+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21474 Pamelatsai (1998 HO99) Classification: Main-belt Asteroid          SPK-ID: 2021474 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 21 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .08614122382676151 3.7144e-08   a 2.377370881846481 9.9144e-09 au q 2.172581244594117 8.9799e-08 au i 6.382036215272104 5.0152e-06 deg node 185.1140115377301 3.2465e-05 deg peri 75.54427302959746 4.5523e-05 deg M 28.63098894925694 2.9868e-05 deg tp 2459094.017636030907 (2020-Sep-01.51763603) 0.00011131 TDB period 1338.886725038133 3.67 8.3753e-06 2.293e-08 d yr n .2688801026014704 1.682e-09 deg/d Q 2.582160519098844 1.0768e-08 au   Orbit Determination Parameters    # obs. used (total)      956      data-arc span      9620 days (26.34 yr)      first obs. used      1994-03-14      last obs. used      2020-07-15      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .55116      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 03:46:02   Additional Information  Earth MOID = 1.16659 au   Jupiter MOID = 2.45709 au   T_jup = 3.527  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 15.71   n/a E2020-QM5   21474 Pamelatsai           Discovered 1998 Apr. 21 by the Lincoln Laboratory Near-Earth Asteroid Research Team at Socorro. Pamela Tsai mentored a finalist in the 2005 Intel Science Talent Search, a science competition for high school seniors. She teaches at the Monta Vista High School, Cupertino, California. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20050224/MPCPages.arc Last Updated: 2005-02-28 [ show close-approach data ] Alternate Designations  1998 HO99 = 1999 TS141  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-22 12:28 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin