+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   140 Siwa (A874 TB) Classification: Main-belt Asteroid          SPK-ID: 2000140 [ 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 158 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2141284549362081 2.3655e-08   a 2.734804914256906 6.9613e-09 au q 2.149205363415126 6.2438e-08 au i 3.185459244696143 1.6196e-06 deg node 107.1772417351927 1.6657e-05 deg peri 196.8536304968357 1.6987e-05 deg M 189.2790942825894 7.0197e-06 deg tp 2459983.879422830914 (2023-Feb-08.37942283) 3.418e-05 TDB period 1651.915979674704 4.52 6.3073e-06 1.727e-08 d yr n .2179287593494261 8.3208e-10 deg/d Q 3.320404465098686 8.4519e-09 au   Orbit Determination Parameters    # obs. used (total)      4040      data-arc span      52600 days (144.01 yr)      first obs. used      1877-03-11      last obs. used      2021-03-16      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .46215      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 10:21:24   Additional Information  Earth MOID = 1.13222 au   Jupiter MOID = 1.92988 au   T_jup = 3.317  [ 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 8.46   n/a E2020-QM5 IRAS observations used: 6 diameter diameter 109.79 km 3.0 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 6 rotation period rot_per 34.445 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Pilcher, F. (2011) Minor Planet Bull. 38, 76-78.] [Pilcher, F. (2012) Minor Planet Bull. 39, 134-135.] geometric albedo albedo 0.0676   0.004 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 6 B-V BV 0.721   0.028 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=5.40, mean=9.53, max.=13.67) deg. U-B UB 0.299   0.025 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=5.40, mean=9.53, max.=13.67) deg. Tholen spectral type spec_T P   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices; used ground-based radiometric albedo SMASSII spectral type spec_B Xc   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002) 140 Siwa (A874 TB)          Discovered 1874-Oct-13 by Palisa, J. at Pola Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  A874 TB = 1948 AL  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-18 21:16 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin