******************************************************************************* JPL/HORIZONS Lemmon (C/2021 T4) 2024-May-04 19:58:32 Rec #:90004698 (+COV) Soln.date: 2024-Apr-29_13:12:18 # obs: 1935 (2021-2024) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2459991.5 ! 2023-Feb-16.0000000 (TDB) RMSW= n.a. EC= 1.000079645429152 QR= 1.483334896846756 TP= 2460157.0158690587 OM= 257.872536762289 W= 329.7996912315901 IN= 160.7760778884165 A= -18624.23132926656 MA= -6.4183910942667E-5 ADIST= 9.999999E99 PER= 9.999999E99 N= 3.88E-7 ANGMOM= .029629525 DAN= 1.59133 DDN= 21.86944 L= 286.6642807 B= -9.533621800000001 MOID= .497067 TP= 2023-Jul-31.5158690587 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 11.9 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= 0. A2= 0. A3= 2.365417480469E-9 Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 COMET comments 1: soln ref.= JPL#76, data arc: 2021-08-07 to 2024-04-29 2: k1=4.5; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Sat May 4 19:58:32 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: Lemmon (C/2021 T4) {source: JPL#76} Center body name: Earth (399) {source: DE441} Center-site name: GEOCENTRIC ******************************************************************************* Start time : A.D. 2023-Jul-20 00:00:00.0000 UT Stop time : A.D. 2023-Jul-21 00:00:00.0000 UT Step-size : 60 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 0.0, 0.0, -6378.137 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)} Center pole/equ : ITRF93 {East-longitude positive} Center radii : 6378.137, 6378.137, 6356.752 km {Equator_a, b, pole_c} Target primary : Sun Vis. interferer : MOON (R_eq= 1737.400) km {source: DE441} Rel. light bend : Sun {source: DE441} Rel. lght bnd GM: 1.3271E+11 km^3/s^2 Small-body perts: Yes {source: SB441-N16} Atmos refraction: NO (AIRLESS) RA format : HMS Time format : CAL Calendar mode : Mixed Julian/Gregorian EOP file : eop.240503.p240727 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-MAY-03. PREDICTS-> 2024-JUL-26 Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO ) Table cut-offs 2: Solar elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO ) Table cut-offs 3: RA/DEC angular rate ( 0.0=NO ) ******************************************************************************* Initial IAU76/J2000 heliocentric ecliptic osculating elements (au, days, deg.): EPOCH= 2459991.5 ! 2023-Feb-16.0000000 (TDB) RMSW= n.a. EC= 1.000079645429152 QR= 1.483334896846756 TP= 2460157.0158690587 OM= 257.872536762289 W= 329.7996912315901 IN= 160.7760778884165 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X= 2.461489661255370E+00 Y= 8.083144208599147E-01 Z=-5.215557781662032E-01 VX=-7.327636149623326E-03 VY=-1.250319200706491E-02 VZ=-3.732468272063531E-03 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 11.9 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= 0. A2= 0. A3= 2.365417480469E-9 Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 ************************************************************************************************************************** Date__(UT)__HR:MN r rdot delta deldot S-O-T /r Cnst RNG_3sigma RNGRT_3sig ************************************************************************************************************************** $$SOE 2023-Jul-20 00:00 1.492195463750 -2.6653780 0.54166171524139 -2.3796081 144.8791 /L Tel 101.4087 0.0000113 2023-Jul-20 01:00 1.492131436196 -2.6559063 0.54160667969188 -2.1943171 144.8764 /L Tel 101.3690 0.0000113 2023-Jul-20 02:00 1.492067636636 -2.6464329 0.54155610377518 -2.0089758 144.8725 /L Tel 101.3299 0.0000113 2023-Jul-20 03:00 1.492004065108 -2.6369579 0.54150998864019 -1.8235890 144.8677 /L Tel 101.2915 0.0000113 2023-Jul-20 04:00 1.491940721651 -2.6274813 0.54146833532076 -1.6381616 144.8617 /L Tel 101.2537 0.0000113 2023-Jul-20 05:00 1.491877606304 -2.6180031 0.54143114473551 -1.4526983 144.8548 /L Tel 101.2165 0.0000113 2023-Jul-20 06:00 1.491814719104 -2.6085233 0.54139841768777 -1.2672039 144.8468 /L Tel 101.1800 0.0000113 2023-Jul-20 07:00 1.491752060090 -2.5990419 0.54137015486540 -1.0816832 144.8377 /L Tel 101.1441 0.0000113 2023-Jul-20 08:00 1.491689629300 -2.5895589 0.54134635684077 -0.8961410 144.8276 /L Tel 101.1088 0.0000113 2023-Jul-20 09:00 1.491627426772 -2.5800744 0.54132702407065 -0.7105821 144.8165 /L Tel 101.0742 0.0000113 2023-Jul-20 10:00 1.491565452543 -2.5705882 0.54131215689616 -0.5250114 144.8043 /L Tel 101.0402 0.0000113 2023-Jul-20 11:00 1.491503706652 -2.5611005 0.54130175554270 -0.3394335 144.7911 /L Tel 101.0069 0.0000112 2023-Jul-20 12:00 1.491442189135 -2.5516112 0.54129582011994 -0.1538534 144.7769 /L Tel 100.9742 0.0000112 2023-Jul-20 13:00 1.491380900029 -2.5421204 0.54129435062180 0.0317241 144.7616 /L Tel 100.9422 0.0000112 2023-Jul-20 14:00 1.491319839374 -2.5326280 0.54129734692644 0.2172943 144.7453 /L Tel 100.9108 0.0000112 2023-Jul-20 15:00 1.491259007204 -2.5231340 0.54130480879628 0.4028523 144.7279 /T Tel 100.8801 0.0000112 2023-Jul-20 16:00 1.491198403558 -2.5136385 0.54131673587799 0.5883933 144.7096 /T Tel 100.8501 0.0000112 2023-Jul-20 17:00 1.491138028472 -2.5041415 0.54133312770257 0.7739125 144.6902 /T Tel 100.8207 0.0000112 2023-Jul-20 18:00 1.491077881983 -2.4946429 0.54135398368538 0.9594052 144.6697 /T Tel 100.7920 0.0000112 2023-Jul-20 19:00 1.491017964127 -2.4851428 0.54137930312624 1.1448665 144.6483 /T Tel 100.7639 0.0000112 2023-Jul-20 20:00 1.490958274940 -2.4756412 0.54140908520945 1.3302915 144.6258 /T Tel 100.7365 0.0000112 2023-Jul-20 21:00 1.490898814460 -2.4661380 0.54144332900394 1.5156757 144.6023 /T Tel 100.7098 0.0000112 2023-Jul-20 22:00 1.490839582722 -2.4566334 0.54148203346336 1.7010140 144.5778 /T Tel 100.6838 0.0000112 2023-Jul-20 23:00 1.490780579762 -2.4471272 0.54152519742621 1.8863018 144.5522 /T Tel 100.6585 0.0000112 2023-Jul-21 00:00 1.490721805617 -2.4376196 0.54157281961597 2.0715342 144.5257 /T Tel 100.6338 0.0000112 $$EOE ************************************************************************************************************************** Column meaning: TIME Times PRIOR to 1962 are UT1, a mean-solar time closely related to the prior but now-deprecated GMT. Times AFTER 1962 are in UTC, the current civil or "wall-clock" time-scale. UTC is kept within 0.9 seconds of UT1 using integer leap-seconds for 1972 and later years. Conversion from the internal Barycentric Dynamical Time (TDB) of solar system dynamics to the non-uniform civil UT time-scale requested for output has not been determined for UTC times after the next July or January 1st. Therefore, the last known leap-second is used as a constant over future intervals. Time tags refer to the UT time-scale conversion from TDB on Earth regardless of observer location within the solar system, although clock rates may differ due to the local gravity field and no analog to "UT" may be defined for that location. Any 'b' symbol in the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D. date. 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. NOTE: "n.a." in output means quantity "not available" at the print-time. STATISTICAL UNCERTAINTIES Output includes formal +/- 3 standard-deviation statistical orbit uncertainty quantities. There is a 99.7% (1-D) or 98.9% (2-D) chance the actual value is within given bounds. These statistical calculations assume observational data errors are random. If there are systematic biases (such as timing, reduction or star-catalog errors), results can be optimistic. Because the epoch covariance is mapped using linearized variational partial derivatives, results can also be optimistic for times far from the solution epoch, particularly for objects having close planetary encounters. 'r rdot' = The Sun's apparent range ("r", light-time aberrated) and range-rate ("rdot") relative to the target center, as seen by the observer. A positive "rdot" means the target center was moving away from the Sun, negative means moving toward the Sun. Units: AU and KM/S 'delta deldot' = Apparent range ("delta", light-time aberrated) and range-rate ("delta-dot") of the target center relative to the observer. A positive "deldot" means the target center is moving away from the observer, negative indicates movement toward the observer. Units: AU and KM/S 'S-O-T /r' = Sun-Observer-Target apparent SOLAR ELONGATION ANGLE seen from the observers' location at print-time. The '/r' column provides a code indicating the targets' apparent position relative to the Sun in the observers' sky, as described below: Case A: For an observing location on the surface of a rotating body, that body rotational sense is considered: /T indicates target TRAILS Sun (evening sky: rises and sets AFTER Sun) /L indicates target LEADS Sun (morning sky: rises and sets BEFORE Sun) Case B: For an observing point that does not have a rotational model (such as a spacecraft), the "leading" and "trailing" condition is defined by the observers' heliocentric ORBITAL motion: * If continuing in the observers' current direction of heliocentric motion would encounter the targets' apparent longitude first, followed by the Sun's, the target LEADS the Sun as seen by the observer. * If the Sun's apparent longitude would be encountered first, followed by the targets', the target TRAILS the Sun. Two other codes can be output: /* indicates observer is Sun-centered (undefined) /? Target is aligned with Sun center (no lead or trail) The S-O-T solar elongation angle is numerically the minimum separation angle of the Sun and target in the sky in any direction. It does NOT indicate the amount of separation in the leading or trailing directions, which would be defined along the equator of a spherical coordinate system. Units: DEGREES 'Cnst' = Constellation ID; the 3-letter abbreviation for the name of the constellation containing the target centers' astrometric position, as defined by IAU (1930) boundary delineation. See documentation for list of abbreviations. 'RNG_3sigma RNGRT_3sig' = Range and range rate (radial velocity) formal 3-standard-deviation uncertainties. Units: KM, KM/S 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/hrzn_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ************************************************************************************************************************** !$$SOF COMMAND = '2021 T4' START_TIME = '2023-07-20' STOP_TIME = '2023-07-21' STEP_SIZE = '1 hour' QUANTITIES = '19,20,23,29,39'