+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1555 Dejan (1941 SA) Classification: Main-belt Asteroid          SPK-ID: 2001555 [ 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 36 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2761402773454976 3.236e-08   a 2.691081583639694 7.9265e-09 au q 1.947965568774068 8.8029e-08 au i 6.020622434347088 3.5395e-06 deg node 318.0378456316915 3.3609e-05 deg peri 47.5962152824167 3.4045e-05 deg M 295.620208097121 7.0534e-06 deg tp 2459288.860513959521 (2021-Mar-15.36051396) 3.2355e-05 TDB period 1612.459157712584 4.41 7.1242e-06 1.95e-08 d yr n .2232614688428399 9.8642e-10 deg/d Q 3.434197598505319 1.0115e-08 au   Orbit Determination Parameters    # obs. used (total)      2705      data-arc span      32223 days (88.22 yr)      first obs. used      1932-08-01      last obs. used      2020-10-21      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .41982      source      ORB      producer      Otto Matic      solution date      2020-Nov-13 04:17:50   Additional Information  Earth MOID = .951907 au   Jupiter MOID = 2.06684 au   T_jup = 3.308  [ 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 11.6   n/a MPO435711   diameter diameter 23.199 km 0.314 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   rotation period rot_per 16.960 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Brines, P.; Lozano, J.; Rodrigo, O.; Fornas, A.; et al. (2017) Minor Planet Bull. 44, 145-149.] geometric albedo albedo 0.053   0.006 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   1555 Dejan (1941 SA)          Discovered 1941-Sep-15 by Rigaux, F. at Uccle Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1941 SA = 1932 PC = 1934 CD1 = 1954 NJ  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Nov-28 14:15 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin