******************************************************************************* JPL/HORIZONS Leonard (C/2021 A1) 2025-Jul-14 23:25:12 Rec #:90004658 (+COV) Soln.date: 2025-Jan-02_20:12:26 # obs: 2422 (2020-2022) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2459406.5 ! 2021-Jul-11.0000000 (TDB) RMSW= n.a. EC= 1.00010048049546 QR= .6152301948171482 TP= 2459582.7926796316 OM= 255.8891037387722 W= 225.0877130387106 IN= 132.6858126158049 A= -6122.881779196637 MA= -.000362664078866112ADIST= 9.999999E99 PER= 9.999999E99 N= 2.057E-6 ANGMOM= .0190821 DAN= 4.18679 DDN= .7212499999999999 L= 41.6711816 B= -31.370959 MOID= .231957 TP= 2022-Jan-03.2926796316 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 12.5 M2= n.a. k1= 4.5 k2= n.a. PHCOF= n.a. Comet non-gravitational force model (AMRAT=m^2/kg;A1-A3=au/d^2;DT=days;R0=au): AMRAT= 0. DT= 0. A1= 5.811942577362E-8 A2= -2.033043861389E-8 A3= 1.102413654327E-8 Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 COMET comments 1: soln ref.= JPL#32, data arc: 2020-04-11 to 2022-01-22 2: k1=4.5; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Mon Jul 14 23:25:13 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Leonard (C/2021 A1) {source: JPL#32} Center body name: Solar System Barycenter (0) {source: DE441} Center-site name: BODY CENTER ******************************************************************************* Start time : A.D. 1950-Jan-01 00:00:00.0000 TDB Stop time : A.D. 2100-Jan-01 00:00:00.0000 TDB Step-size : 150 calendar years ******************************************************************************* Center geodetic : 0.0, 0.0, 0.0 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)} Center radii : (undefined) Keplerian GM : 2.9630927493968080E-04 au^3/d^2 Small perturbers: Yes {source: SB441-N16} Output units : AU-D, deg, Julian Day Number (Tp) Calendar mode : Mixed Julian/Gregorian Output type : GEOMETRIC osculating elements Output format : 10 Reference frame : Ecliptic of J2000.0 ******************************************************************************* Initial IAU76/J2000 heliocentric ecliptic osculating elements (au, days, deg.): EPOCH= 2459406.5 ! 2021-Jul-11.0000000 (TDB) RMSW= n.a. EC= 1.00010048049546 QR= .6152301948171482 TP= 2459582.7926796316 OM= 255.8891037387722 W= 225.0877130387106 IN= 132.6858126158049 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X=-1.807972933212298E+00 Y= 1.365331540259884E-02 Z= 2.351056893358045E+00 VX= 9.897579202685157E-03 VY= 5.738055188980243E-03 VZ=-8.288879836330219E-03 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 12.5 M2= n.a. k1= 4.5 k2= n.a. PHCOF= n.a. Comet non-gravitational force model (AMRAT=m^2/kg;A1-A3=au/d^2;DT=days;R0=au): AMRAT= 0. DT= 0. A1= 5.811942577362E-8 A2= -2.033043861389E-8 A3= 1.102413654327E-8 Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 ******************************************************************************* JDTDB EC QR IN OM W Tp N MA TA A AD PR ******************************************************************************* $$SOE 2433282.500000000 = A.D. 1950-Jan-01 00:00:00.0000 TDB EC= 9.996964880742506E-01 QR= 6.156416444661131E-01 IN= 1.327435348419870E+02 OM= 2.560766971330320E+02 W = 2.253053766546996E+02 Tp= 2459583.247022041120 N = 1.079610031701221E-05 MA= 3.597160544967377E+02 TA= 1.890648502210806E+02 A = 2.028393589299522E+03 AD= 4.056171536954578E+03 PR= 3.334537373950864E+07 2488069.500000000 = A.D. 2100-Jan-01 00:00:00.0000 TDB EC= 9.996591660482022E-01 QR= 6.111933334640409E-01 IN= 1.325413420315211E+02 OM= 2.557966898287534E+02 W = 2.249220908180458E+02 Tp= 2459582.877094889525 N = 1.298798018787725E-05 MA= 3.699836939111172E-01 TA= 1.712237245170928E+02 A = 1.793229020294527E+03 AD= 3.585846847255589E+03 PR= 2.771793572152333E+07 $$EOE ******************************************************************************* TIME Barycentric Dynamical Time ("TDB" or T_eph) output was requested. This continuous coordinate time is equivalent to the relativistic proper time of a clock at rest in a reference frame co-moving with the solar system barycenter but outside the system's gravity well. It is the independent variable in the solar system relativistic equations of motion. TDB runs at a uniform rate of one SI second per second and is independent of irregularities in Earth's rotation. CALENDAR SYSTEM Mixed calendar mode was active such that calendar dates after AD 1582-Oct-15 (if any) are in the modern Gregorian system. Dates prior to 1582-Oct-5 (if any) are in the Julian calendar system, which is automatically extended for dates prior to its adoption on 45-Jan-1 BC. The Julian calendar is useful for matching historical dates. The Gregorian calendar more accurately corresponds to the Earth's orbital motion and seasons. A "Gregorian-only" calendar mode is available if such physical events are the primary interest. REFERENCE FRAME AND COORDINATES Ecliptic at the standard reference epoch Reference epoch: J2000.0 X-Y plane: adopted Earth orbital plane at the reference epoch Note: IAU76 obliquity of 84381.448 arcseconds wrt ICRF X-Y plane X-axis : ICRF Z-axis : perpendicular to the X-Y plane in the directional (+ or -) sense of Earth's north pole at the reference epoch. Symbol meaning [1 au= 149597870.700 km, 1 day= 86400.0 s]: JDTDB Julian Day Number, Barycentric Dynamical Time EC Eccentricity, e QR Periapsis distance, q (au) IN Inclination w.r.t X-Y plane, i (degrees) OM Longitude of Ascending Node, OMEGA, (degrees) W Argument of Perifocus, w (degrees) Tp Time of periapsis (Julian Day Number) N Mean motion, n (degrees/day) MA Mean anomaly, M (degrees) TA True anomaly, nu (degrees) A Semi-major axis, a (au) AD Apoapsis distance (au) PR Sidereal orbit period (day) ABERRATIONS AND CORRECTIONS Geometric osculating elements have NO corrections or aberrations applied. Computations by ... Solar System Dynamics Group, Horizons On-Line Ephemeris System 4800 Oak Grove Drive, Jet Propulsion Laboratory Pasadena, CA 91109 USA General site: https://ssd.jpl.nasa.gov/ Mailing list: https://ssd.jpl.nasa.gov/email_list.html System news : https://ssd.jpl.nasa.gov/horizons/news.html User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/x API https://ssd-api.jpl.nasa.gov/doc/horizons.html command-line telnet ssd.jpl.nasa.gov 6775 e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/horizons_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ******************************************************************************* !$$SOF COMMAND = '2021 A1' TABLE_TYPE = 'ELEMENTS' START_TIME = '1950-01-01' STOP_TIME = '2100-01-01' STEP_SIZE = '150 years' CENTER = '@0' OUT_UNITS = 'AU-D'