+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   19164 (1991 AU1) Classification: Inner Main-belt Asteroid          SPK-ID: 2019164 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 30 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .05462924360979893 2.5694e-08   a 1.855756530425615 4.261e-09 au q 1.754377954844519 4.8172e-08 au i 22.32184972946245 8.4738e-07 deg node 334.6938754759833 3.7696e-06 deg peri 138.8074419507961 1.5078e-05 deg M 327.716099201803 1.4718e-05 deg tp 2459283.306308931211 (2021-Mar-09.80630893) 3.7751e-05 TDB period 923.3788507026057 2.53 3.1802e-06 8.707e-09 d yr n .3898724772893308 1.3428e-09 deg/d Q 1.957135106006711 4.4937e-09 au   Orbit Determination Parameters    # obs. used (total)      2098      data-arc span      24295 days (66.52 yr)      first obs. used      1954-09-04      last obs. used      2021-03-11      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .40061      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 02:47:13   Additional Information  Earth MOID = .784227 au   Jupiter MOID = 3.07077 au   T_jup = 3.907  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 14.22   n/a E2021B10   diameter diameter 3.368 km 0.556 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2015ApJ...814..117N)   rotation period rot_per 32.492 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Warner, B.D. (2006) Minor Planet Bull. 33, 58-62.] geometric albedo albedo 0.316   0.162 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)   19164 (1991 AU1)          Discovered 1991-Jan-12 by Helin, E. F. at Palomar Reference: 20001211/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1991 AU1 = 1954 RA1  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-18 19:18 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin