+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   955 Alstede (A921 PD) Classification: Main-belt Asteroid          SPK-ID: 2000955 [ 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 44 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2875916760824783 1.4014e-08   a 2.595622483881076 6.2571e-09 au q 1.849143063264352 3.7282e-08 au i 10.68932732304344 1.2166e-06 deg node 351.4439367316368 3.4955e-06 deg peri 282.6529325527251 6.0368e-06 deg M 311.0034928788721 6.2031e-06 deg tp 2459408.385088305198 (2021-Jul-12.88508830) 2.6707e-05 TDB period 1527.427896132617 4.18 5.5231e-06 1.512e-08 d yr n .2356903398919875 8.5225e-10 deg/d Q 3.342101904497801 8.0566e-09 au   Orbit Determination Parameters    # obs. used (total)      3095      data-arc span      36372 days (99.58 yr)      first obs. used      1921-08-06      last obs. used      2021-03-06      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .42592      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 11:41:04   Additional Information  Earth MOID = .867093 au   Jupiter MOID = 1.95929 au   T_jup = 3.334  [ 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 10.8   n/a MPO384754   diameter diameter 17.33 km 1.0 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 12 rotation period rot_per 5.19 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [LeCrone, C.; Duncan, A.; Ditteon, R. (2004) Minor Planet Bull. 31, 78-80.] [Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.] [Durech, J.; Hanus, J.; Oszkiewsicz, D.; Vanco, R. (2016) Astron. Astrophys. 587, A48.] [Durech, J.; Hanus, J.; Broz, M.; Lehky, M.; et al. (2017) Icarus 304, 101-109.] geometric albedo albedo 0.2135   0.028 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 12 955 Alstede (A921 PD)          Discovered 1921-Aug-05 by Reinmuth, K. at Heidelberg Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  A921 PD = 1946 OF = 1955 TY = 1966 DF  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-19 04:38 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin