+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   174 Phaedra (A877 RA) Classification: Main-belt Asteroid          SPK-ID: 2000174 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 51 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1411614255845109 3.8019e-08   a 2.861916562220357 1.0438e-08 au q 2.457924340393409 1.0881e-07 au i 12.12324734321833 4.4142e-06 deg node 327.657034374718 1.9744e-05 deg peri 289.5067493944895 2.5506e-05 deg M 255.2908071526183 1.8181e-05 deg tp 2459514.858818296046 (2021-Oct-27.35881830) 9.0238e-05 TDB period 1768.413732846445 4.84 9.6742e-06 2.649e-08 d yr n .2035722711904882 1.1137e-09 deg/d Q 3.265908784047305 1.1911e-08 au   Orbit Determination Parameters    # obs. used (total)      2824      data-arc span      52102 days (142.65 yr)      first obs. used      1877-09-03      last obs. used      2020-04-28      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .45167      source      ORB      producer      Otto Matic      solution date      2020-May-20 01:00:13   Additional Information  Earth MOID = 1.47496 au   Jupiter MOID = 2.00501 au   T_jup = 3.254  [ 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 8.3   n/a MPO502154 IRAS observations used: 19 diameter diameter 64.849 km 0.392 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 5.744 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List: [Magnusson, P.; Lagerkvist, C.-I. (1991) Astron. Astrophys. Suppl. Ser. 87, 269-275.] [Sada, P.V.; Cooney, W. (2001) Minor Planet Bull. 28, 39-40.] [Wang, X.-B.; Shi, Y. (2002) Earth, Moon, and Planets 91, 181-186; Wang, X.-B. (2002) Proc. ACM 2002, ESA SP 500, 501-503.] [Ivarsen, K.; Willis, S.; Ingleby, L.; Matthews, D.; Simet, M. (2004) Minor Planet Bull. 31, 29-33.] [Durech, J. (2006) IAU 2006, poster paper.] [Ruthroff, J.C. (2009) Minor Planet Bull. 36, 121-122.] [Hanus, J.; Durech, J.; Broz, M.; Warner, B.D.; et al. (2011) Astron. Astrophys. 530, A134.] [U. Iowa Physics web site (2011) http://phobos.physics.uiowa.edu/research/asteroids/] [Marciniak, A.; Michalowski, T.; Polinska, M.; Bartczak, P.; et al. (2011) Astron. Astrophys. 529, A107.] [Behrend, R. (2018) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] geometric albedo albedo 0.169   0.017 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   B-V BV 0.858   0.018 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=10.52, mean=14.11, max.=17.69) deg. U-B UB 0.484   0.050 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=10.52, mean=14.11, max.=17.69) deg. Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices SMASSII spectral type spec_B S   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) 174 Phaedra (A877 RA)          Discovered 1877-Sep-02 by Watson, J. C. at Ann Arbor Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Sep-24 03:22 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin