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 Mon Dec 9 18:32:10 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: Swan Reach Imaging, Glenalta ******************************************************************************* 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 : 139.5701, -34.5440227, .056888 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 139.5701,5259.32258,-3596.34777 {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.241209.p250307 EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-DEC-09. PREDICTS-> 2025-MAR-06 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 .....< 2024-Nov-30 10:30 N 05 46 50.83 +13 47 50.5 73.129192 0.038773 n.a. n.a. 0.996681354527 -0.1957430 0.01118291067311 -0.3447257 159.3174 /L 20.4557 148.7/ 0.8793 n.a. n.a. 0.1252950 96.807007 -87.18720 2024-Nov-30 10:40 N 05 46 50.87 +13 47 50.3 71.696564 2.006976 n.a. n.a. 0.996680569508 -0.1957136 0.01118153412673 -0.3416066 159.3234 /L 20.4497 148.8/ 0.8638 n.a. n.a. 0.0204966 173.65239 -89.53536 2024-Nov-30 10:50 A 05 46 50.83 +13 47 50.1 70.239797 3.959109 n.a. n.a. 0.996679784608 -0.1956841 0.01118017148866 -0.3377911 159.3298 /L 20.4434 148.9/ 0.8484 n.a. n.a. 0.1218333 257.11908 -87.20943 2024-Nov-30 11:00 A 05 46 50.71 +13 47 49.8 68.755591 5.893602 n.a. n.a. 0.996678999826 -0.1956546 0.01117882553862 -0.3332860 159.3365 /L 20.4368 149.0/ 0.8329 n.a. n.a. 0.2410408 261.60171 -84.41838 2024-Nov-30 11:10 A 05 46 50.50 +13 47 49.4 67.240581 7.808781 n.a. n.a. 0.996678215162 -0.1956251 0.01117749902546 -0.3280999 159.3434 /L 20.4300 149.1/ 0.8175 n.a. n.a. 0.3593343 262.88759 -81.58290 2024-Nov-30 11:20 A 05 46 50.22 +13 47 48.9 65.691328 9.702862 n.a. n.a. 0.996677430616 -0.1955956 0.01117619466195 -0.3222423 159.3507 /L 20.4228 149.2/ 0.8020 n.a. n.a. 0.4760675 263.36550 -78.71311 2024-Nov-30 11:30 05 46 49.85 +13 47 48.3 64.104311 11.573933 n.a. n.a. 0.996676646189 -0.1955662 0.01117491511942 -0.3157242 159.3582 /L 20.4154 149.3/ 0.7867 n.a. n.a. 0.5909404 263.51734 -75.81157 2024-Nov-30 11:40 05 46 49.41 +13 47 47.5 62.475922 13.419944 n.a. n.a. 0.996675861880 -0.1955367 0.01117366302266 -0.3085579 159.3660 /L 20.4077 149.4/ 0.7713 n.a. n.a. 0.7037142 263.50370 -72.87966 2024-Nov-30 11:50 05 46 48.90 +13 47 46.6 60.802464 15.238694 n.a. n.a. 0.996675077689 -0.1955072 0.01117244094480 -0.3007569 159.3740 /L 20.3998 149.5/ 0.7561 n.a. n.a. 0.8141707 263.39316 -69.91863 2024-Nov-30 12:00 05 46 48.30 +13 47 45.6 59.080154 17.027817 n.a. n.a. 0.996674293616 -0.1954778 0.01117125140233 -0.2923359 159.3823 /L 20.3916 149.6/ 0.7409 n.a. n.a. 0.9221026 263.21978 -66.92977 2024-Nov-30 12:10 05 46 47.64 +13 47 44.4 57.305131 18.784767 n.a. n.a. 0.996673509661 -0.1954483 0.01117009685018 -0.2833108 159.3909 /L 20.3831 149.7/ 0.7258 n.a. n.a. 1.0273103 263.00228 -63.91454 2024-Nov-30 12:20 05 46 46.90 +13 47 43.0 55.473476 20.506808 n.a. n.a. 0.996672725824 -0.1954189 0.01116897967699 -0.2736989 159.3997 /L 20.3745 149.8/ 0.7108 n.a. n.a. 1.1296010 262.75169 -60.87456 2024-Nov-30 12:30 05 46 46.10 +13 47 41.5 53.581229 22.190998 n.a. n.a. 0.996671942106 -0.1953894 