+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1484 Postrema (1938 HC) Classification: Main-belt Asteroid          SPK-ID: 2001484 [ 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 37 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2039039532325345 3.9889e-08   a 2.739836532493444 1.0264e-08 au q 2.181173032307111 1.0965e-07 au i 17.2990401150193 4.7057e-06 deg node 72.76329440014617 1.4051e-05 deg peri 127.0394532062972 1.7656e-05 deg M 51.41037272868557 1.0942e-05 deg tp 2458763.944169421442 (2019-Oct-07.44416942) 4.9888e-05 TDB period 1656.476980972439 4.54 9.3079e-06 2.548e-08 d yr n .2173287067283368 1.2212e-09 deg/d Q 3.298500032679777 1.2356e-08 au   Orbit Determination Parameters    # obs. used (total)      2418      data-arc span      32048 days (87.74 yr)      first obs. used      1933-02-18      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .38562      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 02:00:55   Additional Information  Earth MOID = 1.21822 au   Jupiter MOID = 1.82456 au   T_jup = 3.256  [ 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 10.9   n/a MPO384761   diameter diameter 40.871 km 0.279 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 12.1923 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Behrend, R. (2006) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Julian, W.M. (2006) Minor Planet Bull. 33, 103-104.] [Durech, J.; Hanus, J.; Oszkiewsicz, D.; Vanco, R. (2016) Astron. Astrophys. 587, A48.] geometric albedo albedo 0.015   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   SMASSII spectral type spec_B B   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) 1484 Postrema (1938 HC)          Discovered 1938-Apr-29 by Neujmin, G. at Simeis Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ hide close-approach data ] Close-Approach Data   ...sorted by Date/Time (TDB) Date/Time (TDB) Time Uncertainty (days_HH:MM) Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified 1940-Nov-03 17:15 00:01 Jupiter 1.82200116218325 1.82200069789515 1.82200162647373 3.90978435627562 3.78901597515355 2429937.218492786 1.17797102334978 193.519297047646 17.3421973094882 -86.6872557627744 2335940.44485657 T 37 CATAB v2.0f-lin.ifort 2020-Dec-18 02:01:00 2020-Dec-18 02:01 1999-May-26 12:38 < 00:01 Jupiter 1.90324349929024 1.90324296913873 1.90324402944176 2.85355916042424 2.69308683468888 2451325.026657846 0.366961476037562 181.338009617833 24.5498600988146 -84.6673875810127 2275966.66576831 T 37 CATAB v2.0f-lin.ifort 2020-Dec-18 02:01:00 2020-Dec-18 02:01 2036-Mar-03 07:11 < 00:01 Jupiter 1.88546954525583 1.88546910756985 1.8854699829432 4.38772389665945 4.28411568117746 2464755.799357072 0.376829919467111 123.53201077867 13.0798799224837 -82.6264692654811 3112602.79172858 T 37 CATAB v2.0f-lin.ifort 2020-Dec-18 02:01:00 2020-Dec-18 02:01 2094-Oct-08 21:03 00:01 Jupiter 1.81876352860876 1.81876300616821 1.81876405104952 3.67460146179982 3.54559855835871 2486159.377089449 1.3144859406155 157.970909362949 27.8412064183653 87.8521145253081 2121086.37690311 T 37 CATAB v2.0f-lin.ifort 2020-Dec-18 02:01:00 2020-Dec-18 02:01 2153-Apr-15 00:53 00:03 Jupiter 1.99364294614697 1.99364133424596 1.99364455819599 2.41372229300113 2.23076935680584 2507531.536823353 2.75289020254175 1028.53825778498 42.6592163401499 -81.4469679871337 2417874.38386185 T 37 CATAB v2.0f-lin.ifort 2020-Dec-18 02:01:00 2020-Dec-18 02:01 2190-Feb-08 04:21 00:03 Jupiter 1.8104182706757 1.81041755728114 1.81041898409743 4.18463070473708 4.07129142753419 2520979.681151545 2.70116141873477 409.428882704581 15.532637642461 -86.3725889946062 2590881.1746869 T 37 CATAB v2.0f-lin.ifort 2020-Dec-18 02:01:00 2020-Dec-18 02:01 Alternate Designations  1938 HC = 1933 DH = A911 KC  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-21 09:39 UT (server date/time)   Site Manager:   Ryan S. 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