+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   16000 Neilgehrels (1999 AW16) Classification: Main-belt Asteroid          SPK-ID: 2016000 [ 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 37 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1672057655733091 3.4554e-08   a 2.403242355452618 7.1725e-09 au q 2.001406377550961 8.2846e-08 au i 2.187572533789236 4.8268e-06 deg node 174.7995952710966 8.1182e-05 deg peri 50.80926080516652 8.2278e-05 deg M 232.42235872669 1.402e-05 deg tp 2459682.744017623634 (2022-Apr-13.24401762) 5.3788e-05 TDB period 1360.801505748078 3.73 6.092e-06 1.668e-08 d yr n .264549971821273 1.1843e-09 deg/d Q 2.805078333354276 8.3718e-09 au   Orbit Determination Parameters    # obs. used (total)      1607      data-arc span      10551 days (28.89 yr)      first obs. used      1992-03-25      last obs. used      2021-02-12      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .49996      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 01:15:53   Additional Information  Earth MOID = .991825 au   Jupiter MOID = 2.17447 au   T_jup = 3.504  [ 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 14.7   n/a MPO449067   diameter diameter 2.729 km 0.510 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.343   0.121 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   16000 Neilgehrels           Discovered 1999 Jan. 10 by Spacewatch at Kitt Peak. Neil Gehrels (1952) is an astrophysicist who has worked to develop gamma-ray astronomy into a full astronomical discipline. He is the Principal Investigator for the Swift Gamma-Ray Burst Mission (launched Nov. 2004) and was Project Scientist for the Compton Gamma Ray Observatory (1991-2000). NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: MPC batch dated 2015-03-05 Last Updated: 2015-03-09 Alternate Designations  1999 AW16 = 1992 GL1 = 1993 RK17  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-20 02:17 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin