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1657 Roemera (1961 EA)
Classification: Main-belt Asteroid          SPK-ID: 2001657
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 29 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .236996702507974 3.6643e-08  
a 2.347937478850843 7.4496e-09 au
q 1.791484038668308 8.4938e-08 au
i 23.38325173620439 4.3951e-06 deg
node 105.3082740473336 1.0011e-05 deg
peri 54.43773646571544 1.3249e-05 deg
M 167.0632817088899 1.0385e-05 deg
tp 2458390.672890510984
(2018-Sep-29.17289051)
3.6496e-05 TDB
period 1314.099406945647
3.60
6.2541e-06
1.712e-08
d
yr
n .2739518776868986 1.3038e-09 deg/d
Q 2.904390919033379 9.2152e-09 au
  Orbit Determination Parameters
   # obs. used (total)      1846  
   data-arc span      32431 days (88.79 yr)  
   first obs. used      1932-01-10  
   last obs. used      2020-10-25  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .3821  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 04:16:44  

Additional Information
 Earth MOID = .878791 au 
 Jupiter MOID = 2.3436 au 
 T_jup = 3.414 
[ hide covariance matrix ]
Orbital Elements at Epoch 2457211.5 (2015-Jul-08.0) TDB
Reference: JPL 29 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2362969420288761 3.6637e-08  
q 1.793359686572701 8.4876e-08 au
tp 2457075.140070161733
(2015-Feb-21.64007016)
3.4235e-05 TDB
node 105.3359274537887 1.0014e-05 deg
peri 54.33248455868463 1.3277e-05 deg
i 23.37686572547975 4.3942e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      1846  
   data-arc span      32431 days (88.79 yr)  
   first obs. used      1932-01-10  
   last obs. used      2020-10-25  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .3821  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 04:16:44  

Additional Information
 Jupiter MOID = 2.3436 au 
 T_jup = 3.414 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.342293206944141E-15 -3.103053297528628E-15 1.149663690104498E-13 -1.023673653063128E-15 2.445496185420756E-14 -1.05542036809593E-15
q -3.103053297528628E-15 7.203913174071986E-15 -2.088743623804851E-13 1.831611511217977E-15 -4.199861089877836E-14 3.005347182749631E-15
tp 1.149663690104498E-13 -2.088743623804851E-13 1.172004340123506E-9 8.243156660715966E-14 3.124355834066573E-10 8.983123751096544E-13
node -1.023673653063128E-15 1.831611511217977E-15 8.243156660715966E-14 1.002749767827502E-10 -9.164123378385749E-11 -7.388409581058975E-13
peri 2.445496185420756E-14 -4.199861089877836E-14 3.124355834066573E-10 -9.164123378385749E-11 1.762894432309858E-10 9.821535262836597E-13
i -1.05542036809593E-15 3.005347182749631E-15 8.983123751096544E-13 -7.388409581058975E-13 9.821535262836597E-13 1.930864821763808E-11

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 12.8   n/a MPO492769  
diameter diameter 7.665 km 0.219 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
rotation period rot_per 34.0 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so.
Published Reference List:
[Warner, B.D. (2009) Minor Planet Bull. 36, 7-13.]
geometric albedo albedo 0.220   0.030 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices

1657 Roemera (1961 EA)          Discovered 1961-Mar-06 by Wild, P. at Zimmerwald
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1961 EA = 1932 AB 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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