+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   2113 Ehrdni (1972 RJ2) Classification: Main-belt Asteroid          SPK-ID: 2002113 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 30 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .09661469747524538 2.4302e-08   a 2.473623949802354 7.8434e-09 au q 2.234635520224678 5.8008e-08 au i 6.431027130277653 5.518e-07 deg node 23.34563519105445 7.5896e-06 deg peri 348.7215360312526 1.3995e-05 deg M 141.5375303470677 9.8487e-06 deg tp 2458641.813656992756 (2019-Jun-07.31365699) 3.8478e-05 TDB period 1421.015917046307 3.89 6.7586e-06 1.85e-08 d yr n .2533398786610978 1.2049e-09 deg/d Q 2.712612379380031 8.6012e-09 au   Orbit Determination Parameters    # obs. used (total)      2744      data-arc span      23083 days (63.20 yr)      first obs. used      1958-01-11      last obs. used      2021-03-24      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .4175      source      ORB      producer      Otto Matic      solution date      2021-May-03 19:59:41   Additional Information  Earth MOID = 1.23386 au   Jupiter MOID = 2.71897 au   T_jup = 3.467  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 12.78   n/a E2021B10   diameter diameter 7.043 km 2.082 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)   rotation period rot_per 13.2 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on fragmentary lightcurve(s), may be completely wrong. Published Reference List: [Binzel, R.P. (1987) Icarus 72, 135-208.] geometric albedo albedo 0.238   0.157 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)   B-V BV 0.840   0.030 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=3.29 deg. 2113 Ehrdni           Discovered 1972 Sept. 11 by N. S. Chernykh at the Crimean Astrophysical Observatory. Named in memory of Ehrdni Tel'dzhievich Delikov (1922-1942), a hero from the Kalmyk S.S.R. who was killed in the Great Patriotic War (1941-1945). NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: MPC 5283 Last Updated: 2007-10-23 Alternate Designations  1972 RJ2 = 1958 AA = 1976 UQ2  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-May-14 02:13 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin