+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   261P/Larson Classification: Jupiter-family Comet          SPK-ID: 1001652 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2456691.5 (2014-Feb-03.0) TDB Reference: JPL 48 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .3918044347909574 7.5432e-07   a 3.591629764697532 2.658e-07 au q 2.184413294761836 2.6126e-06 au i 6.336230938813235 1.2242e-05 deg node 298.4259584681838 0.0001101 deg peri 58.97380853896804 0.0002556 deg M 71.08670070221258 6.7232e-05 deg tp 2456200.567676781030 (2012-Sep-30.06767678) 0.00047928 TDB period 2486.19832701461 6.81 0.00027599 7.556e-07 d yr n .1447993895291059 1.6074e-08 deg/d Q 4.998846234633228 3.6994e-07 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 4.005917038976903E-9 7.892E-10 A2 [EST] 8.846469482309593E-10 1.318E-11   Orbit Determination Parameters    # obs. used (total)      1014      data-arc span      5337 days (14.61 yr)      first obs. used      2005-07-03      last obs. used      2020-02-12      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .76616      source      ORB      producer      Otto Matic      solution date      2021-Apr-15 23:28:08   Additional Information  Earth MOID = 1.18642 au   Jupiter MOID = .720208 au   T_jup = 2.968  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes comet total magnitude M1 7.5   0.8 48 2 parameter fit from 548 observations, autocmod 2.9c comet total magnitude slope K1 27.   n/a 48 autocmod 2.9c comet nuclear magnitude M2 15.7   0.7 48 from 399 observations, autocmod 2.9c comet nuclear magnitude slope K2 5.   n/a 48 autocmod 2.9c comet nuclear phase coefficient PC 0.03   n/a 48 autocmod 2.9c [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   2012.7   261P/2012 K4         2005.9   261P/2005 N3        [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] 2021-Apr-23 15:21 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin