+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1491 Balduinus (1938 EJ) Classification: Outer Main-belt Asteroid          SPK-ID: 2001491 [ 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 30 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1347457048584179 3.1166e-08   a 3.24117161793593 1.3881e-08 au q 2.804437663710055 9.6664e-08 au i 3.673693538173701 3.8044e-06 deg node 313.3990034391586 6.5309e-05 deg peri 156.2464856007785 6.7493e-05 deg M 150.6782704972011 1.7181e-05 deg tp 2458108.428645929952 (2017-Dec-20.92864593) 0.00010036 TDB period 2131.33377762776 5.84 1.3691e-05 3.748e-08 d yr n .1689083163692414 1.085e-09 deg/d Q 3.677905572161806 1.5751e-08 au   Orbit Determination Parameters    # obs. used (total)      2621      data-arc span      32858 days (89.96 yr)      first obs. used      1930-10-16      last obs. used      2020-10-01      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .43309      source      ORB      producer      Otto Matic      solution date      2020-Nov-13 04:18:27   Additional Information  Earth MOID = 1.82163 au   Jupiter MOID = 1.4391 au   T_jup = 3.166  [ 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 11.4   n/a MPO347528   diameter diameter 21.941 km 0.213 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 15.315 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Odden, C.E.; Cohen, A.J.; Davis, S.; Eldracher, E.A.; et al. (2018) Minor Planet Bull. 45, 278-279.] [Loera-Gonzalez, P.; Olguan, L.; Contreras, M.E.; Saucedo M.; et al. (2019) Minor Planet Bull. 46, 283-285.] geometric albedo albedo 0.048   0.010 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   1491 Balduinus (1938 EJ)          Discovered 1938-Feb-23 by Delporte, E. at Uccle Discovery is clearly Feb. 23. By error the provisional designation 1938 EJ rather than a D designation was assigned. Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1938 EJ = 1930 UR = 1959 XJ = 1975 RP1  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-28 06:36 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin