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385 Ilmatar (A894 EA)
Classification: Main-belt Asteroid          SPK-ID: 2000385
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 108 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1246427649142289 1.7466e-08  
a 2.850103035710216 6.2913e-09 au
q 2.494858313048857 4.7089e-08 au
i 13.58063881037137 4.5267e-07 deg
node 344.8549226374612 2.5083e-06 deg
peri 188.9646212130534 6.7419e-06 deg
M 173.2323240923833 5.7552e-06 deg
tp 2458550.801229656780
(2019-Mar-08.30122966)
2.7075e-05 TDB
period 1757.475453375536
4.81
5.8192e-06
1.593e-08
d
yr
n .2048392763088427 6.7824e-10 deg/d
Q 3.205347758371574 7.0755e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2543  
   data-arc span      46542 days (127.43 yr)  
   first obs. used      1894-03-05  
   last obs. used      2021-08-08  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .48754  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-25 06:33:30  

Additional Information
 Earth MOID = 1.50227 au 
 Jupiter MOID = 1.77451 au 
 T_jup = 3.253 
[ hide covariance matrix ]
Orbital Elements at Epoch 2456965.5 (2014-Nov-04.0) TDB
Reference: JPL 108 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1223974890533538 1.7437e-08  
q 2.500977245810455 4.7041e-08 au
tp 2456785.656241986607
(2014-May-08.15624199)
2.6369e-05 TDB
node 345.025044624581 2.5202e-06 deg
peri 187.6765375295955 6.8757e-06 deg
i 13.55170262745833 4.5167e-07 deg
  Orbit Determination Parameters
   # obs. used (total)      2543  
   data-arc span      46542 days (127.43 yr)  
   first obs. used      1894-03-05  
   last obs. used      2021-08-08  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .48754  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-25 06:33:30  

Additional Information
 Jupiter MOID = 1.77451 au 
 T_jup = 3.253 
Orbit Covariance (6×6)
  e q tp node peri i
e 3.04057458144201E-16 -8.164834757824751E-16 3.500910250548376E-14 -8.717934200054775E-15 -5.087557982853171E-15 9.593364194325071E-16
q -8.164834757824751E-16 2.21287657885833E-15 -7.777165952606323E-14 2.203200123338071E-14 1.834390495147877E-14 -2.67921836801162E-15
tp 3.500910250548376E-14 -7.777165952606323E-14 6.953265732568279E-10 -3.511272116758813E-11 1.746010285981752E-10 6.473985151100489E-13
node -8.717934200054775E-15 2.203200123338071E-14 -3.511272116758813E-11 6.351202276806035E-12 -1.162037472462776E-11 5.341063158362051E-13
peri -5.087557982853171E-15 1.834390495147877E-14 1.746010285981752E-10 -1.162037472462776E-11 4.727565125342407E-11 -3.55892401960439E-13
i 9.593364194325071E-16 -2.67921836801162E-15 6.473985151100489E-13 5.341063158362051E-13 -3.55892401960439E-13 2.040093897589157E-13

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 7.6   n/a MPO473766 IRAS observations used: 24
diameter diameter 85.837 km 0.576 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
rotation period rot_per 62.35 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Zeigler, K.W.; Florence, W.B.; Blanco, E.J.; McGaughey, J. (1986) Minor Planet Bull. 13, 25-26.]
geometric albedo albedo 0.242   0.042 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
B-V BV 0.847   0.073 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=5.60, mean=15.13, max.=22.96) deg.
U-B UB 0.370   0.026 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=3; phase (min.=5.60, mean=14.98, max.=22.96) deg.
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices

385 Ilmatar (A894 EA)          Discovered 1894-Mar-01 by Wolf, M. at Heidelberg
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 A894 EA = 1942 FQ = 1953 TQ = 1987 QG3 = A918 CC 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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