+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   18372 (1991 RF16) Classification: Main-belt Asteroid          SPK-ID: 2018372 [ 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 27 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1374127614637655 3.5618e-08   a 2.632752302705258 1.1483e-08 au q 2.270978538540441 9.6333e-08 au i 4.064530536632306 4.5397e-06 deg node 62.82643814207521 5.1489e-05 deg peri 290.3635465088919 5.4131e-05 deg M 308.3141193582676 1.8416e-05 deg tp 2459424.517965323026 (2021-Jul-29.01796532) 8.0346e-05 TDB period 1560.319114523778 4.27 1.0208e-05 2.795e-08 d yr n .2307220341333029 1.5094e-09 deg/d Q 2.994526066870074 1.3061e-08 au   Orbit Determination Parameters    # obs. used (total)      1517      data-arc span      10556 days (28.90 yr)      first obs. used      1991-09-14      last obs. used      2020-08-08      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .50224      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 02:27:44   Additional Information  Earth MOID = 1.26811 au   Jupiter MOID = 2.44016 au   T_jup = 3.382  [ 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 14.22   n/a E2021B10   diameter diameter 4.500 km 0.082 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.138   0.011 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   18372 (1991 RF16)          Discovered 1991-Sep-15 by Holt, H. E. at Palomar Reference: 20001111/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1991 RF16 = 1997 AD21 = 1998 DF37  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-23 15:48 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin