Wikipedia

4789 Sprattia

4789 Sprattia, provisional designation 1987 UU2, is a stony background asteroid from the inner regions of the asteroid belt, approximately 4 kilometers (2.5 miles) in diameter. It was discovered on 20 October 1987, by Canadian astronomer David Balam at the Climenhaga Observatory (657) in Victoria, Canada. The S-type asteroid has a rotation period of 3.1 hours and was named after Canadian amateur astronomer Christopher E. Spratt.[1][3]

4789 Sprattia
Discovery [1]
Discovered byD. D. Balam
Discovery siteClimenhaga Obs.
Discovery date20 October 1987
Designations
(4789) Sprattia
Named after
Christopher E. Spratt [1]
(Canadian astronomer)
1987 UU2 · 1976 HE1
main-belt [1][2] · (inner)[3]
background [4]
Orbital characteristics [2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc41.82 yr (15,276 d)
Aphelion2.5176 AU
Perihelion1.9596 AU
2.2386 AU
Eccentricity0.1246
3.35 yr (1,223 d)
45.388°
0° 17m 39.48s / day
Inclination1.2760°
209.73°
152.92°
Physical characteristics
Mean diameter
3.54±0.42 km[5]
4.172±0.232 km[6][7]
4.22 km (calculated)[3]
3.136±0.0005 h[8]
0.20 (assumed)[3]
0.279±0.070[6][7]
0.44±0.13[5]
S (Pan-STARRS)[3][9]
S (SDSS-MOC)[10]
13.789±0.002 (R)[8]
13.80[5]
13.9[2][7]
14.24[3]
14.24±0.22[9]

Orbit and classification edit

Sprattia is a non-family asteroid from the main belt's background population.[4] It orbits the Sun in the inner asteroid belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,223 days; semi-major axis of 2.24 AU). Its orbit has an eccentricity of 0.12 and an inclination of 1° with respect to the ecliptic.[2] The body's observation arc begins with its first observation as 1976 HE1 at the Félix Aguilar Observatory in April 1976, more than 11 years prior to its official discovery observation at Victoria.[1]

Physical characteristics edit

Sprattia has been characterized as a common, stony S-type asteroid by Pan-STARRS and the Sloan Digital Sky Survey.[3][9][10]

Rotation period edit

In December 2011, a rotational lightcurve of Sprattia was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 3.136 hours with a brightness amplitude of 0.17 magnitude (U=2).[8]

Diameter and albedo edit

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Sprattia measures between 3.54 and 4.172 kilometers in diameter and its surface has an albedo between 0.28 and 0.44.[5][6][7]

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a stony asteroid of 0.20, and calculates a diameter of 4.22 kilometers based on an absolute magnitude of 14.24.[3]

Naming edit

This minor planet was named after Canadian amateur astronomer Christopher E. Spratt (born 1942),[11] a long-time member of the Royal Astronomical Society of Canada, whose interests involve comets, minor planets, meteors and variable stars. The official naming citation was published by the Minor Planet Center on 27 June 1991 (M.P.C. 18465).[1][12]

References edit

  1. ^ a b c d e f "4789 Sprattia (1987 UU2)". Minor Planet Center. Retrieved 3 May 2018.
  2. ^ a b c d "JPL Small-Body Database Browser: 4789 Sprattia (1987 UU2)" (2018-02-25 last obs.). Jet Propulsion Laboratory. Retrieved 3 May 2018.
  3. ^ a b c d e f g h "LCDB Data for (4789) Sprattia". Asteroid Lightcurve Database (LCDB). Retrieved 3 May 2018.
  4. ^ a b "Asteroid 4789 Sprattia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 29 October 2019.
  5. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. S2CID 9341381.
  6. ^ a b c 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. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. S2CID 118745497.
  7. ^ a b c d 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. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. S2CID 35447010. (catalog)
  8. ^ a b c 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.
  9. ^ a b c 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. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID 53493339.
  10. ^ a b Carvano, J. M.; Hasselmann, P. H.; Lazzaro, D.; Mothé-Diniz, T. (February 2010). "SDSS-based taxonomic classification and orbital distribution of main belt asteroids". Astronomy and Astrophysics. 510: 12. Bibcode:2010A&A...510A..43C. doi:10.1051/0004-6361/200913322. Retrieved 30 October 2019. (PDS data set)
  11. ^ "Christopher Spratt". Royal Astronomical Society of Canada. Retrieved 3 May 2018.
  12. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 3 May 2018.

External links edit

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