+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   15520 (1999 XK98) Classification: Main-belt Asteroid          SPK-ID: 2015520 [ 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 44 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1282340967835705 2.2865e-08   a 2.654725973159441 1.0391e-08 au q 2.314299585783454 6.0946e-08 au i 11.69142156611501 1.0318e-06 deg node 263.031795051029 3.7819e-06 deg peri 322.3899580760893 1.0865e-05 deg M 176.4536729326524 8.182e-06 deg tp 2458426.116345960993 (2018-Nov-03.61634596) 3.3612e-05 TDB period 1579.89409243096 4.33 9.2755e-06 2.539e-08 d yr n .2278633749722256 1.3378e-09 deg/d Q 2.995152360535426 1.1723e-08 au   Orbit Determination Parameters    # obs. used (total)      2510      data-arc span      14851 days (40.66 yr)      first obs. used      1980-07-12      last obs. used      2021-03-10      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .4387      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 01:00:46   Additional Information  Earth MOID = 1.31353 au   Jupiter MOID = 2.06765 au   T_jup = 3.347  [ 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 12.77   n/a E2021B10   diameter diameter 8.641 km 0.165 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 8.7904 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Clark, M. (2016) Minor Planet Bull. 43, 132-135.] geometric albedo albedo 0.237   0.030 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   15520 (1999 XK98)          Discovered 1999-Dec-07 by LINEAR at Socorro Reference: 20000621/Numbers.arc Last Updated: 2004-04-19 [ show close-approach data ] Alternate Designations  1999 XK98 = 1990 VX11 = 1993 MM = 1998 QF90  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-14 09:58 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin