+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21860 Joannaguy (1999 TX180) Classification: Main-belt Asteroid          SPK-ID: 2021860 [ 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 31 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .03173958125656873 3.2638e-08   a 2.686186374448182 1.1826e-08 au q 2.600927943746096 8.8331e-08 au i 3.317348386389761 3.6483e-06 deg node 123.6535434828864 6.6225e-05 deg peri 327.1261792448765 0.00010011 deg M 249.2993038154768 7.7709e-05 deg tp 2459694.982004351232 (2022-Apr-25.48200435) 0.00034874 TDB period 1608.06144588033 4.40 1.0619e-05 2.907e-08 d yr n .2238720422794035 1.4784e-09 deg/d Q 2.771444805150268 1.2201e-08 au   Orbit Determination Parameters    # obs. used (total)      1887      data-arc span      10485 days (28.71 yr)      first obs. used      1992-02-26      last obs. used      2020-11-10      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .51388      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 03:18:04   Additional Information  Earth MOID = 1.61804 au   Jupiter MOID = 2.27303 au   T_jup = 3.371  [ 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 13.97   n/a E2021B10   diameter diameter 4.796 km 0.106 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.232   0.037 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   21860 Joannaguy           Discovered 1999 Oct. 10 by the Lincoln Laboratory Near-Earth Asteroid Research Team at Socorro. Joanna Christine Guy (b. 1991) is a finalist in the 2005 Discovery Channel Young Scientist Challenge (DCYSC), a middle school science competition, for her behavioral science project. She attends the Southern Middle School, Oakland, Maryland. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20051019/MPCPages.arc Last Updated: 2005-10-26 Alternate Designations  1999 TX180 = 1992 DQ13 = 1998 MU6  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-13 06:09 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin