+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   285 Regina (A889 PA) Classification: Main-belt Asteroid          SPK-ID: 2000285 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 48 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2046300276447057 2.4775e-08   a 3.086076317875283 1.1208e-08 au q 2.454572435634792 7.487e-08 au i 17.61641002428757 3.7833e-07 deg node 311.2287407387236 1.2245e-06 deg peri 14.27964063782225 3.9553e-06 deg M 68.56404541259356 3.5064e-06 deg tp 2458823.360211854497 (2019-Dec-05.86021185) 1.7767e-05 TDB period 1980.197097696969 5.42 1.0787e-05 2.953e-08 d yr n .1818000846575784 9.9038e-10 deg/d Q 3.717580200115774 1.3501e-08 au   Orbit Determination Parameters    # obs. used (total)      2876      data-arc span      40000 days (109.51 yr)      first obs. used      1911-09-01      last obs. used      2021-03-07      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .38821      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 10:38:15   Additional Information  Earth MOID = 1.44351 au   Jupiter MOID = 1.63005 au   T_jup = 3.123  [ 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 10.85   n/a E2021B10   diameter diameter 47.156 km 0.310 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 9.542 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Pilcher, F.; Benishek, V. (2010) Minor Planet Bull. 37, 50.] geometric albedo albedo 0.050   0.005 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   285 Regina (A889 PA)          Discovered 1889-Aug-03 by Charlois, A. at Nice Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  A889 PA = 1951 AC1 = A911 QJ  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-19 10:51 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin