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8516 Hyakkai (1991 TW1)
Classification: Main-belt Asteroid          SPK-ID: 2008516
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 40 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1625073716978196 2.417e-08  
a 2.755607934117062 9.8961e-09 au
q 2.30780133131404 6.6825e-08 au
i 5.86182591194292 7.1481e-07 deg
node 51.42973729013472 6.7773e-06 deg
peri 347.4727158036561 7.8794e-06 deg
M 124.8585076455633 5.0756e-06 deg
tp 2458621.017659323903
(2019-May-17.51765932)
2.1613e-05 TDB
period 1670.800384989287
4.57
9.0004e-06
2.464e-08
d
yr
n .2154655955518638 1.1607e-09 deg/d
Q 3.203414536920084 1.1504e-08 au
  Orbit Determination Parameters
   # obs. used (total)      3431  
   data-arc span      17260 days (47.26 yr)  
   first obs. used      1973-12-20  
   last obs. used      2021-03-23  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .39936  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-May-03 23:58:19  

Additional Information
 Earth MOID = 1.3151 au 
 Jupiter MOID = 2.21291 au 
 T_jup = 3.317 
[ 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 13.33   n/a E2021B10  
rotation period rot_per 4.80153 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:
[McNeill, A.; Mommert, M.; Trilling, D.E.; Llama, J.; Skiff, B. (2019) Ap. J. Suppl. Series 245, id.29.]
[Pal, A.; Szakats, R.; Kiss, C.; Bodi, A.; et al. (2019) Ap. J. Supl. Ser. 247, id.26.]
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)

8516 Hyakkai           Discovered 1991 Oct. 13 by T. Hioki and S. Hayakawa at Okutama.
Masaaki Hyakkai (b. 1963) is a science teacher and president of Gunma Astronomical Society. As a volunteer lecturer at astronomical observation meetings, he works to popularize science and astronomy.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20040107/MPCPages.arcLast Updated: 2004-01-07

Alternate Designations
 1991 TW1 = 1973 YL1 = 1977 RD1 = 1988 BF1 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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