+ 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 38 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1576141766033623 3.3904e-08   a 2.717387261510959 9.1397e-09 au q 2.289088505775443 9.5145e-08 au i 6.049925720404793 3.5428e-06 deg node 140.6285587187577 3.4133e-05 deg peri 217.1328482560981 3.5938e-05 deg M 276.4782871478889 1.3152e-05 deg tp 2459380.096868554989 (2021-Jun-14.59686856) 6.0729e-05 TDB period 1636.159844108631 4.48 8.2547e-06 2.26e-08 d yr n .2200274021491621 1.1101e-09 deg/d Q 3.145686017246474 1.058e-08 au   Orbit Determination Parameters    # obs. used (total)      3057      data-arc span      38534 days (105.50 yr)      first obs. used      1915-02-05      last obs. used      2020-08-06      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .42112      source      ORB      producer      Otto Matic      solution date      2020-Aug-24 22:30:45   Additional Information  Earth MOID = 1.28808 au   Jupiter MOID = 2.29971 au   T_jup = 3.334  [ hide covariance matrix ] Orbital Elements at Epoch 2456261.5 (2012-Nov-30.0) TDB Reference: JPL 38 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1553208996482657 3.3942e-08   q 2.296195842612375 9.4805e-08 au tp 2456112.299075894694 (2012-Jul-03.79907589) 5.5452e-05 TDB node 140.7257747018993 3.4226e-05 deg peri 217.9188108720346 3.6087e-05 deg i 6.039842485773367 3.5371e-06 deg   Orbit Determination Parameters    # obs. used (total)      3057      data-arc span      38534 days (105.50 yr)      first obs. used      1915-02-05      last obs. used      2020-08-06      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .42112      source      ORB      producer      Otto Matic      solution date      2020-Aug-24 22:30:45   Additional Information  Jupiter MOID = 2.29971 au   T_jup = 3.334  Orbit Covariance (6×6)   e q tp node peri i e 1.152039393795047E-15 -3.208239910742409E-15 -1.476146062346691E-13 3.823984765522687E-16 -1.784970863389753E-14 1.191358475147907E-16 q -3.208239910742409E-15 8.987894629919734E-15 4.854379313222867E-13 -3.854109736699447E-16 6.417071712803784E-14 -1.735177309221175E-16 tp -1.476146062346691E-13 4.854379313222867E-13 3.074970952672057E-9 3.460102807553759E-12 6.504305279395676E-10 5.664427520225709E-13 node 3.823984765522687E-16 -3.854109736699447E-16 3.460102807553759E-12 1.171401217208442E-9 -1.1638819510279E-9 5.35468728811919E-12 peri -1.784970863389753E-14 6.417071712803784E-14 6.504305279395676E-10 -1.1638819510279E-9 1.302260005029858E-9 -5.222280129762748E-12 i 1.191358475147907E-16 -1.735177309221175E-16 5.664427520225709E-13 5.35468728811919E-12 -5.222280129762748E-12 1.251078417689739E-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. 2019-August); 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 ] 2020-Sep-24 07:23 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin