+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   2145 Blaauw (1976 UF) Classification: Outer Main-belt Asteroid          SPK-ID: 2002145 [ 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 37 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .0999553516474217 4.4697e-08   a 3.216874743652712 2.0354e-08 au q 2.895330897445195 1.4045e-07 au i 15.01456138627091 3.8551e-06 deg node 264.2963075759108 1.9082e-05 deg peri 278.5070026596896 2.8839e-05 deg M 125.218491472051 2.342e-05 deg tp 2458267.480344684187 (2018-May-28.98034468) 0.00013524 TDB period 2107.412993172761 5.77 2.0001e-05 5.476e-08 d yr n .1708255577650261 1.6213e-09 deg/d Q 3.538418589860228 2.2388e-08 au   Orbit Determination Parameters    # obs. used (total)      2548      data-arc span      16094 days (44.06 yr)      first obs. used      1976-10-24      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .3621      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 02:04:34   Additional Information  Earth MOID = 1.94539 au   Jupiter MOID = 1.7251 au   T_jup = 3.129  [ 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 11.0   n/a MPO452191   diameter diameter 40.549 km 0.848 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   rotation period rot_per 12.141 h n/a LCDB (Rev. 2020-October); 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: [Moravec, P.; Cochren, J.; Gerhardt, M.; Harris, A.; et al. (2012) Minor Planet Bull. 39, 213-216.] geometric albedo albedo 0.051   0.011 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   2145 Blaauw (1976 UF)          Discovered 1976-Oct-24 by West, R. M. at La Silla Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1976 UF = 1929 XS = 1963 RK = 1980 TW  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-23 18:12 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin