******************************************************************************* JPL/HORIZONS Lemmon (C/2025 A6) 2025-Oct-01 08:31:59 Rec #:90004893 (+COV) Soln.date: 2025-Sep-30_13:39:34 # obs: 678 (2024-2025) IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): EPOCH= 2460890.5 ! 2025-Aug-03.0000000 (TDB) RMSW= n.a. EC= .9956645258067712 QR= .5299101045523907 TP= 2460988.0368068791 OM= 108.0975605274296 W= 132.9666096697441 IN= 143.66322402637 A= 122.2265618326168 MA= 359.9288583040018 ADIST= 243.9232135606811 PER= 1351.3149933688 N= .000729383 ANGMOM= .017689938 DAN= 3.29054 DDN= .630 L= 328.9525984 B= 25.6952698 MOID= .30837399 TP= 2025-Nov-08.5368068791 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 9.6 M2= n.a. k1= 14. k2= n.a. PHCOF= n.a. COMET comments 1: soln ref.= JPL#9, data arc: 2024-11-12 to 2025-09-30 2: k1=14.; ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Wed Oct 1 08:31:59 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Lemmon (C/2025 A6) {source: JPL#9} Center body name: Earth (399) {source: DE441} Center-site name: Vienna (since 1879) ******************************************************************************* Start time : A.D. 2025-Oct-01 00:00:00.0000 UT Stop time : A.D. 2025-Nov-10 00:00:00.0000 UT Step-size : 1440 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 16.339, 48.2319808, .283518 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 16.339, 4256.70269, 4734.30885 {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.250930.p251227 EOP coverage : DATA-BASED 1962-JAN-20 TO 2025-SEP-30. PREDICTS-> 2025-DEC-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= 2460890.5 ! 2025-Aug-03.0000000 (TDB) RMSW= n.a. EC= .9956645258067712 QR= .5299101045523907 TP= 2460988.0368068791 OM= 108.0975605274296 W= 132.9666096697441 IN= 143.66322402637 Equivalent ICRF heliocentric cartesian coordinates (au, au/d): X=-1.721722834908107E-01 Y= 1.618654389282255E+00 Z= 1.043821567821970E+00 VX= 8.835671575227275E-03 VY=-1.465314729028611E-02 VZ=-3.294089736113717E-03 Comet physical (GM= km^3/s^2; RAD= km): GM= n.a. RAD= n.a. M1= 9.6 M2= n.a. k1= 14. k2= n.a. PHCOF= n.a. ****************************************************************************************************************************************************************************** Date__(UT)__HR:MN R.A._____(ICRF)_____DEC T-mag N-mag delta deldot S-O-T /r S-T-O Sky_motion Sky_mot_PA RelVel-ANG Lun_Sky_Brt sky_SNR ****************************************************************************************************************************************************************************** $$SOE 2025-Oct-01 00:00 09 36 55.33 +39 51 04.0 9.671 n.a. 1.04597202213902 -57.4712244 58.1518 /L 58.6682 3.4172062 73.687019 -53.06630 n.a. n.a. 2025-Oct-02 00:00 09 43 59.58 +40 13 51.4 9.500 n.a. 1.01304719065205 -56.9299717 58.1672 /L 60.2920 3.6433389 74.841476 -51.91645 n.a. n.a. 2025-Oct-03 00:00 09 51 37.49 +40 36 19.9 9.325 n.a. 0.98046585725455 -56.2738714 58.1198 /L 61.9852 3.8911350 76.119027 -50.66680 n.a. n.a. 2025-Oct-04 00:00 m 09 59 52.57 +40 58 09.5 9.147 n.a. 0.94829858765909 -55.4873319 58.0035 /L 63.7521 4.1626299 77.530270 -49.30812 1.990 n.a. 2025-Oct-05 00:00 m 10 08 48.57 +41 18 55.1 8.966 n.a. 0.91662555573761 -54.5525728 57.8120 /L 65.5968 4.4598911 79.086330 -47.83036 2.451 n.a. 2025-Oct-06 00:00 m 10 18 29.41 +41 38 04.5 8.782 n.a. 0.88553786887139 -53.4494076 57.5387 /L 67.5232 4.7849302 80.798580 -46.22266 2.787 n.a. 2025-Oct-07 00:00 m 10 28 59.10 +41 54 57.6 8.596 n.a. 0.85513900924307 -52.1550642 57.1763 /L 69.5350 5.1395693 82.678191 -44.47339 3.230 n.a. 2025-Oct-08 00:00 m 10 40 21.51 +42 08 44.9 8.408 n.a. 0.82554635758214 -50.6440881 56.7180 /L 71.6349 5.5252487 84.735451 -42.57027 2.750 n.a. 2025-Oct-09 00:00 m 10 52 40.17 +42 18 26.2 8.218 n.a. 0.79689273256811 -48.8883986 56.1568 /L 73.8247 5.9427620 86.978798 -40.50056 2.353 n.a. 2025-Oct-10 00:00 m 11 05 57.88 +42 22 49.4 8.026 n.a. 0.76932783076447 -46.8575956 55.4865 /L 76.1043 6.3919034 89.413503 -38.25134 2.023 n.a. 2025-Oct-11 00:00 m 11 20 16.27 +42 20 30.7 7.834 n.a. 0.74301938913931 -44.5196369 54.7017 /L 78.4709 6.8710203 92.040005 -35.81003 1.757 n.a. 2025-Oct-12 00:00 m 11 35 35.27 +42 09 54.8 7.642 n.a. 0.71815381828549 -41.8420201 53.7992 /L 80.9184 7.3764742 94.851959 -33.16501 1.525 n.a. 2025-Oct-13 00:00 m 11 51 52.53 +41 49 18.2 7.452 n.a. 0.69493597525823 -38.7936073 52.7781 /L 83.4361 7.9020428 97.834225 -30.30659 1.289 n.a. 2025-Oct-14 00:00 m 12 09 02.94 +41 16 53.5 7.264 n.a. 0.67358767165065 -35.3472033 51.6415 /L 86.0070 8.4383313 100.96118 -27.22814 1.022 n.a. 2025-Oct-15 00:00 m 12 26 58.28 +40 30 57.1 7.079 n.a. 0.65434446759769 -31.4829204 50.3972 /L 88.6068 8.9723184 104.19592 -23.92747 0.712 n.a. 2025-Oct-16 00:00 m 12 45 27.22 +39 29 59.1 6.900 n.a. 0.63745032372333 -27.1922090 49.0588 /L 91.2025 9.4872186 107.49085 -20.40836 0.406 n.a. 2025-Oct-17 00:00 13 04 15.78 +38 12 54.6 6.727 n.a. 0.62314981984637 -22.4821870 47.6468 /L 93.7511 9.9628746 110.79014 -16.68202 n.a. n.a. 2025-Oct-18 00:00 13 23 08.22 +36 39 15.4 6.563 n.a. 0.61167794531743 -17.3796040 46.1883 /L 96.2000 10.376875 114.03404 -12.76824 n.a. n.a. 2025-Oct-19 00:00 13 41 48.23 +34 49 18.3 6.409 n.a. 0.60324792946819 -11.9335127 44.7166 /T 98.4879 10.706473 117.16444 -8.695981 n.a. n.a. 2025-Oct-20 00:00 14 00 00.27 +32 44 09.4 6.266 n.a. 0.59803814937208 -6.2156461 43.2690 /T 100.5477 10.931154 120.13065 -4.503007 n.a. n.a. 2025-Oct-21 00:00 14 17 30.76 +30 25 42.0 6.135 n.a. 0.59617967457905 -0.3177516 41.8837 /T 102.3110 11.035441 122.89428 -0.234492 n.a. n.a. 2025-Oct-22 00:00 14 34 08.87 +27 56 28.2 6.018 n.a. 0.59774627343408 5.6542340 40.5958 /T 103.7136 11.011285 125.43218 4.0594751 n.a. n.a. 2025-Oct-23 00:00 14 49 46.92 +25 19 24.8 5.914 n.a. 0.60274853086764 11.5884334 39.4330 /T 104.7023 10.859410 127.73715 8.3271293 n.a. n.a. 2025-Oct-24 00:00 15 04 20.25 +22 37 38.0 5.823 n.a. 0.61113307432902 17.3762208 38.4125 /T 105.2397 10.589205 129.81655 12.518516 n.a. n.a. 2025-Oct-25 00:00 15 17 46.95 +19 54 07.3 5.746 n.a. 0.62278693849457 22.9205810 37.5392 /T 105.3079 10.217206 131.68958 16.588644 n.a. n.a. 2025-Oct-26 00:00 15 30 07.26 +17 11 33.6 5.681 n.a. 0.63754613530261 28.1421587 36.8060 /T 104.9085 9.7646027 133.38380 20.499820 n.a. n.a. 2025-Oct-27 00:00 15 41 23.04 +14 32 10.9 5.628 n.a. 0.65520684513573 32.9822629 36.1960 /T 104.0608 9.2544382 134.93170 24.222899 n.a. n.a. 2025-Oct-28 00:00 15 51 37.25 +11 57 43.0 5.586 n.a. 0.67553746643902 37.4029260 35.6860 /T 102.7970 8.7091175 136.36774 27.737473 n.a. n.a. 2025-Oct-29 00:00 16 00 53.52 +09 29 23.5 5.554 n.a. 0.69829001215494 41.3847326 35.2499 /T 101.1580 8.1485993 137.72599 31.031194 n.a. n.a. 2025-Oct-30 00:00 16 09 15.80 +07 07 59.5 5.532 n.a. 0.72320984248435 44.9233799 34.8614 /T 99.1883 7.5893894 139.03841 34.098549 n.a. n.a. 2025-Oct-31 00:00 16 16 48.15 +04 53 55.1 5.520 n.a. 0.75004327000999 48.0258630 34.4968 /T 96.9325 7.0442321 140.33374 36.939402 n.a. n.a. 2025-Nov-01 00:00 m 16 23 34.58 +02 47 17.2 5.517 n.a. 0.77854301970384 50.7069247 34.1355 /T 94.4336 6.5222999 141.63674 39.557532 n.a. n.a. 2025-Nov-02 00:00 m 16 29 38.92 +00 47 59.6 5.523 n.a. 0.80847181242487 52.9861268 33.7613 /T 91.7310 6.0296663 142.96781 41.959342 n.a. n.a. 2025-Nov-03 00:00 m 16 35 04.80 -01 04 13.0 5.538 n.a. 0.83960447267918 54.8856575 33.3617 /T 88.8605 5.5698904 144.34270 44.152819 n.a. n.a. 2025-Nov-04 00:00 m 16 39 55.61 -02 49 41.4 5.562 n.a. 0.87172897997382 56.4288392 32.9278 /T 85.8542 5.1445967 145.77239 46.146767 n.a. n.a. 2025-Nov-05 00:00 m 16 44 14.51 -04 28 49.5 5.595 n.a. 0.90464683495048 57.6392173 32.4537 /T 82.7413 4.7539879 147.26311 47.950293 n.a. n.a. 2025-Nov-06 00:00 m 16 48 04.39 -06 02 03.0 5.639 n.a. 0.93817303476166 58.5400888 31.9363 /T 79.5480 4.3972642 148.81642 49.572524 n.a. n.a. 2025-Nov-07 00:00 m 16 51 27.95 -07 29 47.1 5.692 n.a. 0.97213587057274 59.1543323 31.3743 /T 76.2983 4.0729510 150.42944 51.022485 n.a. n.a. 2025-Nov-08 00:00 m 16 54 27.68 -08 52 26.8 5.754 n.a. 1.00637668411192 59.5044147 30.7680 /T 73.0144 3.7791457 152.09527 52.309090 n.a. n.a. 2025-Nov-09 00:00 m 16 57 05.87 -10 10 25.4 5.827 n.a. 1.04074965318512 59.6124683 30.1188 /T 69.7165 3.5136980 153.80344 53.441192 n.a. n.a. 2025-Nov-10 00:00 m 16 59 24.65 -11 24 04.9 5.909 n.a. 1.07512162115966 59.5003544 29.4291 /T 66.4234 3.2743413 155.54065 54.427646 n.a. n.a. $$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. SOLAR PRESENCE (OBSERVING SITE) Time tag is followed by a blank, then a solar-presence symbol: '*' Daylight (refracted solar upper-limb on or above apparent horizon) 'C' Civil twilight/dawn 'N' Nautical twilight/dawn 'A' Astronomical twilight/dawn ' ' Night OR geocentric ephemeris LUNAR PRESENCE (OBSERVING SITE) The solar-presence symbol is immediately followed by a lunar-presence symbol: 'm' Refracted upper-limb of Moon on or above apparent horizon ' ' Refracted upper-limb of Moon below apparent horizon OR geocentric ephemeris 'R.A._____(ICRF)_____DEC' = Astrometric right ascension and declination of the target center with respect to the observing site (coordinate origin) in the reference frame of the planetary ephemeris (ICRF). Compensated for down-leg light-time delay aberration. Units: RA in hours-minutes-seconds of time, HH MM SS.ff{ffff} DEC in