+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   209 Dido (A879 UC) Classification: Main-belt Asteroid          SPK-ID: 2000209 [ 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 103 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .05607269150175424 3.8064e-08   a 3.148564467438511 1.3555e-08 au q 2.972015983382447 1.1878e-07 au i 7.168801686101997 4.761e-06 deg node .6536485569324534 3.2734e-05 deg peri 249.5077606446031 5.423e-05 deg M 197.745794381771 4.4769e-05 deg tp 2459920.230891445371 (2022-Dec-06.73089145) 0.00025581 TDB period 2040.644306622118 5.59 1.3178e-05 3.608e-08 d yr n .1764148699661964 1.1392e-09 deg/d Q 3.325112951494576 1.4315e-08 au   Orbit Determination Parameters    # obs. used (total)      2982      data-arc span      51515 days (141.04 yr)      first obs. used      1879-10-26      last obs. used      2020-11-10      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .43177      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 01:51:50   Additional Information  Earth MOID = 1.96857 au   Jupiter MOID = 1.71736 au   T_jup = 3.194  [ 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 8.2   n/a MPO502154 IRAS observations used: 20 diameter diameter 179.008 km 1.060 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   rotation period rot_per 5.7366 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Behrend, R. (2001) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2002) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2004) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2005) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Warner, B.D. (2005) Minor Planet Bull. 32, 90-92.] [Behrend, R. (2010) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Collaborative Asteroid Lightcurve Link (CALL) (2011) http://www.minorplanetobserver.com/DATA/submissions_results.htm] geometric albedo albedo 0.028   0.004 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   B-V BV 0.691   0.019 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=5; phase (min.=2.98, mean=7.14, max.=12.26) deg. U-B UB 0.294   0.034 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=5; phase (min.=2.98, mean=7.14, max.=12.26) deg. Tholen spectral type spec_T C   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo SMASSII spectral type spec_B Xc   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) 209 Dido (A879 UC)          Discovered 1879-Oct-22 by Peters, C. H. F. at Clinton Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  A879 UC = A909 AB = A909 GB = A912 RB  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-26 19:57 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin