API VERSION: 1.2 API SOURCE: NASA/JPL Horizons API ******************************************************************************* Revised: Dec 09, 2024 James Webb Space Telescope / (E-S L2) -170 https://www.jwst.nasa.gov/index.html https://www.youtube.com/watch?v=bTxLAGchWnA The James Webb Space Telescope ("JWST" or "Webb") is a space-based infrared observatory and NASA's successor to the Hubble Space Telescope. Launched by Ariane 5 booster on 2021-Dec-25 @ 12:20 UTC from the ELA-3 launch complex near Korou, French Guiana. After launch, the telescope will deploy during its 30-day, 1.5 million km journey to halo orbit at the second Earth-Sun Lagrange point (E-S L2). Mission duration is nominally 5-10 years. GOALS - Search for the first galaxies or luminous objects formed after the Big Bang - Determine how galaxies evolved from their formation until now - Observe the formation of stars from the first stages to the formation of planetary systems - Measure the physical and chemical properties of planetary systems, including our own Solar System, investigating the potential for life in those systems. TELESCOPE * total launch mass : ~6200 kg (observatory, fuel, launch adaptor) * primary mirror : 25 m^2 mass : 705 kg material : beryllium coated w/48.25 grams gold (golf-ball size) segment mass : 20.1 kg, 39.48 kg for entire segment assembly No. of segments : 18 * focal length : 131.4 meters * optical resolution: 0.1 arcseconds * wavelength : 0.6 - 28.5 microns * size of sun shield: 21.197 m x 14.162 m * Sun shield layers : 1: Max temp 283K, 231 deg. F. 5: Max temp 221K, -80 F Min temp 36K, -394 F * Operating temp : < 50K (-370 deg. F) INSTRUMENTS - Near Infrared Camera (NIRCam) - Near Infrared Spectrograph (NIRSpec) - Mid Infrared Instrument (MIRI) - Fine Guidance Sensors/Near Infrared Imager & Slitless Spectrograph (FGS/NIRISS) TRAJECTORY MCC1A (65-minute engine burn) began 2021-Dec-26 12:50 UTC, completed 01:55 UTC. MCC1B (09:27 engine burn) began 2021-Dec-28 00:20 UTC, completed 00:29:27 UTC. MCC2 (04:57 engine burn) began 2022-Jan-24 19:00 UTC, completed 19:04:57 UTC. Concatenation of reconstructed trajectory solutions (as-flown) from Goddard Flight Dynamics Facility (FDF), based on tracking data through December 08, with prediction thereafter. Trajectory files Start (TDB) End (TDB) ---------------------------------------- ----------------- ----------------- DEFINITIVE_EPHEMERIS_202135913-2024336 2021-Dec-25 13:01 2024-Dec-09 00:01 28D_BURN_PREDICT_SK_2024344000000_06U 2024-Dec-09 00:01 2025-Jan-06 00:01 5Y_SCHEDULE_2024344000000_06U.V0.1 2025-Jan-06 00:01 2029-Dec-08 23:59 ******************************************************************************* ******************************************************************************* Ephemeris / API_USER Thu Dec 12 02:21:54 2024 Pasadena, USA / Horizons ******************************************************************************* Target body name: James Webb Space Telescope (spacecraft) (-170) {source: JWST_merged} Center body name: Earth (399) {source: DE441} Center-site name: VdS Remote Observatory, Hakos ******************************************************************************* Start time : A.D. 2024-Nov-30 00:00:00.0000 UT Stop time : A.D. 2024-Dec-01 00:00:00.0000 UT Step-size : 10 minutes ******************************************************************************* Target pole/equ : undefined Target radii : undefined Center geodetic : 16.3613, -23.2365766, 1.8515 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 16.3613,5865.52307,-2501.54567 {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.241211.p250309 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-DEC-11. PREDICTS-> 2025-MAR-08 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 2024-Nov-30 00:00 05 45 41.07 +13 55 16.9 1.702433 52.816548 n.a. n.a. 0.996731049673 -0.1976081 0.01114340850082 0.0142884 159.2360 /L 20.5370 145.2/ 1.5713 n.a. n.a. 2.6321714 255.03154 2.3022909 2024-Nov-30 00:10 t 05 45 39.32 +13 55 09.9 357.664916 52.805722 n.a. n.a. 0.996730257175 -0.1975784 0.01114350230905 0.0324910 159.2479 /L 20.5252 145.3/ 1.5488 n.a. n.a. 2.6407959 254.33124 5.2134473 2024-Nov-30 00:20 05 45 37.58 +13 55 02.6 353.645997 52.632658 n.a. n.a. 0.996729464797 -0.1975486 0.01114366909276 0.0506736 159.2598 /L 20.5135 145.4/ 1.5266 n.a. n.a. 2.6439180 253.59927 8.0925831 2024-Nov-30 00:30 05 45 35.84 +13 54 54.9 349.677623 52.299596 n.a. n.a. 0.996728672538 -0.1975189 0.01114390870166 0.0688012 159.2716 /L 20.5018 145.5/ 1.5048 n.a. n.a. 2.6415933 252.83255 10.937851 2024-Nov-30 00:40 05 45 34.12 +13 54 46.8 345.789194 51.810741 n.a. n.a. 0.996727880398 -0.1974892 0.01114422084485 0.0868388 159.2833 /L 20.4902 145.6/ 1.4834 n.a. n.a. 2.6338934 252.02765 13.747499 2024-Nov-30 00:50 05 45 32.41 +13 54 38.5 342.006290 51.172001 n.a. n.a. 0.996727088378 -0.1974595 0.01114460509143 0.1047516 159.2949 /L 20.4787 145.7/ 1.4623 n.a. n.a. 2.6209078 251.18076 16.519853 2024-Nov-30 01:00 05 45 30.71 +13 54 29.8 338.349831 50.390661 n.a. n.a. 0.996726296477 -0.1974298 0.01114506087130 0.1225049 159.3064 /L 20.4673 145.8/ 1.4416 n.a. n.a. 2.6027444 250.28766 19.253295 2024-Nov-30 01:10 05 45 29.05 +13 54 20.8 334.835689 49.475009 n.a. n.a. 0.996725504694 -0.1974001 0.01114558747633 0.1400646 159.3178 /L 20.4560 145.9/ 1.4213 n.a. n.a. 2.5795303 249.34364 21.946238 2024-Nov-30 01:20 05 45 27.40 +13 54 11.5 331.474734 48.433967 n.a. n.a. 0.996724713031 -0.1973704 0.01114618406174 0.1573968 159.3290 /L 20.4449 146.0/ 1.4014 n.a. n.a. 2.5514136 248.34342 24.597098 2024-Nov-30 01:30 05 45 25.79 +13 54 01.9 328.273209 47.276755 n.a. n.a. 0.996723921487 -0.1973408 0.01114684964782 0.1744680 159.3401 /L 20.4339 146.1/ 1.3819 n.a. n.a. 2.5185639 247.28110 27.204260 2024-Nov-30 01:40 05 45 24.22 +13 53 51.9 325.233319 46.012600 n.a. n.a. 0.996723130062 -0.1973111 0.01114758312182 0.1912453 159.3510 /L 20.4231 146.2/ 1.3628 n.a. n.a. 2.4811746 246.15003 29.766036 2024-Nov-30 01:50 05 45 22.68 +13 53 41.7 322.353940 44.650511 n.a. n.a. 0.996722338757 -0.1972814 0.01114838324017 0.2076965 159.3617 /L 20.4125 146.3/ 1.3441 n.a. n.a. 2.4394643 244.94273 32.280623 2024-Nov-30 02:00 05 45 21.19 +13 53 31.1 319.631334 43.199109 n.a. n.a. 0.996721547570 -0.1972517 0.01114924863097 0.2237898 159.3723 /L 20.4020 146.4/ 1.3258 n.a. n.a. 2.3936794 243.65077 34.746051 2024-Nov-30 02:10 05 45 19.74 +13 53 20.3 317.059823 41.666513 n.a. n.a. 0.996720756502 -0.1972220 0.01115017779670 0.2394943 159.3826 /L 20.3918 146.5/ 1.3079 n.a. n.a. 2.3440970 242.26463 37.160126 2024-Nov-30 02:20 05 45 18.34 +13 53 09.2 314.632389 40.060280 n.a. n.a. 0.996719965554 -0.1971924 0.01115116911716 0.2547799 159.3927 /L 20.3818 146.6/ 1.2904 n.a. n.a. 2.2910276 240.77359 39.520359 2024-Nov-30 02:30 05 45 17.00 +13 52 57.9 312.341163 38.387368 n.a. n.a. 0.996719174724 -0.1971627 0.01115222085270 0.2696170 159.4025 /L 20.3720 146.7/ 1.2733 n.a. n.a. 2.2348197 239.16554 41.823893 2024-Nov-30 02:40 A 05 45 15.71 +13 52 46.2 310.177824 36.654137 n.a. n.a. 0.996718384013 -0.1971330 0.01115333114763 0.2839773 159.4121 /L 20.3625 146.8/ 1.2566 n.a. n.a. 2.1758642 237.42687 44.067412 2024-Nov-30 02:50 A 05 45 14.48 +13 52 34.3 308.133902 34.866367 n.a. n.a. 0.996717593422 -0.1971034 0.01115449803393 0.2978331 159.4215 /L 20.3532 146.9/ 1.2404 n.a. n.a. 2.1145999 235.54233 46.247042 2024-Nov-30 03:00 Am 05 45 13.32 +13 52 22.2 306.200999 33.029289 n.a. n.a. 0.996716802949 -0.1970737 0.01115571943509 0.3111581 159.4306 /L 20.3442 147.0/ 1.2245 n.a. n.a. 2.0515199 233.49492 48.358236 2024-Nov-30 03:10 Nm 05 45 12.23 +13 52 09.9 304.370949 31.147616 n.a. n.a. 0.996716012596 -0.1970441 0.01115699317019 0.3239266 159.4394 /L 20.3355 147.0/ 1.2090 n.a. n.a. 1.9871793 231.26585 50.395648 2024-Nov-30 03:20 Nm 05 45 11.20 +13 51 57.3 302.635923 29.225594 n.a. n.a. 0.996715222361 -0.1970144 0.01115831695825 0.3361142 159.4479 /L 20.3270 147.1/ 1.1940 n.a. n.a. 1.9222028 228.83465 52.352995 2024-Nov-30 03:30 Nm 05 45 10.24 +13 51 44.5 300.988491 27.267034 n.a. n.a. 0.996714432245 -0.1969848 0.01115968842264 0.3476978 159.4561 /L 20.3188 147.2/ 1.1793 n.a. n.a. 1.8572940 226.17942 54.222913 2024-Nov-30 03:40 Cm 05 45 09.36 +13 51 31.5 299.421657 25.275361 n.a. n.a. 0.996713642248 -0.1969552 0.01116110509580 0.3586551 159.4641 /L 20.3110 147.3/ 1.1650 n.a. n.a. 1.7932432 223.27738 55.996821 2024-Nov-30 03:50 Cm 05 45 08.56 +13 51 18.3 297.928872 23.253650 n.a. n.a. 0.996712852370 -0.1969255 0.01116256442408 0.3689654 159.4717 /L 20.3034 147.4/ 1.1511 n.a. n.a. 1.7309353 220.10584 57.664809 >..... Daylight Cut-off Requested .....< >..... Elevation Cut-off Requested .....< 2024-Nov-30 18:30 A 05 47 16.04 +13 40 09.3 74.767021 0.715401 n.a. n.a. 0.996643806834 -0.1943315 0.01118670801485 -0.3901761 159.4665 /L 20.3080 151.9/ 0.4344 n.a. n.a. 0.2263447 72.333168 -85.51463 2024-Nov-30 18:40 A 05 47 16.14 +13 40 10.0 73.757972 2.932095 n.a. n.a. 0.996643027476 -0.1943022 0.01118514800885 -0.3876281 159.4725 /L 20.3021 152.0/ 0.4242 n.a. n.a. 0.1013603 50.638080 -87.97518 2024-Nov-30 18:50 A 05 47 16.15 +13 40 10.6 72.721814 5.137638 n.a. n.a. 0.996642248236 -0.1942729 0.01118359979728 -0.3842953 159.4787 /L 20.2960 152.1/ 0.4141 n.a. n.a. 0.0823609 315.22123 -88.34046 2024-Nov-30 19:00 05 47 16.06 +13 40 11.1 71.655389 7.330972 n.a. n.a. 