+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   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 33 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1505442091012239 4.2088e-08   a 2.784346916873382 1.0764e-08 au q 2.365179612409248 1.1696e-07 au i 8.415794065562105 4.5196e-06 deg node 321.4117743582179 2.3098e-05 deg peri 3.780094920906182 2.6052e-05 deg M 67.40667707404742 1.0869e-05 deg tp 2458682.751241321281 (2019-Jul-18.25124132) 5.1413e-05 TDB period 1697.006262431242 4.65 9.8402e-06 2.694e-08 d yr n .2121382860922626 1.2301e-09 deg/d Q 3.203514221337517 1.2384e-08 au   Orbit Determination Parameters    # obs. used (total)      2209      data-arc span      37654 days (103.09 yr)      first obs. used      1917-09-26      last obs. used      2020-10-29      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .47423      source      ORB      producer      Otto Matic      solution date      2020-Nov-13 04:20:44   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 3.086 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.] [Benishek, V. (2020) Minor Planet Bull. 47, 75-83.] 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.DB Last 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 ] 2021-Jan-28 11:14 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin