+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   19727 Allen (1999 XS2) Classification: Main-belt Asteroid          SPK-ID: 2019727 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: MPO253501 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.1871812 n/a   a 2.4344828 n/a AU q 1.9787934 n/a AU i 13.35808 n/a deg node 253.19333 n/a deg peri 324.98048 n/a deg M 8.83406 n/a deg tp 2456366.4539802 (2013-Mar-14.95398020) n/a JED period 1387.4217653 3.80 n/a n/a d yr n 0.25947409 n/a deg/d Q 2.8901722 n/a AU   Orbit Determination Parameters    # obs. used (total)      698      first obs. used      1986-??-??      last obs. used      2013-01-26      # oppositions      16      planetary ephem.      DE403      condition code      0      fit RMS      0.51      data source      MPC:mpn      producer      MPCLINUX   Additional Information  T_jup = 3.445  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 13.2 mag n/a PDS3 (MPO 6638)   19727 Allen           Discovered 1999 Dec. 4 by C. W. Juels at Fountain Hills. London-based solar physicist Clabon Walter Allen (1904-1987) authored the first (1955) through third (1973) editions of Astrophysical Quantities, without which most professional astronomers would never have received their degrees, and most watchers of the sky would never have successfully completed their observing sessions. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20060613/MPCPages.arc Last Updated: 2008-05-22 Alternate Designations  1999 XS2 = 1994 LK4  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-Jun-19 12:26 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin