******************************************************************************* JPL/HORIZONS 26P/Grigg-Skjellerup 2024-Apr-27 21:30:54 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 Sat Apr 27 21:30:54 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.240426.p240720 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-APR-26. PREDICTS-> 2024-JUL-19 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 delta deldot VmagSn VmagOb S-O-T /r ********************************************************************************************************************** $$SOE 2023-Dec-25 00:00 1.083909370857 -0.0993303 1.79631310409331 0.0316331 36.6439538 57.5331407 31.2991 /L 2023-Dec-25 01:00 1.083907120588 -0.0876894 1.79631398053291 0.0412108 36.6440003 57.5303273 31.2988 /L 2023-Dec-25 02:00 1.083905150452 -0.0760485 1.79631508738314 0.0507835 36.6440410 57.5275094 31.2986 /L 2023-Dec-25 03:00 1.083903460451 -0.0644074 1.79631642452714 0.0603515 36.6440760 57.5246869 31.2983 /L 2023-Dec-25 04:00 1.083902050587 -0.0527663 1.79631799184769 0.0699145 36.6441052 57.5218598 31.2980 /L 2023-Dec-25 05:00 1.083900920861 -0.0411251 1.79631978922721 0.0794727 36.6441286 57.5190281 31.2978 /L 2023-Dec-25 06:00 1.083900071276 -0.0294839 1.79632181654780 0.0890259 36.6441462 57.5161919 31.2975 /L 2023-Dec-25 07:00 1.083899501831 -0.0178426 1.79632407369121 0.0985742 36.6441581 57.5133509 31.2973 /L 2023-Dec-25 08:00 1.083899212528 -0.0062013 1.79632656053883 0.1081176 36.6441642 57.5105054 31.2970 /L 2023-Dec-25 09:00 1.083899203367 0.0054400 1.79632927697172 0.1176561 36.6441645 57.5076553 31.2968 /L 2023-Dec-25 10:00 1.083899474348 0.0170812 1.79633222287058 0.1271895 36.6441590 57.5048005 31.2965 /L 2023-Dec-25 11:00 1.083900025470 0.0287225 1.79633539811580 0.1367180 36.6441478 57.5019410 31.2963 /L 2023-Dec-25 12:00 1.083900856733 0.0403637 1.79633880258742 0.1462416 36.6441308 57.4990769 31.2961 /L 2023-Dec-25 13:00 1.083901968136 0.0520049 1.79634243616512 0.1557601 36.6441080 57.4962082 31.2959 /L 2023-Dec-25 14:00 1.083903359677 0.0636460 1.79634629872828 0.1652735 36.6440795 57.4933348 31.2957 /L 2023-Dec-25 15:00 1.083905031355 0.0752871 1.79635039015591 0.1747820 36.6440452 57.4904567 31.2955 /L 2023-Dec-25 16:00 1.083906983169 0.0869280 1.79635471032676 0.1842854 36.6440051 57.4875739 31.2953 /L 2023-Dec-25 17:00 1.083909215114 0.0985689 1.79635925911912 0.1937837 36.6439592 57.4846864 31.2951 /L 2023-Dec-25 18:00 1.083911727190 0.1102096 1.79636403641108 0.2032770 36.6439076 57.4817943 31.2949 /L 2023-Dec-25 19:00 1.083914519392 0.1218502 1.79636904208033 0.2127652 36.6438502 57.4788974 31.2947 /L 2023-Dec-25 20:00 1.083917591718 0.1334907 1.79637427600426 0.2222483 36.6437870 57.4759958 31.2945 /L 2023-Dec-25 21:00 1.083920944164 0.1451310 1.79637973805993 0.2317262 36.6437180 57.4730895 31.2944 /L 2023-Dec-25 22:00 1.083924576726 0.1567711 1.79638542812407 0.2411990 36.6436433 57.4701785 31.2942 /L 2023-Dec-25 23:00 1.083928489399 0.1684111 1.79639134607311 0.2506667 36.6435628 57.4672627 31.2940 /L 2023-Dec-26 00:00 1.083932682179 0.1800508 1.79639749178311 0.2601293 36.6434765 57.4643421 31.2939 /L $$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 '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 'VmagSn VmagOb' = Magnitude of target centers' velocity with respect to the Sun ("VmagSn") and the observer ("VmagOb") at the time light left the target center to be observed (print time minus down-leg light-time). These are absolute values of the velocity vectors (total speeds) and do NOT indicate direction of motion. Units: 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 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 = '19,20,22,23'