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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 ]

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For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.


Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 38 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2044587633823079 3.9856e-08  
a 2.740190069702987 1.0635e-08 au
q 2.179934196619034 1.1002e-07 au
i 17.28808591256681 4.7018e-06 deg
node 72.72446993419598 1.4064e-05 deg
peri 127.0702958448532 1.7635e-05 deg
M 94.81482888706623 1.1e-05 deg
tp 2458764.141717292835
(2019-Oct-07.64171729)
4.9743e-05 TDB
period 1656.79760875472
4.54
9.6458e-06
2.641e-08
d
yr
n .2172866487117776 1.265e-09 deg/d
Q 3.300445942786939 1.281e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2421  
   data-arc span      32058 days (87.77 yr)  
   first obs. used      1933-02-18  
   last obs. used      2020-11-26  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .38545  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 00:55:47  

Additional Information
 Earth MOID = 1.21599 au 
 Jupiter MOID = 1.82149 au 
 T_jup = 3.255 
[ hide covariance matrix ]
Orbital Elements at Epoch 2456758.5 (2014-Apr-11.0) TDB
Reference: JPL 38 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2043541481517561 3.9764e-08  
q 2.179836296194171 1.0952e-07 au
tp 2457106.395850718934
(2015-Mar-24.89585072)
4.7278e-05 TDB
node 72.82096450258408 1.4038e-05 deg
peri 126.5955519398887 1.7644e-05 deg
i 17.30814054146862 4.7058e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      2421  
   data-arc span      32058 days (87.77 yr)  
   first obs. used      1933-02-18  
   last obs. used      2020-11-26  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .38545  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 00:55:47  

Additional Information
 Jupiter MOID = 1.82149 au 
 T_jup = 3.255 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.581188478992723E-15 -4.342288302618686E-15 1.60754756122315E-13 -3.535965601051741E-15 7.764296734984516E-14 -2.643229077793162E-15
q -4.342288302618686E-15 1.199399865336224E-14 -3.652067606160625E-13 1.079992321237614E-14 -2.020563824243776E-13 7.433261992255084E-15
tp 1.60754756122315E-13 -3.652067606160625E-13 2.235165732491849E-9 -9.550744650903244E-12 5.199989864982343E-10 3.702187451124034E-12
node -3.535965601051741E-15 1.079992321237614E-14 -9.550744650903244E-12 1.970660554308909E-10 -1.898754332770766E-10 -5.747178078091699E-12
peri 7.764296734984516E-14 -2.020563824243776E-13 5.199989864982343E-10 -1.898754332770766E-10 3.113189976154293E-10 6.158170491896587E-12
i -2.643229077793162E-15 7.433261992255084E-15 3.702187451124034E-12 -5.747178078091699E-12 6.158170491896587E-12 2.214409211061532E-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 10.99   n/a E2021B10  
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.DBLast 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 1.82200116167112 1.82200069747644 1.82200162586818 3.90978433333272 3.78901595144489 2429937.218492127 1.17782801229803 193.50502152829 17.3355959090668 -86.6872756328815 2336852.47894436 T 38 CATAB v2.0f-lin.ifort 2021-Feb-24 00:55:53 2021-Feb-24 00:55
1999-May-26 12:38 < 00:01 Jupiter 1.9032434986608 1.90324296861434 1.90324402870727 2.85355879733443 2.69308644990907 2451325.026635978 0.366925207834028 181.242907664958 24.5494306986077 -84.6660913835105 2277128.93666926 T 38 CATAB v2.0f-lin.ifort 2021-Feb-24 00:55:53 2021-Feb-24 00:55
2036-Mar-03 07:11 < 00:01 Jupiter 1.88546954472356 1.88546910730456 1.88546998214396 4.387723840522 4.28411562365277 2464755.799352489 0.376699298570998 123.455636697284 13.077253081173 -82.6284578932418 3114276.62291141 T 38 CATAB v2.0f-lin.ifort 2021-Feb-24 00:55:53 2021-Feb-24 00:55
2094-Oct-08 21:03 00:01 Jupiter 1.81876352780059 1.81876300539539 1.81876405020589 3.67460137335343 3.54559846663592 2486159.377084112 1.31418254685056 157.869061385252 27.8388251381708 87.8473097401012 2122150.49081731 T 38 CATAB v2.0f-lin.ifort 2021-Feb-24 00:55:53 2021-Feb-24 00:55
2153-Apr-15 00:53 00:03 Jupiter 1.9936429453263 1.99364133366122 1.99364455713937 2.41372201019892 2.23076905073166 2507531.536805009 2.75230177173456 1028.39808782405 42.6346444997284 -81.447237086703 2419109.83508685 T 38 CATAB v2.0f-lin.ifort 2021-Feb-24 00:55:53 2021-Feb-24 00:55
2190-Feb-08 04:21 00:03 Jupiter 1.81041827013906 1.81041755714811 1.81041898315717 4.18463068788941 4.07129141018343 2520979.681150927 2.70061686102378 409.292187346789 15.5279182467124 -86.3739478177192 2592050.1418297 T 38 CATAB v2.0f-lin.ifort 2021-Feb-24 00:55:53 2021-Feb-24 00:55

Alternate Designations
 1938 HC = 1933 DH = A911 KC 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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