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24 Themis
Classification: Main-belt Asteroid          SPK-ID: 2000024
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2457000.5 (2014-Dec-09.0) TDB
Reference: JPL 92 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1258089396666894 2.5709e-08  
a 3.134947262220447 7.7824e-09 AU
q 2.740542871249502 8.1074e-08 AU
i .7522721906473218 2.9327e-06 deg
node 35.92250485382481 0.00022625 deg
peri 106.6713065284752 0.00022658 deg
M 71.67401795563934 1.1768e-05 deg
tp 2456596.851785097262
(2013-Oct-31.35178510)
6.557e-05 JED
period 2027.420277385921
5.55
7.5495e-06
2.067e-08
d
yr
n .1775655516596541 6.612e-10 deg/d
Q 3.529351653191392 8.7615e-09 AU
  Orbit Determination Parameters
   # obs. used (total)      2272  
   data-arc span      59081 days (161.75 yr)  
   first obs. used      1853-04-27  
   last obs. used      2015-01-29  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-BIG16  
   condition code      0  
   fit RMS      .65401  
   data source      ORB  
   producer      Otto Matic  
   solution date      2015-Mar-09 13:25:10  

Additional Information
 Earth MOID = 1.75377 AU 
 T_jup = 3.200 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 7.08 mag n/a PDS3 (MPC 17257)  
magnitude slope G 0.19   n/a PDS3 (MPC 17257) Fit
diameter diameter 198 km n/a J.G. Williams (E-mail September 1990) based on IRTF albedo of 0.067
rotation period rot_per 8.374 h n/a LCDB (Rev. 2015-Feb); Warner et al., 2009 Published Reference List:
[Tedesco, E.F. (1979) PhD Dissertation, New. Mex. State Univ. 280pp.]
[Van Houten-Groeneveld, I.; van Houten, C.J.; Zappala, V. (1979) Astron. Astrophys. Suppl. Ser. 35, 223-232.]
[Harris, A.W.; Young, J.W. (1983) Icarus 54, 59-109.]
[Harris, A.W.; Young, J.W.; Bowell, E.; Martin, L.J.; et al. (1989) Icarus 77, 171-186.]
[Chiorny, V.G.; Shevchenko, V.G.; Krugly, Yu.N.; Velichko, F.P.; Gaftonyuk, N.M. (2007) Planet. Space Sci. 55, 986-997.]
[Ditteon, R.; Hawkins, S. (2007) Minor Planet Bul. 34, 59-64.]
[Higley, S.; Hardersen, P.; Dyvig, R. (2008) Minor Planet Bul. 35, 63-66.]
[Pilcher, F. (2012) http://aslc-nm.org/Pilcher.html]
[Pilcher, F. (2013) Minor Planet Bul. 40, 85-87.]
[Pilcher, F. (2014) Minor Planet Bul. 41, 250-252.]
geometric albedo albedo 0.067   n/a J.G. Williams (E-mail September 1990) IRTF
B-V BV .684 mag .030 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=10; phase (min.=.16, mean=9.29, max.=18.36) deg.
U-B UB .336 mag .024 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=8; phase (min.=.16, mean=8.75, max.=18.36) deg.
Tholen spectral type spec_T C   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B B   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)

24 Themis          Discovered 1853-Apr-05 by De Gasparis, A. at Naples
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 1947 BA = 1955 OH 
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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