+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1578 Kirkwood (1951 AT) Classification: Outer Main-belt Asteroid          SPK-ID: 2001578 [ 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 38 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2400223491300108 3.0948e-08   a 3.923675434039667 2.1777e-08 au q 2.981905639137751 1.2758e-07 au i .8080618967120092 3.5573e-06 deg node 73.98621132730095 0.00030691 deg peri 1.733906164999759 0.00030702 deg M 322.2244058740642 8.6718e-06 deg tp 2459298.383770788256 (2021-Mar-24.88377079) 6.9424e-05 TDB period 2838.821200965446 7.77 2.3634e-05 6.471e-08 d yr n .1268131997455735 1.0558e-09 deg/d Q 4.865445228941582 2.7004e-08 au   Orbit Determination Parameters    # obs. used (total)      2955      data-arc span      28006 days (76.68 yr)      first obs. used      1944-02-21      last obs. used      2020-10-25      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .47155      source      ORB      producer      Otto Matic      solution date      2020-Nov-13 04:17:34   Additional Information  Earth MOID = 1.99713 au   Jupiter MOID = .431467 au   T_jup = 3.012  [ 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 10.2   n/a MPO502168 IRAS observations used: 16 diameter diameter 47.077 km 0.839 urn:nasa:pds:neowise_diameters_albedos::2.0[hildas] (http://adsabs.harvard.edu/abs/2012ApJ...744..197G)   rotation period rot_per 12.518 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Klinglesmith III, D.A.; Hanowell, J.; Risley, E.; Turk, J.; et al. (2013) Minor Planet Bull. 40, 65-67.] geometric albedo albedo 0.063   0.010 urn:nasa:pds:neowise_diameters_albedos::2.0[hildas] (http://adsabs.harvard.edu/abs/2012ApJ...744..197G)   B-V BV 0.788   0.040 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=4.91, mean=5.04, max.=5.17) deg. U-B UB 0.276   0.054 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=4.91, mean=5.04, max.=5.17) deg. Tholen spectral type spec_T D   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo 1578 Kirkwood (1951 AT)          Discovered 1951-Jan-10 by Goethe Link Observatory at Brooklyn Discovered by the Indiana Asteroid Program, Goethe Link Observatory, University of Indiana. This program was conceived and directed by F. K. Edmondson; the plates were blinked and measured astrometrically by B. Potter and, following her retirement, by D. Owings; and the photometry was performed under the direction of T. Gehrels. During the years 1947-1967, in which the plates were exposed, a large number of people participated in various aspects of the program. Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1951 AT = 1944 DF = 1949 TF = 1952 FK  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Nov-30 22:43 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin