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1495 Helsinki (1938 SW)
Classification: Main-belt Asteroid          SPK-ID: 2001495
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 44 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1556104130624051 3.4735e-08  
a 2.638164281030505 9.0892e-09 au
q 2.227638447532865 9.1389e-08 au
i 12.72490388406304 4.1364e-06 deg
node 13.07871227297948 1.6681e-05 deg
peri 268.3849107242542 2.1389e-05 deg
M 131.6471458891577 1.4544e-05 deg
tp 2458628.152054622059
(2019-May-24.65205462)
6.2536e-05 TDB
period 1565.132756539527
4.29
8.0885e-06
2.215e-08
d
yr
n .2300124372810086 1.1887e-09 deg/d
Q 3.048690114528145 1.0504e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2726  
   data-arc span      32912 days (90.11 yr)  
   first obs. used      1930-12-13  
   last obs. used      2021-01-21  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .37466  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 00:55:52  

Additional Information
 Earth MOID = 1.25447 au 
 Jupiter MOID = 2.21586 au 
 T_jup = 3.345 
[ show covariance matrix ]

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 11.55   n/a E2021B10  
diameter diameter 12.235 km 0.059 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
rotation period rot_per 5.33116 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]
[Oey, J.; Behrend, R.; Pravec, P.; Teng, J.P.; et al. (2007) Minor Planet Bull. 34, 2.]
[Hanus, J.; Durech, J.; Broz, M.; Marciniak, A.; et al. (2013) Astron. Astrophys. 551, A67.]
geometric albedo albedo 0.274   0.049 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  

1495 Helsinki (1938 SW)          Discovered 1938-Sep-21 by Vaisala, Y. at Turku
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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