******************************************************************************* JPL/HORIZONS SWAN (C/2025 R2) 2025-Dec-12 21:10:35 Rec #:90004928 (+COV) Soln.date: 2025-Dec-12_11:12:32 # obs: 1957 (121 days) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2460981.5 ! 2025-Nov-02.0000000 (TDB) RMSW= n.a. EC= .9940639778783722 QR= .5040873795531586 TP= 2460931.3431196683 OM= 335.3308731732378 W= 308.3519333400561 IN= 4.472875772221829 A= 84.92006418179004 MA= .06317119895197218 ADIST= 169.3360409840269 PER= 782.57086088146 N= .001259472 ANGMOM= .017246616 DAN= .62171 DDN= 2.62317 L= 283.767878 B= -3.5063194 MOID= .0478818 TP= 2025-Sep-12.8431196683 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 14. M2= n.a. k1= 11.75 k2= n.a. PHCOF= n.a. COMET comments 1: soln ref.= JPL#12, data arc: 2025-08-13 to 2025-12-12 2: k1=11.75; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 21:10:35 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: SWAN (C/2025 R2) {source: JPL#12} Center body name: Earth (399) {source: DE441} Center-site name: GEOCENTRIC ******************************************************************************* Start time : A.D. 2025-Oct-19 12:00:00.0000 UT Stop time : A.D. 2025-Oct-20 00:00:00.0000 UT Step-size : 30 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.251212.p260310 EOP coverage : DATA-BASED 1962-JAN-20 TO 2025-DEC-12. PREDICTS-> 2026-MAR-09 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= 2460981.5 ! 2025-Nov-02.0000000 (TDB) RMSW= n.a. EC= .9940639778783722 QR= .5040873795531586 TP= 2460931.3431196683 OM= 335.3308731732378 W= 308.3519333400561 IN= 4.472875772221829 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X= 1.097694327650680E+00 Y= 3.927923144571505E-01 Z= 2.448263320001283E-01 VX= 9.915573067472452E-03 VY= 1.747648878864292E-02 VZ= 9.463846050693878E-03 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 14. M2= n.a. k1= 11.75 k2= n.a. PHCOF= n.a. *************************************************************************************************** Date__(UT)__HR:MN r rdot delta deldot S-O-T /r Cnst *************************************************************************************************** $$SOE 2025-Oct-19 12:00 0.961874051858 29.5013195 0.26148688749894 -1.8036767 74.9551 /T Sct 2025-Oct-19 12:30 0.962229024538 29.5018363 0.26146556065605 -1.7409103 75.0341 /T Sct 2025-Oct-19 13:00 0.962584003333 29.5023483 0.26144498917787 -1.6781334 75.1132 /T Sct 2025-Oct-19 13:30 0.962938988186 29.5028555 0.26142517318819 -1.6153464 75.1922 /T Sct 2025-Oct-19 14:00 0.963293979038 29.5033579 0.26140611280487 -1.5525498 75.2713 /T Sct 2025-Oct-19 14:30 0.963648975831 29.5038555 0.26138780813974 -1.4897442 75.3504 /T Sct 2025-Oct-19 15:00 0.964003978509 29.5043483 0.26137025929868 -1.4269300 75.4295 /T Sct 2025-Oct-19 15:30 0.964358987013 29.5048363 0.26135346638156 -1.3641077 75.5086 /T Sct 2025-Oct-19 16:00 0.964714001287 29.5053196 0.26133742948225 -1.3012778 75.5877 /T Sct 2025-Oct-19 16:30 0.965069021272 29.5057981 0.26132214868862 -1.2384409 75.6668 /T Sct 2025-Oct-19 17:00 0.965424046912 29.5062719 0.26130762408253 -1.1755974 75.7459 /T Sct 2025-Oct-19 17:30 0.965779078150 29.5067410 0.26129385573981 -1.1127478 75.8251 /T Sct 2025-Oct-19 18:00 0.966134114929 29.5072053 0.26128084373029 -1.0498927 75.9042 /T Sct 2025-Oct-19 18:30 0.966489157192 29.5076649 0.26126858811776 -0.9870324 75.9834 /T Sct 2025-Oct-19 19:00 0.966844204882 29.5081198 0.26125708896000 -0.9241676 76.0625 /T Sct 2025-Oct-19 19:30 0.967199257943 29.5085700 0.26124634630874 -0.8612988 76.1417 /T Sct 2025-Oct-19 20:00 0.967554316319 29.5090156 0.26123636020968 -0.7984263 76.2209 /T Sct 2025-Oct-19 20:30 0.967909379953 29.5094564 0.26122713070249 -0.7355508 76.3001 /T Sct 2025-Oct-19 21:00 0.968264448789 29.5098927 0.26121865782078 -0.6726728 76.3792 /T Sct 2025-Oct-19 21:30 0.968619522771 29.5103242 0.26121094159214 -0.6097926 76.4584 /T Sct 2025-Oct-19 22:00 0.968974601843 29.5107511 0.26120398203809 -0.5469109 76.5376 /T Sct 2025-Oct-19 22:30 0.969329685950 29.5111734 0.26119777917412 -0.4840282 76.6168 /T Sct 2025-Oct-19 23:00 0.969684775035 29.5115910 0.26119233300964 -0.4211449 76.6960 /T Sct 2025-Oct-19 23:30 0.970039869043 29.5120041 0.26118764354804 -0.3582615 76.7752 /T Sct 2025-Oct-20 00:00 0.970394967919 29.5124125 0.26118371078665 -0.2953786 76.8544 /T Sct $$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 '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. 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 = '2025 R2' QUANTITIES = '19,20,23,29' START_TIME = '2025-10-19 12:00' STEP_SIZE = '30 min' STOP_TIME = '2025-10-20'