******************************************************************************* JPL/HORIZONS 26P/Grigg-Skjellerup 2024-Apr-25 23:00:22 Rec #:90000375 (+COV) Soln.date: 2024-Apr-16_10:15:55 # obs: 453 (2007-2024) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2455634.5 ! 2011-Mar-14.0000000 (TDB) RMSW= n.a. EC= .6350668682193706 QR= 1.107963151753838 TP= 2456481.9798256983 OM= 211.6466323027251 W= 1.607119060862649 IN= 22.44388602182615 A= 3.036071694416234 MA= 202.1060795683673 ADIST= 4.964180237078629 PER= 5.2902504957166 N= .186309946 ANGMOM= .023153245 DAN= 1.10813 DDN= 4.96078 L= 213.1320751 B= .6134946999999999 MOID= .103172 TP= 2013-Jul-08.4798256983 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= 1.3 M1= 16.5 M2= n.a. k1= 5.5 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= -5.197498830967E-12 A3= 0. Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 COMET comments 1: soln ref.= JPL#K234/16, data arc: 2007-12-19 to 2024-03-10 2: k1=5.5; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Thu Apr 25 23:00:22 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: 26P/Grigg-Skjellerup {source: JPL#K234/16} Center body name: Earth (399) {source: DE441} Center-site name: GEOCENTRIC ******************************************************************************* Start time : A.D. 2023-Dec-25 00:00:00.0000 UT Stop time : A.D. 2023-Dec-26 00:00:00.0000 UT Step-size : 60 minutes ******************************************************************************* Target pole/equ : undefined Target radii : 1.3 km 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.240425.p240719 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-APR-25. PREDICTS-> 2024-JUL-18 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= 2455634.5 ! 2011-Mar-14.0000000 (TDB) RMSW= n.a. EC= .6350668682193706 QR= 1.107963151753838 TP= 2456481.9798256983 OM= 211.6466323027251 W= 1.607119060862649 IN= 22.44388602182615 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X= 3.806007448511422E+00 Y= 2.940679418650344E+00 Z= 9.891249829583997E-01 VX=-3.530523989460750E-03 VY= 3.217220623610765E-03 VZ=-4.949939781401161E-04 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= 1.3 M1= 16.5 M2= n.a. k1= 5.5 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= -5.197498830967E-12 A3= 0. Standard model: ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808 ******************************************************************************* Date__(UT)__HR:MN r rdot ************************************************** $$SOE 2023-Dec-25 00:00 1.083909370857 -0.0993303 2023-Dec-25 01:00 1.083907120588 -0.0876894 2023-Dec-25 02:00 1.083905150452 -0.0760485 2023-Dec-25 03:00 1.083903460451 -0.0644074 2023-Dec-25 04:00 1.083902050587 -0.0527663 2023-Dec-25 05:00 1.083900920861 -0.0411251 2023-Dec-25 06:00 1.083900071276 -0.0294839 2023-Dec-25 07:00 1.083899501831 -0.0178426 2023-Dec-25 08:00 1.083899212528 -0.0062013 2023-Dec-25 09:00 1.083899203367 0.0054400 2023-Dec-25 10:00 1.083899474348 0.0170812 2023-Dec-25 11:00 1.083900025470 0.0287225 2023-Dec-25 12:00 1.083900856733 0.0403637 2023-Dec-25 13:00 1.083901968136 0.0520049 2023-Dec-25 14:00 1.083903359677 0.0636460 2023-Dec-25 15:00 1.083905031355 0.0752871 2023-Dec-25 16:00 1.083906983169 0.0869280 2023-Dec-25 17:00 1.083909215114 0.0985689 2023-Dec-25 18:00 1.083911727190 0.1102096 2023-Dec-25 19:00 1.083914519392 0.1218502 2023-Dec-25 20:00 1.083917591718 0.1334907 2023-Dec-25 21:00 1.083920944164 0.1451310 2023-Dec-25 22:00 1.083924576726 0.1567711 2023-Dec-25 23:00 1.083928489399 0.1684111 2023-Dec-26 00:00 1.083932682179 0.1800508 $$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. '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 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 = '90000375' START_TIME = '2023-Dec-25' STOP_TIME = '2023-Dec-26' STEP_SIZE = '1 hour' QUANTITIES = '19'