degrees-minutes-seconds of arc, sDD MN SC.f{ffff} 'T-mag N-mag' = Comets' apparent visual total magnitude ("T-mag") and nuclear magnitude ("N-mag") using the standard IAU model: T-mag= M1 + 5*log10(delta) + k1*log10(r) N-mag= M2 + 5*log10(delta) + k2*log10(r) + phcof*beta Units: MAGNITUDES '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 'S-T-O' = The Sun-Target-Observer angle; the interior vertex angle at target center formed by a vector from the target to the apparent center of the Sun (at reflection time on the target) and the apparent vector from target to the observer at print-time. Slightly different from true PHASE ANGLE (requestable separately) at the few arcsecond level in that it includes stellar aberration on the down-leg from target to observer. Units: DEGREES 'Sky_motion Sky_mot_PA RelVel-ANG' = Total apparent angular rate of the target in the plane-of-sky. "Sky_mot_PA" is the position angle of the target's direction of motion in the plane-of-sky, measured counter-clockwise from the apparent of-date north pole direction. "RelVel-ANG" is the flight path angle of the target's relative motion with respect to the observer's line-of-sight, in the range [-90,+90], where positive values indicate motion away from the observer, negative values are toward the observer: -90 = target is moving directly toward the observer 0 = target is moving at right angles to the observer's line-of-sight +90 = target is moving directly away from the observer UNITS: ARCSECONDS/MINUTE, DEGREES, DEGREES 'Lun_Sky_Brt sky_SNR' = Sky brightness due to moonlight scattered by Earth's atmosphere at the target's position in the sky. "sky_SNR" is the visual signal-to-noise ratio (SNR) of the target's surface brightness relative to background sky. Output only for topocentric Earth observers when both the Moon and target are above the local horizon and the Sun is in astronomical twilight (or further) below the horizon, and the target is not the Moon or Sun. If all conditions are not met, "n.a." is output. Galactic brightness, local sky light-pollution and weather are NOT considered. Lunar opposition surge is considered. The value returned is accurate under ideal conditions at the approximately 8-23% level, so is a useful but not definitive value. If the target-body radius is also known, "sky_SNR" is output. This is the approximate visual signal-to-noise ratio of the target's brightness divided by lunar sky brightness. When sky_SNR < 1, the target is dimmer than the ideal moonlight-scattering background sky, so unlikely to be detectable at visual wavelengths. In practice, visibility requires sky_SNR > 1 and a detector sensitive enough to reach the target's magnitude, even if it isn't washed out by moonlight. When relating magnitudes and brightness values, keep in mind their logarithmic relationship m2-m1 = -2.5*log_10(b2/b1). UNITS: VISUAL MAGNITUDES / ARCSECOND^2, and unitless ratio 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 ******************************************************************************************************************************************************************************