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JPL Small-Body Database Browser
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1272 Gefion (1931 TZ1)
Classification: Main-belt Asteroid          SPK-ID: 2001272
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 30 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1505442075530882 4.2622e-08  
a 2.78434691720839 1.0838e-08 au
q 2.365179617004369 1.1862e-07 au
i 8.41579409398196 4.6049e-06 deg
node 321.4117743576559 2.3175e-05 deg
peri 3.780094592327222 2.6187e-05 deg
M 67.40667723933406 1.0942e-05 deg
tp 2458682.751240484789
(2019-Jul-18.25124048)		 5.178e-05 TDB
period 1697.006262737513
4.65		 9.9083e-06
2.713e-08		 d
yr
n .2121382860539764 1.2386e-09 deg/d
Q 3.203514217412412 1.247e-08 au
   Orbit Determination Parameters
   # obs. used (total)      2085  
   data-arc span      37384 days (102.35 yr)  
   first obs. used      1917-09-26  
   last obs. used      2020-02-02  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .48327  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-22 15:50:15  

Additional Information
 Earth MOID = 1.35323 au 
 Jupiter MOID = 2.1261 au 
 T_jup = 3.300 
[ 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 12.9   n/a MPO435707  
diameter diameter 6.965 km 0.169 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
rotation period rot_per 3.087 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so.
Published Reference List:
[Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.]
geometric albedo albedo 0.252   0.041 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
SMASSII spectral type spec_B Sl   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)

1272 Gefion (1931 TZ1)          Discovered 1931-Oct-10 by Reinmuth, K. at Heidelberg
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 1931 TZ1 = A917 SF 
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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