+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   385 Ilmatar (A894 EA) Classification: Main-belt Asteroid          SPK-ID: 2000385 [ 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 100 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1225886915637363 4.0536e-08   a 2.852932181775635 7.2865e-09 au q 2.503194958491684 1.1338e-07 au i 13.55069999910927 3.7357e-06 deg node 344.9424114052404 1.4818e-05 deg peri 188.6975906631774 2.111e-05 deg M 92.5581235698414 1.5667e-05 deg tp 2458547.969724835556 (2019-Mar-05.46972484) 7.6552e-05 TDB period 1760.092931619043 4.82 6.7431e-06 1.846e-08 d yr n .2045346546951073 7.8359e-10 deg/d Q 3.202669405059586 8.1798e-09 au   Orbit Determination Parameters    # obs. used (total)      2348      data-arc span      46277 days (126.70 yr)      first obs. used      1894-03-05      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .49219      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 01:53:12   Additional Information  Earth MOID = 1.50978 au   Jupiter MOID = 1.77848 au   T_jup = 3.253  [ 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 7.6   n/a MPO473766 IRAS observations used: 24 diameter diameter 85.837 km 0.576 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 62.35 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Zeigler, K.W.; Florence, W.B.; Blanco, E.J.; McGaughey, J. (1986) Minor Planet Bull. 13, 25-26.] geometric albedo albedo 0.242   0.042 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   B-V BV 0.847   0.073 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=5.60, mean=15.13, max.=22.96) deg. U-B UB 0.370   0.026 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=3; phase (min.=5.60, mean=14.98, max.=22.96) deg. Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices 385 Ilmatar (A894 EA)          Discovered 1894-Mar-01 by Wolf, M. at Heidelberg Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  A894 EA = 1942 FQ = 1953 TQ = 1987 QG3 = A918 CC  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-26 15:42 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin