+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   2640 Hallstrom (1941 FN) Classification: Main-belt Asteroid          SPK-ID: 2002640 [ 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 39 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .09000696725708975 9.8212e-09   a 2.396924073835268 7.0979e-09 au q 2.181184207203847 2.2351e-08 au i 6.65706009824159 8.8151e-07 deg node 4.431352756356718 7.4301e-06 deg peri 192.0536674157258 1.4236e-05 deg M 153.0624024495155 1.3474e-05 deg tp 2458624.203651588409 (2019-May-20.70365159) 5.0258e-05 TDB period 1355.438580004004 3.71 6.0207e-06 1.648e-08 d yr n .2655966897437261 1.1798e-09 deg/d Q 2.612663940466689 7.7368e-09 au   Orbit Determination Parameters    # obs. used (total)      2838      data-arc span      29180 days (79.89 yr)      first obs. used      1941-03-18      last obs. used      2021-02-06      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .42554      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 14:03:35   Additional Information  Earth MOID = 1.17965 au   Jupiter MOID = 2.34578 au   T_jup = 3.514  [ 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 12.97   n/a E2021B10   rotation period rot_per 22.9 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on fragmentary lightcurve(s), may be completely wrong. Published Reference List: [Hasegawa, S.; Miyasaka, S.; Yoshizumi, C.; Sekiguchi, T.; et al. (2012) arXiv:1204.0548.] SMASSII spectral type spec_B V   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002) 2640 Hallstrom (1941 FN)          Discovered 1941-Mar-18 by Oterma, L. at Turku Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  1941 FN = 1967 ET = 1976 SG5 = 1978 EM6  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-23 09:49 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin