astronomy at the University of Cambridge. The asteroid's name was proposed by Jan Oort, and the official citation was published by the Minor Planet Center on 28 April 1991 (M.P.C. 18143).

In fiction

Asteroid 4587 is mentioned in Arthur C. Clarke's 1975 (so not then yet named Rees) novel Imperial Earth as the site of a black hole factory where the singularity used in the Asymptotic Drive to power the spaceship Sirius featured in the book is manufactured.

Physical characteristics

Rees is an assumed, stony S-type asteroid. Other sources published by EARN assume an Sr-subtype that transitions from the S-type to the rare R-type asteroids.

Rotation period

In May 2016, a rotational lightcurve of Rees was obtained from photometric observations by Robert Stephens at the Center for Solar System Studies in California. Lightcurve analysis gave a well-defined rotation period of 7.879±0.002 hours with a brightness variation of 0.55 magnitude (U=3), indicative of an elongated, non-spheroidal shape. The result confirms previous observations by Czech astronomer Petr Pravec (7.7886 h) and by astronomers at the Palomar Transient Factory (7.790 h) from April 2003 and October 2012, respectively (U=3/2).

Diameter and albedo

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for an S-type asteroid of 0.20 and calculates a diameter of 2.03 kilometers based on an absolute magnitude of 15.87.

Notes

1. ^ Archived JPL-data of 4587 Rees from January 2010 and September 2012
2. ^ Lightcurve plot of (4587) Rees from May 2016 by Robert Stephens at the Center for Solar System Studies (U81). Period of 7.879±0.01 hour with an amplitude of 0.55 magnitude. Quality code is 3 (lightcurve rating at CS3). Summary figures at the LCDB and CS3.
3. Lightcurve observation in April 2003 by Petr Pravec: rotation period 7.7886±0.0027 hours with a brightness amplitude of 0.78 mag. Quality code is 3. Summary figures for (4587) Rees at the LCDB and data sheet from the Ondrejov Asteroid Photometry Project.

References

1. ^ "4587 Rees (3239 T-2)". Minor Planet Center. Retrieved 30 October 2018.
2. ^ "JPL Small-Body Database Browser: 4587 Rees (3239 T-2)" (2017-10-30 last obs.). Jet Propulsion Laboratory. Retrieved 30 October 2018.
3. ^ "LCDB Data for (4587) Rees". Asteroid Lightcurve Database (LCDB). Retrieved 30 October 2018.
4. ^ Stephens, Robert D. (October 2016). "Asteroids Observed from CS3: 2016 April - June". The Minor Planet Bulletin. 43 (4): 336–339. Bibcode:2016MPBu...43..336S. ISSN 1052-8091. PMC 7243975. PMID 32455386.
5. ^ "Physical parameters of NEOs". European Asteroid Research Node. Archived from the original on 2 February 2013. Retrieved 8 December 2007.
6. "NEO Groups". CNEOS – Center for Near-Earth Object Studies. Retrieved 30 October 2018.
7. Horizons output. "Geoentric Osculating Orbital Elements for Asteroid 4587 Rees (3239 T-2)". Retrieved 4 June 2012. (Selected Ephemeris Type: Elements)
8. "JPL Small-Body Database Browser: Close-Approach Data 4587 Rees (3239 T-2)" (2017-10-30 last obs.). Jet Propulsion Laboratory. Retrieved 30 October 2018.
9. "Minor Planet Discoverers (by number)". Minor Planet Center. 26 October 2018. Retrieved 30 October 2018.
10. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 30 October 2018.
11. Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. S2CID 8342929.

External links

• Asteroid 4587 Rees, Small Bodies Data Ferret
• Dictionary of Minor Planet Names, Google books
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 4587 Rees at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 4587 Rees at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Mars-crossing asteroids
• Unusual minor planets
• Discoveries by Cornelis Johannes van Houten
• Discoveries by Ingrid van Houten-Groeneveld
• Discoveries by Tom Gehrels
• Discoveries by the Palomar–Leiden Trojan-2 survey
• Named minor planets
• Palomar–Leiden survey catalog
• Astronomical objects discovered in 1973