API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: Jul 19, 2026 INTEGRAL Spacecraft (gamma-ray observatory) -198 http://www.esa.int/export/esaMI/Integral/ESAR0RPV16D_0.html INTEGRAL (INTErnational Gamma-Ray Astrophysics Laboratory): Deployment (Proton) = Oct 17, 2002 Diameter/length (meters) = 3.7/5 m ORBITAL DATA: Inclination = 51 degrees Orbital period = ~72 hours Apogee altitude = ~ 155000 km Perigee altitude = ~9,000 km The spacecraft will spend most of its time above an altitude of 40,000 km (outside Earth's radiation belts), thus minimizing background radiation effects. Will study black holes, neutron stars, active galactic nuclei and supernovae, providing information on formation of new chemical elements and gamma-ray bursts. ESA mission. WEIGHTS & PROPULSION: Launch Mass: 4 tonnes SPACECRAFT TRAJECTORY Launch to 2005-Jan-31 JPL Multi-Mission Navigation Team, merged solutions: OD0018_021017, OD0020_021019, OD0022_021021, OD0030_021029, OD0035_021108, OD0037_021119, OD0040_021129, OD0042_021206, OD0045_021216, OD0047_021222, OD0051_030102, OD0053_030108, OD0057_030120, OD0060_030127, OD0062_030207, OD0066_030219, OD0068_030228, OD0071_030310, OD0075_030321, OD0079_030402, OD0084_030416, OD0089_030502, OD0090_030505, OD0097_030529, OD0105_030624, OD0113_030721, OD0122_030817, OD0127_030907, OD0131_030919, OD0134_031001, OD0141_031022, OD0148_031117, OD0153_031201, OD0157_031212, OD0163_031230, OD0169_040126, OD0179_040222, OD0182_040302, OD0184_040309, OD0192_040401, OD0202_040428, OD0209_040521, OD0212_040530, OD0219_040620, OD0227_040714, OD0236_040810, OD0240_040822, OD0246_040906, OD0251_040927, OD0256_041015, OD0260_041101, OD0267_041123, OD0277_041215, OD0285_050101. 2005-Jan-31 to 2015-Jan-01: JSpOC TLEs 2015-Jan-01 to 2015-Dec-02: ESA-provided ephemeris 2015-Dec-02 to PRESENT : JSpOC TLEs NOTE: The ESA ephemeris is used for much of 2015 since TLE's issued by JSpOC were based on an obsolete predictive ephemeris for the spacecraft that did not reflect January 2015 maneuvering of INTEGRAL to a different orbit. http://sci.esa.int/integral/55345-integral-manoeuvres-for-the-future/ ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Sun Jul 19 09:25:43 2026 Pasadena, USA / Horizons ******************************************************************************* Target body name: INTEGRAL (spacecraft) (-198) {source: integral_merged} Center body name: Earth (399) {source: DE441} Center-site name: Deep Random Survey, El Sauce ******************************************************************************* Start time : A.D. 2025-Sep-04 00:00:00.0000 UT Stop time : A.D. 2025-Sep-18 00:00:00.0000 UT Step-size : 10 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 289.1467, -30.5262851, 1.74234 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 289.1467,5500.35467,-3221.64998 {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 : Earth 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 Atmos refraction: NO (AIRLESS) RA format : HMS Time format : CAL Calendar mode : Mixed Julian/Gregorian RTS-only print : NO EOP file : eop.260717.p261013 EOP coverage : DATA-BASED 1962-JAN-20 TO 2026-JUL-17. PREDICTS-> 2026-OCT-12 Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s Table cut-offs 1: Elevation ( 0.0deg=YES),Airmass (>38.000=NO), Daylight (YES) Table cut-offs 2: Solar elongation ( 12.0,180.0=YES),Local Hour Angle( 0.0=NO ) Table cut-offs 3: RA/DEC angular rate ( 0.0=NO ) *************************************************************************************************************************************************************************************************************************************************** Date__(UT)__HR:MN R.A._____(ICRF)_____DEC Azi____(a-app)___Elev APmag S-brt r rdot delta deldot S-O-T /r S-T-O T-O-M/MN_Illu% RA_3sigma DEC_3sigma Sky_motion Sky_mot_PA RelVel-ANG *************************************************************************************************************************************************************************************************************************************************** $$SOE >..... Elevation Cut-off Requested .....< 2025-Sep-04 04:40 m 10 11 54.40 -62 28 14.9 175.615979 3.436951 n.a. n.a. 1.008487144015 7.1437866 0.00006062462895 -3.7857919 70.1238 /L 109.8727 88.6/ 84.9519 n.a. n.a. 9544.4048 207.92961 -28.42435 2025-Sep-04 04:50 m 04 07 22.14 -75 23 48.7 162.946582 32.845844 n.a. n.a. 1.008514506180 6.4111746 0.00004994713298 -1.2827928 99.7934 /L 80.2034 73.8/ 84.9908 n.a. n.a. 12563.690 298.35193 -9.596881 2025-Sep-04 05:00 m 01 01 47.92 -46 50 36.6 134.748286 63.017451 n.a. n.a. 1.008538227820 5.3985529 0.00005122462958 1.8181762 131.6325 /L 48.3648 63.4/ 85.0304 n.a. n.a. 11327.655 342.10918 14.534325 2025-Sep-04 05:10 e 00 29 27.27 -21 32 23.1 63.895667 71.871215 n.a. n.a. 1.008557903735 4.4296603 0.00006268509105 3.6394046 152.4741 /L 27.5240 62.4/ 85.0707 n.a. n.a. 7519.5969 348.08832 32.569186 2025-Sep-04 05:20 m 00 16 13.44 -05 01 10.1 25.473973 62.097297 n.a. n.a. 1.008573998614 3.6203182 0.00007889314835 4.3120128 158.9637 /L 21.0349 65.3/ 85.1117 n.a. n.a. 4833.5707 349.81955 43.090768 2025-Sep-04 05:30 m 00 08 37.41 +05 55 52.0 11.961158 52.744524 n.a. n.a. 1.008587178329 2.9730832 0.00009663739825 4.4834673 156.8175 /L 23.1809 68.5/ 85.1535 n.a. n.a. 3308.4323 350.47557 49.239436 2025-Sep-04 05:40 m 00 03 24.88 +13 40 44.2 4.769446 45.526382 n.a. n.a. 1.008598037908 2.4585303 0.00011462427263 4.4637270 152.6179 /L 27.3799 71.3/ 85.1960 n.a. n.a. 2418.0390 350.70262 53.109500 2025-Sep-04 05:50 t 23 59 26.83 +19 29 29.8 359.926065 39.837229 n.a. n.a. 1.008607046699 2.0459095 0.00013236421804 4.3723062 148.5715 /L 31.4254 73.6/ 85.2393 n.a. n.a. 1861.2427 350.70929 55.741347 2025-Sep-04 06:00 m 23 56 12.78 +24 03 14.0 356.231322 35.179516 n.a. n.a. 1.008614562003 1.7105157 0.00014967788205 4.2560883 145.0486 /L 34.9473 75.5/ 85.2833 n.a. n.a. 1489.8056 350.58907 57.653087 2025-Sep-04 06:10 m 23 53 27.26 +27 45 32.6 353.204287 31.234191 n.a. n.a. 1.008620854862 1.4339117 0.00016650990695 4.1342678 142.0278 /L 37.9671 77.1/ 85.3282 n.a. n.a. 1228.4312 350.39335 59.118324 2025-Sep-04 06:20 m 23 51 01.61 +30 50 51.9 350.613405 27.797276 n.a. n.a. 1.008626132697 1.2025975 0.00018285622469 4.0148378 139.4255 /L 40.5686 78.5/ 85.3738 n.a. n.a. 1036.4267 350.15395 60.291101 2025-Sep-04 06:30 m 23 48 50.59 +33 28 32.1 348.332218 24.734355 n.a. n.a. 1.008630556365 1.0066727 0.00019873390040 3.9009989 137.1624 /L 42.8307 79.7/ 85.4203 n.a. n.a. 890.40292 349.89219 61.263310 2025-Sep-04 06:40 m 23 46 50.89 +35 44 52.4 346.285027 21.953814 n.a. n.a. 1.008634252435 0.8388048 0.00021416799143 3.7938200 135.1747 /L 44.8174 80.7/ 85.4675 n.a. n.a. 776.16324 349.62318 62.092559 2025-Sep-04 06:50 m 23 45 00.29 +37 44 19.9 344.423247 19.391249 n.a. n.a. 1.008637321924 0.6934910 0.00022918565640 3.6934095 133.4125 /L 46.5787 81.6/ 85.5156 n.a. n.a. 684.67893 349.35813 62.816506 2025-Sep-04 07:00 m 23 43 17.27 +39 30 08.6 342.713950 17.000161 n.a. n.a. 1.008639846549 0.5665436 0.00024381351596 3.5994523 131.8371 /L 48.1532 82.4/ 85.5645 n.a. n.a. 609.97484 349.10574 63.460644 2025-Sep-04 07:10 m 23 41 40.78 +41 04 43.7 341.133820 14.746201 n.a. n.a. 1.008641893242 0.4547309 0.00025807652686 3.5114636 130.4183 /L 49.5713 83.1/ 85.6142 n.a. n.a. 547.96013 348.87299 64.042736 2025-Sep-04 07:20 m 23 40 10.02 +42 29 56.1 339.665753 12.603494 n.a. n.a. 1.008643517449 0.3555256 0.00027199757491 3.4289102 129.1320 /L 50.8567 83.8/ 85.6647 n.a. n.a. 495.75120 348.66568 64.575451 2025-Sep-04 07:30 m 23 38 44.44 +43 47 12.4 338.296823 10.552234 n.a. n.a. 1.008644765584 0.2669267 0.00028559740982 3.3512673 127.9591 /L 52.0288 84.3/ 85.7160 n.a. n.a. 451.26353 348.48875 65.067996 2025-Sep-04 07:40 m 23 37 23.60 +44 57 41.4 337.017029 8.577043 n.a. n.a. 1.008645676865 0.1873311 0.00029889473747 3.2780439 126.8840 /L 53.1030 84.9/ 85.7681 n.a. n.a. 412.95679 348.34654 65.527155 2025-Sep-04 07:50 m 23 36 07.19 +46 02 18.8 335.818470 6.665846 n.a. n.a. 1.008646284719 0.1154411 0.00031190637882 3.2087924 125.8941 /L 54.0921 85.3/ 85.8209 n.a. n.a. 379.67068 348.24289 65.957967 2025-Sep-04 08:00 m 23 34 54.97 +47 01 50.0 334.694806 4.809067 n.a. n.a. 1.008646617861 0.0501955 0.00032464744971 3.1431106 124.9788 /L 55.0067 85.8/ 85.8746 n.a. n.a. 350.51619 348.18130 66.364190 2025-Sep-04 08:10 m 23 33 46.75 +47 56 52.5 333.640876 2.999056 n.a. n.a. 1.008646701132 -0.0092814 0.00033713153974 3.0806395 124.1292 /L 55.8555 86.2/ 85.9291 n.a. n.a. 324.80183 348.16496 66.748620 2025-Sep-04 08:20 m 23 32 42.37 +48 47 57.9 332.652440 1.229662 n.a. n.a. 1.008646556171 -0.0637182 0.00034937087997 3.0210604 123.3379 /L 56.6461 86.5/ 85.9843 n.a. n.a. 301.98244 348.19680 67.113309 2025-Sep-04 08:30 m 23 31 41.72 +49 35 32.8 331.725982 -0.504084 n.a. n.a. 1.008646201934 -0.1137261 0.00036137649539 2.9640902 122.5986 /L 57.3847 86.9/ 86.0402 n.a. n.a. 281.62305 348.27952 67.459728 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Solar Elongation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2025-Sep-12 04:10 t 10 22 15.63 -60 57 21.6 176.476054 1.803229 n.a. n.a. 1.006464438225 7.4359161 0.00006227357582 -3.8709215 66.1728 /L 113.8238 119.0/ 74.4454 n.a. n.a. 9208.7946 204.99192 -29.17959 2025-Sep-12 04:20 m 04 48 41.47 -77 06 28.3 164.964534 30.488244 n.a. n.a. 1.006493229706 6.8187304 0.00005094920921 -1.5186134 95.9063 /L 84.0903 100.9/ 74.3834 n.a. n.a. 12259.891 287.95939 -11.37109 2025-Sep-12 04:30 m 01 03 37.99 -50 04 08.6 140.709152 61.376381 n.a. n.a. 1.006518709335 5.8549830 0.00005116763886 1.5649926 129.2876 /L 50.7096 77.6/ 74.3225 n.a. n.a. 11474.487 341.63067 12.436969 2025-Sep-12 04:40 e 00 28 53.66 -24 07 34.0 70.607530 73.588691 n.a. n.a. 1.006540235310 4.8882634 0.00006183459737 3.4981925 154.2037 /L 25.7942 60.3/ 74.2625 n.a. n.a. 7781.5539 348.25117 31.025825 2025-Sep-12 04:50 m 00 15 18.05 -06 58 49.3 25.887790 64.136914 n.a. n.a. 1.006558139741 4.0602442 0.00007764901266 4.2470773 166.1553 /L 13.8435 51.2/ 74.2035 n.a. n.a. 5012.9609 350.07736 42.071225 2025-Sep-12 05:00 m 00 07 38.33 +04 22 22.1 11.413298 54.385009 n.a. n.a. 1.006573037373 3.3878716 0.00009521749065 4.4546507 165.4806 /L 14.5186 46.9/ 74.1455 n.a. n.a. 3419.5152 350.74780 48.539298 2025-Sep-12 05:10 m 00 02 26.45 +12 22 27.6 4.044570 46.867872 n.a. n.a. 1.006585511412 2.8477678 0.00011313032635 4.4519196 160.4460 /L 19.5525 44.9/ 74.0884 n.a. n.a. 2489.2656 350.97330 52.597754 2025-Sep-12 05:20 t 23 58 30.31 +18 21 17.3 359.170865 40.969558 n.a. n.a. 1.006596034737 2.4113287 0.00013084527317 4.3689749 155.5944 /L 24.4033 44.1/ 74.0322 n.a. n.a. 1909.4636 350.97576 55.345916 2025-Sep-12 05:30 m 23 55 18.54 +23 02 02.9 355.482113 36.159727 n.a. n.a. 1.006604973120 2.0544160 0.00014815897507 4.2572171 151.4838 /L 28.5130 43.9/ 73.9769 n.a. n.a. 1524.1240 350.85194 57.333577 2025-Sep-12 05:40 m 23 52 35.38 +26 49 29.7 352.470609 32.098650 n.a. n.a. 1.006612606954 1.7585691 0.00016500444089 4.1378381 148.0313 /L 31.9645 44.1/ 73.9224 n.a. n.a. 1253.8979 350.65404 58.850917 2025-Sep-12 05:50 m 23 50 12.07 +29 58 43.2 349.896976 28.570099 n.a. n.a. 1.006619152438 1.5100693 0.00018137159626 4.0197744 145.1006 /L 34.8943 44.4/ 73.8688 n.a. n.a. 1055.9845 350.41398 60.060979 2025-Sep-12 06:00 m 23 48 03.34 +32 39 27.2 347.632296 25.432203 n.a. n.a. 1.006624778203 1.2987547 0.00019727423472 3.9067011 142.5791 /L 37.4148 44.8/ 73.8160 n.a. n.a. 905.85298 350.15298 61.060795 2025-Sep-12 06:10 m 23 46 05.86 +34 58 15.5 345.600150 22.588626 n.a. n.a. 1.006629617548 1.1170439 0.00021273555353 3.7999394 140.3822 /L 39.6108 45.3/ 73.7640 n.a. n.a. 788.65823 349.88598 61.911051 2025-Sep-12 06:20 m 23 44 17.43 +36 59 44.9 343.751832 19.971860 n.a. n.a. 1.006633777276 0.9592154 0.00022778161784 3.6997381 138.4467 /L 41.5454 45.7/ 73.7128 n.a. n.a. 694.98576 349.62405 62.651331 2025-Sep-12 06:30 m 23 42 36.54 +38 47 15.9 342.054504 17.533286 n.a. n.a. 1.006637344075 0.8208954 0.00024243838927 3.6058633 136.7250 /L 43.2662 46.2/ 73.6622 n.a. n.a. 618.62127 349.37572 63.308380 2025-Sep-12 06:40 m 23 41 02.11 +40 23 18.1 340.484998 15.237064 n.a. n.a. 1.006640389154 0.6986956 0.00025673042044 3.5178786 135.1807 /L 44.8097 46.7/ 73.6123 n.a. n.a. 555.32009 349.14783 63.900801 2025-Sep-12 06:50 m 23 39 33.37 +41 49 45.8 339.026367 13.056242 n.a. n.a. 1.006642971664 0.5899581 0.00027068034693 3.4352803 133.7855 /L 46.2040 47.1/ 73.5631 n.a. n.a. 502.09642 348.94607 64.441847 2025-Sep-12 07:00 m 23 38 09.76 +43 08 08.1 337.665830 10.970215 n.a. n.a. 1.006645141235 0.4925722 0.00028430876312 3.3575622 132.5171 /L 47.4716 47.6/ 73.5144 n.a. n.a. 456.79591 348.77525 64.941137 2025-Sep-12 07:10 m 23 36 50.86 +44 19 35.5 336.393512 8.963001 n.a. n.a. 1.006646939901 0.4048432 0.00029763427929 3.2842449 131.3575 /L 48.6304 48.0/ 73.4663 n.a. n.a. 417.82932 348.63959 65.405753 2025-Sep-12 07:20 m 23 35 36.35 +45 25 04.9 335.201622 7.022060 n.a. n.a. 1.006648403562 0.3253956 0.00031067365869 3.2148884 130.2923 /L 49.6949 48.4/ 73.4187 n.a. n.a. 384.00130 348.54285 65.840957 2025-Sep-12 07:30 m 23 34 25.99 +46 25 22.9 334.083911 5.137450 n.a. n.a. 1.006649563117 0.2531025 0.00032344198373 3.1490951 129.3094 /L 50.6770 48.7/ 73.3716 n.a. n.a. 354.39722 348.48842 66.250673 2025-Sep-12 07:40 m 23 33 19.59 +47 21 08.0 333.035296 3.301230 n.a. n.a. 1.006650445350 0.1870324 0.00033595282614 3.0865093 128.3989 /L 51.5867 49.1/ 73.3249 n.a. n.a. 328.30654 348.47940 66.637824 2025-Sep-12 07:50 m 23 32 17.00 +48 12 52.2 332.051605 1.507013 n.a. n.a. 1.006651073630 0.1264086 0.00034821840906 3.0268139 127.5526 /L 52.4323 49.4/ 73.2786 n.a. n.a. 305.16972 348.51862 67.004561 2025-Sep-12 08:00 m 23 31 18.10 +49 01 02.8 331.129380 -0.250361 n.a. n.a. 1.006651468467 0.0705786 0.00036024975581 2.9697275 126.7632 /L 53.2210 49.8/ 73.2326 n.a. n.a. 284.54072 348.60869 67.352433 >..... Elevation Cut-off Requested .....< >..... Daylight Cut-off Requested .....< >..... Solar Elongation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< >..... Elevation Cut-off Requested .....< $$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 condition code: '*' 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 WITH TARGET RISE/TRANSIT/SET EVENT MARKER (OBSERVING SITE) The solar-presence code column is immediately followed by another marker: 'm' Refracted upper-limb of Moon on or above apparent horizon ' ' Refracted upper-limb of Moon below apparent horizon OR geocentric The lunar presence marker (an ongoing state) can be over-ridden by a target event marker if an event has occurred since the last output step: 'r' Rise (target body on or went above cut-off RTS elevation) 'e' Elevation max (target body maximum elevation angle has occurred) 't' Transit (target body at or passed through observer meridian) 's' Set (target body on or went below cut-off RTS elevation) RTS MARKERS (TVH) Rise and set are with respect to the reference ellipsoid true visual horizon defined by the elevation cut-off angle. Horizon dip and yellow-light refraction (Earth only) are considered. Accuracy is < or = to twice the requested search step-size. '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} 'Azi____(a-app)___Elev' = Airless apparent azimuth and elevation of target center. Compensated for light-time, the gravitational deflection of light, stellar aberration, precession and nutation. Azimuth is measured clockwise from north: North(0) -> East(90) -> South(180) -> West(270) -> North (360) Elevation angle is with respect to a plane perpendicular to the reference surface local zenith direction. TOPOCENTRIC ONLY. Units: DEGREES 'APmag S-brt' = The targets' approximate apparent visual magnitude and surface brightness. For planets and natural satellites, output is restricted to solar phase angles covered by observational data. Outside the observed phase angle range, "n.a." may be output to avoid extrapolation beyond the limit of model validity. For Earth-based observers, the estimated dimming due to atmospheric absorption (extinction) is available as a separate, requestable quantity. Surface brightness is the average airless visual magnitude of a square-arcsecond of the illuminated portion of the apparent disk. It is computed only if the target radius is known. Units: MAGNITUDES & MAGNITUDES PER SQUARE ARCSECOND '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 '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 'T-O-M/MN_Illu%' = Target-Observer-Moon LUNAR ELONGATION angle and illuminated percentage. The apparent lunar elongation angle between target body center and Moon center, seen from the observing site, along with fraction of the lunar disk illuminated by the Sun. A negative lunar elongation angle indicates the target center is behind the Moon. Units: DEGREES & PERCENT 'RA_3sigma DEC_3sigma' = Uncertainty in Right-Ascension and Declination. Output values are the formal +/- 3 standard-deviations (sigmas) around nominal position. Units: ARCSECONDS '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 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 Inquiries : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************