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65803 Didymos (1996 GT)
Classification: Apollo [NEO, PHA]          SPK-ID: 2065803
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 181 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .383697480609711 2.7422e-09  
a 1.644394196638894 2.9335e-09 au
q 1.013444286259321 5.1199e-09 au
i 3.407705711883407 1.3274e-06 deg
node 73.19943499617158 9.6759e-06 deg
peri 319.3188680163129 1.1002e-05 deg
M 136.6502277847489 3.5113e-06 deg
tp 2459104.141860697233
(2020-Sep-11.64186070)
7.1631e-06 TDB
period 770.2067669787134
2.11
2.061e-06
5.643e-09
d
yr
n .4674069554233733 1.2507e-09 deg/d
Q 2.275344107018468 4.0591e-09 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A2 [EST] -1.885839515169381E-14 7.227E-15
ALN [SET] 1. n/a
NK [SET] 0. n/a
NM [SET] 2. n/a
NN [SET] 0. n/a
R0 [SET] 1. n/a
  Orbit Determination Parameters
   # obs. used (total)      1046  
   # delay obs. used      5  
   # Doppler obs. used      0  
   data-arc span      9066 days (24.82 yr)  
   first obs. used      1996-04-11  
   last obs. used      2021-02-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .37476  
   source      ORB  
   producer      Steve Chesley  
   solution date      2021-Feb-13 14:47:32  

Additional Information
 Earth MOID = .0401437 au 
 Jupiter MOID = 3.1682 au 
 T_jup = 4.201 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 18.07   n/a MPCxxxxx  
diameter diameter 0.78 km 0.08 Richardson et al., 2016, "Dynamical and Physical Properties of 65803 Didymos", LPSC Abstract (submitted) uncertainty is published as "10%"
bulk density density 2.1 g/cm^3 0.6 Richardson et al., 2016, "Dynamical and Physical Properties of 65803 Didymos", LPSC Abstract (submitted) uncertainty is published as "30%"
rotation period rot_per 2.2593 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Pravec, P.; et al. (2003) IAUC 8244. (65803)]
[Kitazato, K.; Abe, M.; Mito, H. (2005) Asia-Oceana Geophys. Soc. abstract 58-PS-A1183.]
[Pravec, P.; et al. (2006) Icarus 181, 63-93.]
SMASSII spectral type spec_B Xk   n/a Binzel et al. (2004) Meteorit. Planet. Sci. 39, 351-366  

65803 Didymos           Discovered 1996 Apr. 11 by Spacewatch at Kitt Peak.
Greek for "twin", this rapid-rotator Amor possesses a satellite with an orbital period of 11.9 hr. Suspicions arose in the Goldstone delay-Doppler echoes, and these were confirmed with the optical light curve analysis, along with Arecibo radar imaging on 2003 Nov. 23. The name was suggested by J. Montani.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20040713/MPCPages.arcLast Updated: 2004-07-14

[ show close-approach data ]
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