+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1213 Algeria (1931 XD) Classification: Main-belt Asteroid          SPK-ID: 2001213 [ 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 43 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .128149714207276 3.4985e-08   a 3.136811814266569 1.3752e-08 au q 2.734830276746301 1.1031e-07 au i 13.10848722476631 4.0065e-06 deg node 271.2951203212349 1.8422e-05 deg peri 110.2912055246059 2.5298e-05 deg M 54.78511137634993 1.639e-05 deg tp 2458891.690130049091 (2020-Feb-12.19013005) 9.2498e-05 TDB period 2029.229299519478 5.56 1.3345e-05 3.654e-08 d yr n .1774072551018498 1.1667e-09 deg/d Q 3.538793351786837 1.5515e-08 au   Orbit Determination Parameters    # obs. used (total)      2707      data-arc span      32575 days (89.19 yr)      first obs. used      1931-11-16      last obs. used      2021-01-22      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .37464      source      ORB      producer      Otto Matic      solution date      2021-Feb-24 00:53:34   Additional Information  Earth MOID = 1.77244 au   Jupiter MOID = 1.99628 au   T_jup = 3.159  [ 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 11.18   n/a E2021B10   diameter diameter 29.175 km 0.251 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 16.3722 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Behrend, R. (2002) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2019) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] geometric albedo albedo 0.057   0.010 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   1213 Algeria (1931 XD)          Discovered 1931-Dec-05 by Reiss, G. at Algiers Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Feb-27 04:47 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin