+ 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 | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 31 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1620480043527134 3.616e-08   a 2.39311992188517 6.7279e-09 au q 2.005319614366956 8.875e-08 au i 5.404221776057377 3.5533e-06 deg node 296.4943098088619 3.6239e-05 deg peri 49.03517562202781 3.7652e-05 deg M 245.257825332739 1.1823e-05 deg tp 2459431.488513749799 (2021-Aug-04.98851375) 4.5247e-05 TDB period 1352.213041105954 3.70 5.7024e-06 1.561e-08 d yr n .2662302381772339 1.1227e-09 deg/d Q 2.780920229403382 7.8182e-09 au   Orbit Determination Parameters    # obs. used (total)      2766      data-arc span      32140 days (87.99 yr)      first obs. used      1932-08-08      last obs. used      2020-08-06      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .41499      source      ORB      producer      Otto Matic      solution date      2020-Aug-24 22:31:05   Additional Information  Earth MOID = 1.00248 au   Jupiter MOID = 2.62668 au   T_jup = 3.507  [ 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 12.9   n/a MPO332826   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. 2019-August); 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.] 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 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Oct-01 16:29 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin