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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 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 32 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2373136319102141 3.6572e-08  
a 2.347372022775341 7.3952e-09 au
q 1.790308642606099 8.4774e-08 au
i 23.38298749309499 4.3054e-06 deg
node 105.3068708523852 1.0007e-05 deg
peri 54.42360048243458 1.3162e-05 deg
M 221.8959070930752 1.0474e-05 deg
tp 2459704.435973942347
(2022-May-04.93597394)
3.9584e-05 TDB
period 1313.624721763394
3.60
6.2077e-06
1.7e-08
d
yr
n .274050871634587 1.2951e-09 deg/d
Q 2.904435402944583 9.1502e-09 au
  Orbit Determination Parameters
   # obs. used (total)      1954  
   data-arc span      32513 days (89.02 yr)  
   first obs. used      1932-01-10  
   last obs. used      2021-01-15  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .38026  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 00:57:09  

Additional Information
 Earth MOID = .877538 au 
 Jupiter MOID = 2.34313 au 
 T_jup = 3.414 
[ show covariance matrix ]

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 12.82   n/a E2021B10  
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. 2020-October); 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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