+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1909 Alekhin (1972 RW2) Classification: Main-belt Asteroid          SPK-ID: 2001909 [ 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 40 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2254168656710686 1.3843e-08   a 2.422621952276291 6.5945e-09 au q 1.876522105088244 3.6007e-08 au i 1.795612800557789 1.1097e-06 deg node 227.4383358396279 2.9085e-05 deg peri 5.841001543246527 2.9168e-05 deg M 7.24924067375887 7.9537e-06 deg tp 2459172.765718650863 (2020-Nov-19.26571865) 3.0367e-05 TDB period 1377.294772655444 3.77 5.6236e-06 1.54e-08 d yr n .2613819547909231 1.0672e-09 deg/d Q 2.968721799464337 8.081e-09 au   Orbit Determination Parameters    # obs. used (total)      3345      data-arc span      34413 days (94.22 yr)      first obs. used      1926-04-14      last obs. used      2020-07-02      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .4528      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 13:05:51   Additional Information  Earth MOID = .864207 au   Jupiter MOID = 2.02997 au   T_jup = 3.477  [ 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 12.82   n/a E2021B10   diameter diameter 18.681 km 0.043 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 148.6 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Dymock, R. (2009) Minor Planet Bull. 36, 182-183.] [Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.] geometric albedo albedo 0.060   0.004 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   1909 Alekhin (1972 RW2)          Discovered 1972-Sep-04 by Zhuravleva, L. at Nauchnyj Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1972 RW2 = 1926 GU = 1930 KF = 1930 KM = 1934 NZ = 1934 OC = 1941 FJ = 1960 FD = 1969 UU = 1971 DL  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-18 22:18 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin