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12923 Zephyr (1999 GK4)
Classification: Apollo [NEO, PHA]          SPK-ID: 2012923
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.


Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 355 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .492172654296434 3.2786e-08  
a 1.961659129972277 2.9137e-09 au
q .9961841491489881 6.4854e-08 au
i 5.30536451485022 3.3129e-06 deg
node 168.1878747729737 3.1396e-05 deg
peri 147.0928780202436 3.1655e-05 deg
M 339.9203835465595 5.9645e-06 deg
tp 2459452.474040143317
(2021-Aug-25.97404014)
1.6689e-05 TDB
period 1003.537816487608
2.75
2.2359e-06
6.122e-09
d
yr
n .3587308759923005 7.9926e-10 deg/d
Q 2.927134110795566 4.3478e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2129  
   data-arc span      24247 days (66.38 yr)  
   first obs. used      1955-04-21  
   last obs. used      2021-09-08  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .44098  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Sep-09 05:55:26  

Additional Information
 Earth MOID = .0208539 au 
 Jupiter MOID = 2.41011 au 
 T_jup = 3.717 
[ hide covariance matrix ]
Orbital Elements at Epoch 2457458.5 (2016-Mar-11.0) TDB
Reference: JPL 355 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .49203504667091 3.2778e-08  
q .9965525537924572 6.4857e-08 au
tp 2457445.242224881731
(2016-Feb-26.74222488)
1.4842e-05 TDB
node 168.2131645310619 3.1401e-05 deg
peri 147.0875803409446 3.166e-05 deg
i 5.304381335412888 3.3126e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      2129  
   data-arc span      24247 days (66.38 yr)  
   first obs. used      1955-04-21  
   last obs. used      2021-09-08  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .44098  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Sep-09 05:55:26  

Additional Information
 Jupiter MOID = 2.41011 au 
 T_jup = 3.717 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.074385771369401E-15 -2.125368322690026E-15 -2.289429881198548E-13 4.553594381366424E-15 1.452966760436049E-14 -1.168877050396014E-14
q -2.125368322690026E-15 4.206398599862221E-15 4.553277739663971E-13 -7.497214637606744E-15 -2.945044969396097E-14 2.35045814436695E-14
tp -2.289429881198548E-13 4.553277739663971E-13 2.202847214907615E-10 -1.71667032899005E-12 5.48551370389726E-11 1.123029162876765E-11
node 4.553594381366424E-15 -7.497214637606744E-15 -1.71667032899005E-12 9.860382304042066E-10 -9.81778259050335E-10 2.689186947939706E-11
peri 1.452966760436049E-14 -2.945044969396097E-14 5.48551370389726E-11 -9.81778259050335E-10 1.002349292819277E-9 -2.438456143142875E-11
i -1.168877050396014E-14 2.35045814436695E-14 1.123029162876765E-11 2.689186947939706E-11 -2.438456143142875E-11 1.097361375368569E-11

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 15.71   n/a MPO636261  
diameter diameter 2.060 km 0.013 urn:nasa:pds:neowise_diameters_albedos::2.0[neos] (http://adsabs.harvard.edu/abs/2011ApJ...743..156M)  
rotation period rot_per 3.891 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Pravec, P.; Wolf, M.; Sarounova, L. (1999) http://www.asu.cas.cz/~ppravec/neo.htm]
geometric albedo albedo 0.199   0.034 urn:nasa:pds:neowise_diameters_albedos::2.0[neos] (http://adsabs.harvard.edu/abs/2011ApJ...743..156M)  
SMASSII spectral type spec_B S:   n/a Binzel et al. (2004) Icarus 170, 259-294 SMASSIR data only, classification consistent with specified type, but uncertain

12923 Zephyr           Discovered 1999 Apr. 11 by the Lowell Observatory Near-Earth Object Search at the Anderson Mesa Station.
The word zephyr derives from the name of the ancient Greek god of the west wind, Zephyros. The name was suggested by M. Smitherman.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20040928/MPCPages.arcLast Updated: 2004-09-28

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