0.996641469114 -0.1942436 0.01118206651588 -0.3801839 159.4853 /L 20.2895 152.2/ 0.4040 n.a. n.a. 0.1998861 284.85203 -85.93510 2024-Nov-30 19:10 05 47 15.88 +13 40 11.6 70.555348 9.510938 n.a. n.a. 0.996640690109 -0.1942143 0.01118055127325 -0.3753012 159.4923 /L 20.2826 152.3/ 0.3940 n.a. n.a. 0.3297244 277.42618 -83.22869 2024-Nov-30 19:20 05 47 15.61 +13 40 12.0 69.418128 11.676264 n.a. n.a. 0.996639911221 -0.1941850 0.01117905714483 -0.3696564 159.4995 /L 20.2755 152.4/ 0.3840 n.a. n.a. 0.4601646 274.06507 -80.45144 2024-Nov-30 19:30 05 47 15.25 +13 40 12.2 68.239923 13.825552 n.a. n.a. 0.996639132451 -0.1941557 0.01117758716698 -0.3632598 159.5071 /L 20.2680 152.5/ 0.3741 n.a. n.a. 0.5894813 272.06750 -77.63355 2024-Nov-30 19:40 05 47 14.80 +13 40 12.4 67.016650 15.957258 n.a. n.a. 0.996638353799 -0.1941264 0.01117614433107 -0.3561235 159.5150 /L 20.2602 152.6/ 0.3643 n.a. n.a. 0.7170302 270.68523 -74.78375 2024-Nov-30 19:50 05 47 14.27 +13 40 12.4 65.743921 18.069678 n.a. n.a. 0.996637575264 -0.1940971 0.01117473157771 -0.3482608 159.5232 /L 20.2522 152.7/ 0.3546 n.a. n.a. 0.8424209 269.63066 -71.90592 2024-Nov-30 20:00 05 47 13.65 +13 40 12.2 64.417012 20.160924 n.a. n.a. 0.996636796846 -0.1940678 0.01117335179101 -0.3396864 159.5316 /L 20.2438 152.8/ 0.3450 n.a. n.a. 0.9653499 268.76991 -69.00240 2024-Nov-30 20:10 05 47 12.95 +13 40 11.9 63.030832 22.228901 n.a. n.a. 0.996636018546 -0.1940385 0.01117200779303 -0.3304166 159.5404 /L 20.2352 152.9/ 0.3355 n.a. n.a. 1.0855528 268.03219 -66.07504 2024-Nov-30 20:20 05 47 12.16 +13 40 11.4 61.579892 24.271282 n.a. n.a. 0.996635240363 -0.1940092 0.01117070233819 -0.3204690 159.5494 /L 20.2263 153.1/ 0.3261 n.a. n.a. 1.2027864 267.37648 -63.12549 2024-Nov-30 20:30 05 47 11.30 +13 40 10.7 60.058278 26.285477 n.a. n.a. 0.996634462298 -0.1939800 0.01116943810795 -0.3098622 159.5587 /L 20.2171 153.2/ 0.3169 n.a. n.a. 1.3168220 266.77728 -60.15541 2024-Nov-30 20:40 05 47 10.36 +13 40 09.9 58.459635 28.268601 n.a. n.a. 0.996633684351 -0.1939507 0.01116821770559 -0.2986166 159.5683 /L 20.2077 153.3/ 0.3078 n.a. n.a. 1.4274417 266.21783 -57.16654 2024-Nov-30 20:50 05 47 09.34 +13 40 08.8 56.777147 30.217442 n.a. n.a. 0.996632906521 -0.1939214 0.01116704365107 -0.2867534 159.5781 /L 20.1980 153.4/ 0.2989 n.a. n.a. 1.5344376 265.68659 -54.16068 2024-Nov-30 21:00 05 47 08.26 +13 40 07.5 55.003541 32.128418 n.a. n.a. 0.996632128808 -0.1938922 0.01116591837608 -0.2742953 159.5881 /L 20.1881 153.5/ 0.2901 n.a. n.a. 1.6376110 265.17529 -51.13977 2024-Nov-30 21:10 05 47 07.11 +13 40 05.9 53.131101 33.997536 n.a. n.a. 0.996631351212 -0.1938629 0.01116484421935 -0.2612661 159.5983 /L 20.1780 153.6/ 0.2815 n.a. n.a. 1.7367721 264.67779 -48.10585 2024-Nov-30 21:20 05 47 05.89 +13 40 04.2 51.151717 35.820351 n.a. n.a. 0.996630573734 -0.1938336 0.01116382342194 -0.2476906 159.6088 /L 20.1676 153.7/ 0.2731 n.a. n.a. 1.8317402 264.18933 -45.06107 2024-Nov-30 21:30 05 47 04.61 +13 40 02.1 49.056958 37.591924 n.a. n.a. 0.996629796374 -0.1938044 0.01116285812290 -0.2335949 159.6194 /L 20.1571 153.8/ 0.2649 n.a. n.a. 1.9223439 263.70618 -42.00769 2024-Nov-30 21:40 05 47 03.27 +13 39 59.8 46.838198 39.306777 n.a. n.a. 0.996629019130 -0.1937751 0.01116195035506 -0.2190058 159.6303 /L 20.1464 153.9/ 0.2568 n.a. n.a. 2.0084214 263.22523 -38.94806 2024-Nov-30 21:50 05 47 01.87 +13 39 57.3 44.486798 40.958858 n.a. n.a. 0.996628242004 -0.1937459 0.01116110204097 -0.2039515 159.6413 /L 20.1355 154.0/ 0.2490 n.a. n.a. 2.0898210 262.74390 -35.88459 2024-Nov-30 22:00 05 47 00.43 +13 39 54.5 41.994366 42.541514 n.a. n.a. 0.996627464996 -0.1937166 0.01116031498916 -0.1884608 159.6524 /L 20.1245 154.1/ 0.2414 n.a. n.a. 2.1664010 262.25992 -32.81976 2024-Nov-30 22:10 05 46 58.93 +13 39 51.3 39.353097 44.047477 n.a. n.a. 0.996626688104 -0.1936874 0.01115959089050 -0.1725634 159.6637 /L 20.1134 154.3/ 0.2340 n.a. n.a. 2.2380304 261.77126 -29.75610 2024-Nov-30 22:20 05 46 57.39 +13 39 47.9 36.556223 45.468879 n.a. n.a. 0.996625911330 -0.1936582 0.01115893131490 -0.1562900 159.6751 /L 20.1021 154.4/ 0.2268 n.a. n.a. 2.3045892 261.27604 -26.69614 2024-Nov-30 22:30 05 46 55.81 +13 39 44.2 33.598559 46.797290 n.a. n.a. 0.996625134674 -0.1936290 0.01115833770818 -0.1396717 159.6867 /L 20.0907 154.5/ 0.2198 n.a. n.a. 2.3659688 260.77251 -23.64242 2024-Nov-30 22:40 05 46 54.19 +13 39 40.2 30.477149 48.023802 n.a. n.a. 0.996624358134 -0.1935997 0.01115781138921 -0.1227407 159.6983 /L 20.0792 154.6/ 0.2131 n.a. n.a. 2.4220722 260.25896 -20.59747 2024-Nov-30 22:50 05 46 52.53 +13 39 35.9 27.191998 49.139168 n.a. n.a. 0.996623581712 -0.1935705 0.01115735354730 -0.1055294 159.7100 /L 20.0676 154.7/ 0.2066 n.a. n.a. 2.4728145 259.73369 -17.56377 2024-Nov-30 23:00 05 46 50.85 +13 39 31.3 23.746812 50.133993 n.a. n.a. 0.996622805407 -0.1935413 0.01115696523985 -0.0880712 159.7218 /L 20.0560 154.8/ 0.2003 n.a. n.a. 2.5181232 259.19500 -14.54375 2024-Nov-30 23:10 05 46 49.14 +13 39 26.4 20.149704 50.998996 n.a. n.a. 0.996622029219 -0.1935121 0.01115664739019 -0.0703996 159.7336 /L 20.0443 154.9/ 0.1943 n.a. n.a. 2.5579385 258.64115 -11.53978 2024-Nov-30 23:20 05 46 47.41 +13 39 21.1 16.413731 51.725324 n.a. n.a. 0.996621253148 -0.1934829 0.01115640078581 -0.0525487 159.7455 /L 20.0325 155.0/ 0.1885 n.a. n.a. 2.5922138 258.07032 -8.554142 2024-Nov-30 23:30 05 46 45.67 +13 39 15.5 12.557170 52.304918 n.a. n.a. 0.996620477195 -0.1934537 0.01115622607675 -0.0345530 159.7573 /L 20.0208 155.1/ 0.1830 n.a. n.a. 2.6209159 257.48061 -5.589043 2024-Nov-30 23:40 05 46 43.91 +13 39 09.6 8.603393 52.730899 n.a. n.a. 0.996619701358 -0.1934245 0.01115612377433 -0.0164472 159.7692 /L 20.0090 155.2/ 0.1777 n.a. n.a. 2.6440256 256.86999 -2.646578 2024-Nov-30 23:50 05 46 42.14 +13 39 03.4 4.580284 52.997938 n.a. n.a. 0.996618925639 -0.1933953 0.01115609425011 0.0017338 159.7811 /L 19.9973 155.3/ 0.1726 n.a. n.a. 2.6615377 256.23628 0.2712513 2024-Dec-01 00:00 05 46 40.36 +13 38 56.8 0.519166 53.102567 n.a. n.a. 0.996618150037 -0.1933661 0.01115613773515 0.0199548 159.7929 /L 19.9856 155.4/ 0.1679 n.a. n.a. 2.6734613 255.57712 3.1625454 $$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/hrzn_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************