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18 Melpomene
Classification: Main-belt Asteroid          SPK-ID: 2000018
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2457600.5 (2016-Jul-31.0) TDB
Reference: JPL 93 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2189506831697914 2.6706e-08  
a 2.295482538435649 2.1014e-09 au
q 1.792885068440837 6.1136e-08 au
i 10.13359507332565 3.4912e-06 deg
node 150.4701221646739 1.8122e-05 deg
peri 227.8519211785859 1.9374e-05 deg
M 343.9451947154129 7.6452e-06 deg
tp 2457657.151571168592
2.7012e-05 JED
period 1270.30912298091
n .2833955873317064 3.8915e-10 deg/d
Q 2.798080008430461 2.5615e-09 au
  Orbit Determination Parameters
   # obs. used (total)      4661  
   data-arc span      58270 days (159.53 yr)  
   first obs. used      1856-09-26  
   last obs. used      2016-04-10  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-BIG16  
   condition code      0  
   fit RMS      .42136  
   data source      ORB  
   producer      Otto Matic  
   solution date      2016-Apr-25 12:24:39  

Additional Information
 Earth MOID = .809013 au 
 Jupiter MOID = 2.68823 au 
 T_jup = 3.543 
[ show covariance matrix ]

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 6.51 mag n/a IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 15
magnitude slope G 0.25   n/a PDS3 (MPC 17257) Fit
diameter diameter 140.57 km 2.8 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 15
rotation period rot_per 11.570 h n/a LCDB (Rev. 2016-February); Warner et al., 2009 Published Reference List:
[Binzel, R.P.; Harris, A.W. (1980) Icarus 42, 43-45.]
[Zeigler, K.W.; Florence, W.B. (1985) Icarus 62, 512-517.]
[Lagerkvist, C.I.; Magnusson, P.; Williams, I.P.; Buontempo, M.E.; et al. (1988) Astron. Astrophys. Suppl. Ser. 73, 395-405.]
[Hoffmann, M.; Geyer, E.H. (1990) in Asteroids, Comets, Meteors III. C.-I. Lagerkvist, H. Rickman, B.A. Lindblad, M. Lindgren, eds. Uppsala, p. 111-114.]
[Torppa, J.; Kaasalainen, M.; Michalowski, T.; Kwiatkowski, T.; et al. (2003) Icarus 164, 346-383.]
[Behrend, R. (2011) Observatoire de Geneve web site,]
[Pilcher, F. (2013) Minor Planet Bul. 40, 33.]
[Pilcher, F. (2014) Minor Planet Bul. 41, 155-156.]
[Hanus, J.; Durech, J.; Oszkiewicz, D.A.; Behrend, R.; et al. (2015) Astron. Astrophys. 586, A108.]
geometric albedo albedo 0.2225   0.009 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 15
B-V BV .854 mag .013 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=9; phase (min.=2.60, mean=19.31, max.=27.48) deg.
U-B UB .425 mag .041 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=8; phase (min.=2.60, mean=18.73, max.=27.48) deg.
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B S   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)

18 Melpomene          Discovered 1852-Jun-24 by Hind, J. R. at London
Reference: DISCOVERY.DBLast Updated: 2003-08-29
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]
FirstGov 2016-May-03 12:31 UT
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