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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 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 34 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2374005837467185 1.1606e-08  
a 2.347428968157123 6.8818e-09 au
q 1.790147960812665 2.6583e-08 au
i 23.38294570786422 6.8513e-07 deg
node 105.3063496536401 1.3795e-06 deg
peri 54.40867951442305 2.6918e-06 deg
M 275.6381734142424 3.4493e-06 deg
tp 2459704.343926668029
(2022-May-04.84392667)
1.3815e-05 TDB
period 1313.672523292667
3.60
5.7768e-06
1.582e-08
d
yr
n .2740408995521005 1.2051e-09 deg/d
Q 2.904709975501581 8.5155e-09 au
  Orbit Determination Parameters
   # obs. used (total)      1982  
   data-arc span      32513 days (89.02 yr)  
   first obs. used      1932-01-10  
   last obs. used      2021-01-15  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .38058  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-12 12:45:41  

Additional Information
 Earth MOID = .877981 au 
 Jupiter MOID = 2.34272 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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