+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1251 Hedera (1933 BE) Classification: Main-belt Asteroid          SPK-ID: 2001251 [ 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 40 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1576141721469449 3.3545e-08   a 2.71738726043168 9.0588e-09 au q 2.289088516976086 9.434e-08 au i 6.049926328660582 3.4972e-06 deg node 140.6285657528618 3.3603e-05 deg peri 217.1328408137612 3.5444e-05 deg M 276.4782883453244 1.3087e-05 deg tp 2459380.096862886629 (2021-Jun-14.59686289) 6.0413e-05 TDB period 1636.159843133868 4.48 8.1816e-06 2.24e-08 d yr n .2200274022802461 1.1002e-09 deg/d Q 3.145686003887274 1.0487e-08 au   Orbit Determination Parameters    # obs. used (total)      3184      data-arc span      38630 days (105.76 yr)      first obs. used      1915-02-05      last obs. used      2020-11-10      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .41484      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 01:59:24   Additional Information  Earth MOID = 1.28808 au   Jupiter MOID = 2.29971 au   T_jup = 3.334  [ hide covariance matrix ] Orbital Elements at Epoch 2456370.5 (2013-Mar-19.0) TDB Reference: JPL 40 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1556591553002018 3.3578e-08   q 2.296153566183254 9.4094e-08 au tp 2456112.522464928140 (2012-Jul-04.02246493) 5.5234e-05 TDB node 140.7029883121298 3.3686e-05 deg peri 217.9963053847878 3.5576e-05 deg i 6.040209170476407 3.4918e-06 deg   Orbit Determination Parameters    # obs. used (total)      3184      data-arc span      38630 days (105.76 yr)      first obs. used      1915-02-05      last obs. used      2020-11-10      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .41484      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 01:59:24   Additional Information  Jupiter MOID = 2.29971 au   T_jup = 3.334  Orbit Covariance (6×6)   e q tp node peri i e 1.127455300248502E-15 -3.150263492567088E-15 -1.68368704436251E-13 2.106672224621387E-16 -2.052412452364139E-14 5.471030655783149E-17 q -3.150263492567088E-15 8.853723707335588E-15 5.371067751081433E-13 -6.75139846597134E-16 7.143602235988721E-14 -1.112445319411803E-16 tp -1.68368704436251E-13 5.371067751081433E-13 3.050826588796115E-9 2.346941873046195E-12 6.473600204013815E-10 4.229596652642955E-13 node 2.106672224621387E-16 -6.75139846597134E-16 2.346941873046195E-12 1.134759603620683E-9 -1.127693959312654E-9 1.951707945959358E-12 peri -2.052412452364139E-14 7.143602235988721E-14 6.473600204013815E-10 -1.127693959312654E-9 1.26568532919868E-9 -1.865523096317732E-12 i 5.471030655783149E-17 -1.112445319411803E-16 4.229596652642955E-13 1.951707945959358E-12 -1.865523096317732E-12 1.219243675731692E-11 [ 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 10.8   n/a MPO473780   diameter diameter 13.239 km 0.150 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   rotation period rot_per 19.9000 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Behrend, R. (2002) 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] [Chiorny, V.G.; Shevchenko, V.G.; Krugly, Yu.N.; Velichko, F.P.; Gaftonyuk, N.M. (2007) Planet. Space Sci. 55, 986-997.] [Oey, J. (2008) Minor Planet Bull. 35, 132-135.] [Durech, J.; Hanus, J.; Oszkiewsicz, D.; Vanco, R. (2016) Astron. Astrophys. 587, A48.] [Durech, J.; Hanus, J.; Broz, M.; Lehky, M.; et al. (2017) Icarus 304, 101-109.] geometric albedo albedo 0.636   0.050 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   B-V BV 0.689   0.050 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=12.00, mean=18.10, max.=24.21) deg. U-B UB 0.233   0.093 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=12.00, mean=18.10, max.=24.21) deg. Tholen spectral type spec_T E   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo SMASSII spectral type spec_B X   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) 1251 Hedera (1933 BE)          Discovered 1933-Jan-25 by Reinmuth, K. at Heidelberg Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1933 BE = 1929 CD1 = 1931 TJ2 = 1975 NW1 = A907 GD = A915 CA  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-25 13:24 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin