9564 Jeffwynn

9564 Jeffwynn
Discovery [1]
Discovered byC. S. Shoemaker
E. M. Shoemaker
Discovery sitePalomar Obs.
Discovery date26 September 1987
(9564) Jeffwynn
Named after
Jeffrey Wynn
(American geophysicist)[2]
1987 SG3 · 1951 NQ
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc65.68 yr (23,988 days)
Aphelion3.0828 AU
Perihelion1.5962 AU
2.3395 AU
3.58 yr (1,307 days)
0° 16m 31.44s / day
Physical characteristics
Dimensions4.71 km (calculated)[3]
3.035±0.001 h[4][a]
0.20 (assumed)[3]
13.00[5] · 14.0[1][3] · 14.52±0.76[6]

9564 Jeffwynn, provisional designation 1987 SG3, is an eccentric asteroid and Mars-crosser from the inner regions of the asteroid belt, approximately 4.7 kilometers in diameter.

The asteroid was discovered on 26 September 1987, by American astronomer couple Carolyn and Eugene Shoemaker at Palomar Observatory in California, United States.[7] It was named for American geophysicist Jeffrey C. Wynn.[2]

Orbit and classification[]

Jeffwynn is a stony asteroid that orbits the Sun at a distance of 1.6–3.1 AU once every 3 years and 7 months (1,307 days). Its orbit has an eccentricity of 0.32 and an inclination of 22° with respect to the ecliptic.[1]

The body's observation arc begins 36 years prior to its official discovery observation, with its precovery identification as 1951 NQ at Palomar in July 1951.[7]

Physical characteristics[]

Jeffwynn has been characterized as a common, stony S-type asteroid by photometry from the Sloan Digital Sky Survey.[3][5]


In September 2012, a rotational lightcurve of Jeffwynn was obtained from photometric observations by American astronomer Brian Warner at his Palmer Divide Observatory (716) in Colorado. Lightcurve analysis gave a well-defined rotation period of 3.035 hours with a brightness variation of 0.16 magnitude (U=3).[4][a]

Diameter and albedo[]

The Collaborative Asteroid Lightcurve Link calculates a diameter of 4.7 kilometers with an absolute magnitude of 14.0 and an assumed albedo for stony asteroids of 0.20.[3]


This minor planet was named in honor of American Jeffrey C. Wynn, research geophysicist with the United States Geological Survey, described as a "humorous, curious, inventive, adventurous geophysicist", who examined the Saudi Arabian Wabar craters on several expions in 1994 and 1995, together with Eugene Shoemaker, after whom the minor planet 2074 Shoemaker is named. Wynn's research included mapping the seafloor, analyzing terrestrial minerals, and studying aquifers and archaeological sites. He also observed with the comet-discovering Shoemaker-Levy team.[2] The official naming citation was published by the Minor Planet Center on 23 November 1999 (M.P.C. 36948).[8]


  1. ^ a b Warner (2012): lightcurve plot of (9564) Jeffwynn with a rotation period 3.0350±0.001 hours and a brightness amplitude of 0.16 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL)


  1. ^ a b c d e "JPL Small-Body Database Browser: 9564 Jeffwynn (1987 SG3)" (2017-03-14 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(9564) Jeffwynn". Dictionary of Minor Planet Names – (9564) Jeffwynn. Springer Berlin Heidelberg. p. 699. doi:10.1007/978-3-540-29925-7_7587. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g "LCDB Data for (9564) Jeffwynn". Asteroid Lightcurve Database (LCDB). Retrieved 29 July 2016.
  4. ^ a b Warner, Brian D. (January 2013). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2012 June - September". The Minor Planet Bulletin. 40 (1): 26–29. Bibcode:2013MPBu...40...26W. ISSN 1052-8091. Retrieved 1 January 2016.
  5. ^ a b c Carry, B.; Solano, E.; Eggl, S.; DeMeo, F. E. (April 2016). "Spectral properties of near-Earth and Mars-crossing asteroids using Sloan photometry". Icarus. 268: 340–354. arXiv:1601.02087. Bibcode:2016Icar..268..340C. doi:10.1016/j.icarus.2015.12.047. Retrieved 29 July 2016.
  6. ^ 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. Retrieved 29 July 2016.
  7. ^ a b "9564 Jeffwynn (1987 SG3)". Minor Planet Center. Retrieved 29 July 2016.
  8. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 29 July 2016.

External links[]