+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1802 Zhang Heng (1964 TW1) Classification: Main-belt Asteroid          SPK-ID: 2001802 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 42 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .0348790497435947 1.1124e-08   a 2.846560159702198 9.2741e-09 au q 2.74727484629381 3.3929e-08 au i 2.691620778040098 7.9725e-07 deg node 142.5336211570074 2.2788e-05 deg peri 295.9258861279078 4.1494e-05 deg M 238.4384398202257 3.6723e-05 deg tp 2459988.842292104948 (2023-Feb-13.34229210) 0.0001802 TDB period 1754.199475906868 4.80 8.5728e-06 2.347e-08 d yr n .2052218148189167 1.0029e-09 deg/d Q 2.945845473110586 9.5976e-09 au   Orbit Determination Parameters    # obs. used (total)      3339      data-arc span      26266 days (71.91 yr)      first obs. used      1949-07-28      last obs. used      2021-06-26      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .41842      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 12:49:00   Additional Information  Earth MOID = 1.76391 au   Jupiter MOID = 2.13 au   T_jup = 3.305  [ 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 11.75   n/a E2021B10   diameter diameter 13.333 km 0.110 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 3.161 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Simpson, G.; Chong, E.; Gerhardt, M.; Gorsky, S.; et al. (2013) Minor Planet Bull. 146-151.] [Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.] [Mannucci, M.; Montigiani, N. (2019) Minor Planet Bull. 46, 277-278.] [Carreño, A.; Fornas, G.; Arce, E.; Mas, V. (2020) Minor Planet Bull. 47, 7-10.] [Erasmus, N.; Navarro-Meza, S.; McNeill, A.; Trilling, D.E.; et al. (2020) Ap. J. Suppl. Ser. 247, A13.] geometric albedo albedo 0.228   0.026 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   1802 Zhang Heng (1964 TW1)          Discovered 1964-Oct-09 by Purple Mountain Observatory at Nanking Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  1964 TW1 = 1933 FH = 1936 YB = 1938 EB1 = 1948 JN = 1949 OV = 1955 YB = 1972 JX  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jul-29 08:31 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin