+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   1273 Helma (1932 PF) Classification: Main-belt Asteroid          SPK-ID: 2001273 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 36 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1621012470108277 1.4626e-08   a 2.394231091805522 6.1383e-09 au q 2.006123246191751 3.55e-08 au i 5.402947969836327 1.0619e-06 deg node 296.49240195 8.9242e-06 deg peri 48.81497227544664 1.0412e-05 deg M 350.8506269410392 7.9593e-06 deg tp 2459430.890331453102 (2021-Aug-04.39033145) 2.9983e-05 TDB period 1353.154936773651 3.70 5.2038e-06 1.425e-08 d yr n .2660449222897961 1.0231e-09 deg/d Q 2.782338937419292 7.1333e-09 au   Orbit Determination Parameters    # obs. used (total)      2884      data-arc span      32465 days (88.88 yr)      first obs. used      1932-08-08      last obs. used      2021-06-27      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .41022      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 12:11:03   Additional Information  Earth MOID = 1.00239 au   Jupiter MOID = 2.62414 au   T_jup = 3.506  [ 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 12.92   n/a E2021B10   diameter diameter 6.278 km 0.287 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   rotation period rot_per 6.0851 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Higgins, D.; Goncalves, R.M.D. (2007) Minor Planet Bull. 34, 16-18.] [Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.] [Durech, J.; Hanus, J.; Ali-Lagoa, V. (2018) Astron. Astrophys. 617, A57.] [Erasmus, N.; Navarro-Meza, S.; McNeill, A.; Trilling, D.E.; et al. (2020) Ap. J. Suppl. Ser. 247, A13.] geometric albedo albedo 0.340   0.047 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   1273 Helma (1932 PF)          Discovered 1932-Aug-08 by Reinmuth, K. at Heidelberg Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jul-29 10:37 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin