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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 29 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1505442025970602 4.2814e-08  
a 2.784346918114011 1.0865e-08 au
q 2.365179631572955 1.1922e-07 au
i 8.415794400744028 4.6453e-06 deg
node 321.4117737659141 2.3203e-05 deg
peri 3.780095465852264 2.6213e-05 deg
M 67.40667652281968 1.0958e-05 deg
tp 2458682.751243707347
5.1848e-05 TDB
period 1697.006263565451
n .2121382859504781 1.2417e-09 deg/d
Q 3.203514204655067 1.25e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2057  
   data-arc span      37358 days (102.28 yr)  
   first obs. used      1917-09-26  
   last obs. used      2020-01-07  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .48377  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Jan-28 17:56:59  

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] (  
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] (  
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

[ hide close-approach data ]
Close-Approach Data   ...sorted by Date/Time (TDB)
Date/Time (TDB) Time Uncertainty
Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified
1931-Aug-10 10:57 00:02 Thisb 0.024445930939677 0.0244362557088623 0.024455607327221 2.16269189188669 2.16269176292119 2426563.956552244 2.37140385267171 549.78495807659 34.2374119941635 -28.9106067971426 51865.4473492284 T 29 CATAB v2.0f-lin.ifort 2020-Jan-28 17:57:25 2020-Jan-28 17:57

Alternate Designations
 1931 TZ1 = A917 SF 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
FirstGov 2020-Feb-20 14:49 UT
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