990 Yerkes is a main belt asteroid discovered by Belgian-American astronomer George Van Biesbroeck in 1922, and named after the Yerkes Observatory.

990 Yerkes
Discovery
Discovered byG. Van Biesbroeck
Discovery siteWilliams Bay
Discovery date23 November 1922
Designations
(990) Yerkes
Pronunciation/ˈjɜːrkz/
1922 MZ
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc102.46 yr (37425 days)
Aphelion3.2477 AU (485.85 Gm)
Perihelion2.0916 AU (312.90 Gm)
2.6696 AU (399.37 Gm)
Eccentricity0.21652
4.36 yr (1593.2 d)
216.84°
0° 13m 33.456s / day
Inclination8.7872°
353.971°
9.4832°
Physical characteristics
9.23±0.6 km
24.56 h (1.023 d)
24.45 ± 0.05[2] h
0.1303±0.018
11.7

Photometric observations of this asteroid collected during 2009 show a rotation period of 24.45 ± 0.05 hours with a brightness variation of 0.35 ± 0.05 magnitude.[2]

References

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  1. ^ "990 Yerkes (1922 MZ)". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 2 May 2016.
  2. ^ a b Ruthroff, John C. (April 2010), "Lightcurve Analysis of Asteroid 990 Yerkes", The Minor Planet Bulletin, 37 (2): 74, Bibcode:2010MPBu...37...74R.
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