******************************************************************************* JPL/HORIZONS Lemmon (C/2021 T4) 2025-Dec-12 21:13:12 Rec #:90004719 (+COV) Soln.date: 2025-Apr-14_09:29:19 # obs: 1259 (2021-2025) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2460048.5 ! 2023-Apr-14.0000000 (TDB) RMSW= n.a. EC= .9999181935018592 QR= 1.483297977245064 TP= 2460157.0270268307 OM= 257.8823122014759 W= 329.8139299963154 IN= 160.777408841796 A= 18131.78672789139 MA= 359.9999561892108 ADIST= 36262.09015780554 PER= 2441569.5803825 N= 4.04E-7 ANGMOM= .029627961 DAN= 1.59118 DDN= 21.86478 L= 286.6604281 B= -9.528872099999999 MOID= .49752799 TP= 2023-Jul-31.5270268307 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 12.4 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= 9.208681583405E-9 A2= -3.958460986614E-9 A3= 0. Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 COMET comments 1: soln ref.= JPL#98, data arc: 2021-08-07 to 2025-03-24 2: k1=4.5; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 21:13:12 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Lemmon (C/2021 T4) {source: JPL#98} Center body name: Solar System Barycenter (0) {source: DE441} Center-site name: BODY CENTER ******************************************************************************* Start time : A.D. 1800-Jan-01 00:00:00.0000 TDB Stop time : A.D. 2200-Jan-01 00:00:00.0000 TDB Step-size : 400 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= 2460048.5 ! 2023-Apr-14.0000000 (TDB) RMSW= n.a. EC= .9999181935018592 QR= 1.483297977245064 TP= 2460157.0270268307 OM= 257.8823122014759 W= 329.8139299963154 IN= 160.777408841796 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X= 1.968197185783401E+00 Y= 7.785134019091711E-02 Z=-7.145498016163827E-01 VX=-1.020770758015099E-02 VY=-1.303107474548769E-02 VZ=-2.902693214611334E-03 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 12.4 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= 9.208681583405E-9 A2= -3.958460986614E-9 A3= 0. 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 ******************************************************************************* $$SOE 2378496.500000000 = A.D. 1800-Jan-01 00:00:00.0000 TDB EC= 9.999384670761199E-01 QR= 1.475497163326452E+00 IN= 1.607130285529157E+02 OM= 2.578062508391724E+02 W = 3.298444270460724E+02 Tp= 2460156.094198526349 N = 2.656128092065637E-07 MA= 3.599783101657863E+02 TA= 1.897002456657865E+02 A = 2.397898669965233E+04 AD= 4.795649790214132E+04 PR= 1.355356321388975E+09 2524593.500000000 = A.D. 2200-Jan-01 00:00:00.0000 TDB EC= 9.986026957210299E-01 QR= 1.486693691976917E+00 IN= 1.607798938364559E+02 OM= 2.578329717139478E+02 W = 3.296954357250486E+02 Tp= 2460155.839749924373 N = 2.841839135476634E-05 MA= 1.831214646972102E+00 TA= 1.697843287258094E+02 A = 1.063972761232455E+03 AD= 2.126458828772934E+03 PR= 1.266785285295963E+07 $$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 CENTER = '@0' COMMAND = '2021 T4' OUT_UNITS = 'AU-D' START_TIME = '1800-01-01' STEP_SIZE = '400 years' STOP_TIME = '2200-01-01' TABLE_TYPE = 'ELEMENTS'