Astronomy:9084 Achristou

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9084 Achristou
Discovery [1]
Discovered byD. J. Asher
Discovery siteSiding Spring Obs.
Discovery date3 February 1995
Designations
(9084) Achristou
Named afterApostolos Christou
(British astronomer)[2]
1995 CS1 · 1980 GV1
Minor planet categorymain-belt · Hungaria [3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc36.64 yr (13,381 days)
|{{{apsis}}}|helion}}2.0048 AU
|{{{apsis}}}|helion}}1.7145 AU
1.8597 AU
Eccentricity0.0780
Orbital period2.54 yr (926 days)
Mean anomaly206.11°
Mean motion0° 23m 18.96s / day
Inclination23.098°
Longitude of ascending node197.54°
72.116°
Earth MOID0.7794 AU
Physical characteristics
Dimensions1.76 km (calculated)[3]
1.916±0.367 km[4][5]
Rotation period8.84±0.02 h[6][lower-alpha 1]
Geometric albedo0.30 (assumed)[3]
0.333±0.078[4][5]
E[3]
Absolute magnitude (H)15.7[1][3] · 15.4[4] · 16.08±0.28[7]


9084 Achristou, provisional designation 1995 CS1, is a stony Hungaria asteroid from the innermost regions of the asteroid belt, about 1.9 kilometers in diameter. It was discovered by British astronomer David J. Asher at Siding Spring Observatory in New South Wales, Australia, on 3 February 1995.[8] The asteroid was named after British planetary astronomer Apostolos Christou.[2]

Orbit and classification

Achristou is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.7–2.0 AU once every 2 years and 6 months (926 days). Its orbit has an eccentricity of 0.08 and an inclination of 23° with respect to the ecliptic.[1] In April 1980, it was first identified as 1980 GV1 at Palomar Observatory, extending the body's observation arc by 15 years prior to its official discovery observation at Siding Spring.[8]

Physical characteristics

Achristou has been characterized as a bright E-type asteroid.[3]

Rotation period

In May 2013, a rotational lightcurve of Achristou was obtained from photometric observations by American astronomer Robert Stephens at the Center for Solar System Studies (U81) in California. Lightcurve analysis gave a rotation period of 8.84 hours with a low brightness variation of 0.09 magnitude ({{{1}}}).[6][lower-alpha 1]

Diameter and albedo

Based on the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Achristou measures 1.9 kilometers in diameter and its surface has an albedo of 0.33,[4][5] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 and calculates a diameter of 1.8 kilometers with an absolute magnitude of 15.7.[3]

Naming

This minor planet was named after Apostolos Christou (born 1968), planetary astronomer and programmer at the North Irish Armagh Observatory, after which the minor planet 10502 Armaghobs was named. His field or research include minor planets in co-orbit with Venus, designing near-Earth asteroids missions, the dwarf planet 1 Ceres, meteor impacts on Venus, as well as the irregular satellite families of the outer planets.[2] The official naming citation was published by the Minor Planet Center on 23 May 2005 (M.P.C. 54173).[9]

Notes

  1. 1.0 1.1 Stephens (2013): lightcurve plot of (9084) Achristou with a rotation period 8.84±0.02 hours with a brightness amplitude of 0.09 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL)

References

  1. 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 9084 Achristou (1995 CS1)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009084. 
  2. 2.0 2.1 2.2 Schmadel, Lutz D. (2006). "(9084) Achristou [1.86, 0.08, 23.1]". Dictionary of Minor Planet Names – (9084) Achristou, Addendum to Fifth Edition: 2003–2005. Springer Berlin Heidelberg. p. 42. doi:10.1007/978-3-540-34361-5_303. ISBN 978-3-540-34360-8. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 "LCDB Data for (9084) Achristou". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9084%7CAchristou. 
  4. 4.0 4.1 4.2 4.3 Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D. et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal 741 (2): 25. doi:10.1088/0004-637X/741/2/90. Bibcode2011ApJ...741...90M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...90M. Retrieved 28 April 2016. 
  5. 5.0 5.1 5.2 Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J. et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal 741 (2): 20. doi:10.1088/0004-637X/741/2/68. Bibcode2011ApJ...741...68M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M. Retrieved 4 December 2016. 
  6. 6.0 6.1 Stephens, Robert D.; Coley, Daniel; Warner, Brian D. (January 2014). "Collaborative Asteroid Lightcurve Analysis at the Center for Solar System Studies: 2013 April-June". The Minor Planet Bulletin 41 (1): 8–13. ISSN 1052-8091. Bibcode2014MPBu...41....8S. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014MPBu...41....8S. Retrieved 28 April 2016. 
  7. Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus 261: 34–47. doi:10.1016/j.icarus.2015.08.007. Bibcode2015Icar..261...34V. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V. Retrieved 28 April 2016. 
  8. 8.0 8.1 "9084 Achristou (1995 CS1)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=9084. 
  9. "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html. 

External links