0.01116790220035 -0.2635183 159.4087 /L 20.3656 149.9/ 0.6959 n.a. n.a. 1.2287887 262.47482 -57.81167 2024-Nov-30 12:40 05 46 45.23 +13 47 39.8 51.624431 23.834177 n.a. n.a. 0.996671158506 -0.1953600 0.01116686666241 -0.2527884 159.4180 /L 20.3564 150.0/ 0.6812 n.a. n.a. 1.3246942 262.17603 -54.72789 2024-Nov-30 12:50 05 46 44.30 +13 47 37.8 49.599161 25.432958 n.a. n.a. 0.996670375024 -0.1953306 0.01116587522536 -0.2415298 159.4274 /L 20.3471 150.1/ 0.6665 n.a. n.a. 1.4171452 261.85814 -51.62546 2024-Nov-30 13:00 05 46 43.31 +13 47 35.7 47.501603 26.983719 n.a. n.a. 0.996669591659 -0.1953011 0.01116492996730 -0.2297638 159.4370 /L 20.3376 150.2/ 0.6520 n.a. n.a. 1.5059770 261.52296 -48.50680 2024-Nov-30 13:10 05 46 42.26 +13 47 33.3 45.328113 28.482598 n.a. n.a. 0.996668808413 -0.1952717 0.01116403287811 -0.2175130 159.4469 /L 20.3279 150.3/ 0.6376 n.a. n.a. 1.5910325 261.17164 -45.37450 2024-Nov-30 13:20 05 46 41.15 +13 47 30.7 43.075312 29.925493 n.a. n.a. 0.996668025285 -0.1952423 0.01116318585556 -0.2048008 159.4569 /L 20.3180 150.5/ 0.6234 n.a. n.a. 1.6721627 260.80482 -42.23133 2024-Nov-30 13:30 05 46 39.99 +13 47 27.9 40.740196 31.308070 n.a. n.a. 0.996667242276 -0.1952128 0.01116239070158 -0.1916516 159.4670 /L 20.3079 150.6/ 0.6094 n.a. n.a. 1.7492271 260.42280 -39.08019 2024-Nov-30 13:40 05 46 38.79 +13 47 24.8 38.320261 32.625774 n.a. n.a. 0.996666459384 -0.1951834 0.01116164911871 -0.1780905 159.4774 /L 20.2978 150.7/ 0.5955 n.a. n.a. 1.8220941 260.02558 -35.92409 2024-Nov-30 13:50 05 46 37.53 +13 47 21.5 35.813643 33.873854 n.a. n.a. 0.996665676610 -0.1951540 0.01116096270677 -0.1641436 159.4878 /L 20.2874 150.8/ 0.5819 n.a. n.a. 1.8906411 259.61295 -32.76614 2024-Nov-30 14:00 05 46 36.24 +13 47 17.9 33.219282 35.047396 n.a. n.a. 0.996664893954 -0.1951246 0.01116033295967 -0.1498377 159.4984 /L 20.2770 150.9/ 0.5684 n.a. n.a. 1.9547552 259.18452 -29.60950 2024-Nov-30 14:10 05 46 34.90 +13 47 14.0 30.537081 36.141372 n.a. n.a. 0.996664111416 -0.1950952 0.01115976126250 -0.1352002 159.5091 /L 20.2664 151.0/ 0.5551 n.a. n.a. 2.0143337 258.73970 -26.45736 2024-Nov-30 14:20 05 46 33.53 +13 47 09.9 27.768082 37.150696 n.a. n.a. 0.996663328996 -0.1950658 0.01115924888879 -0.1202593 159.5199 /L 20.2557 151.1/ 0.5420 n.a. n.a. 2.0692836 258.27778 -23.31291 2024-Nov-30 14:30 05 46 32.12 +13 47 05.5 24.914621 38.070301 n.a. n.a. 0.996662546695 -0.1950364 0.01115879699797 -0.1050438 159.5307 /L 20.2450 151.2/ 0.5292 n.a. n.a. 2.1195230 257.79787 -20.17934 2024-Nov-30 14:40 05 46 30.68 +13 47 00.8 21.980474 38.895224 n.a. n.a. 0.996661764511 -0.1950069 0.01115840663309 -0.0895828 159.5417 /L 20.2342 151.3/ 0.5165 n.a. n.a. 2.1649808 257.29895 -17.05973 2024-Nov-30 14:50 05 46 29.22 +13 46 55.9 18.970959 39.620710 n.a. n.a. 0.996660982445 -0.1949775 0.01115807871874 -0.0739063 159.5527 /L 20.2233 151.4/ 0.5041 n.a. n.a. 2.2055971 256.77986 -13.95713 2024-Nov-30 15:00 05 46 27.74 +13 46 50.7 15.892988 40.242318 n.a. n.a. 0.996660200497 -0.1949481 0.01115781405925 -0.0580443 159.5637 /L 20.2124 151.5/ 0.4919 n.a. n.a. 2.2413240 256.23927 -10.87446 2024-Nov-30 15:10 05 46 26.24 +13 46 45.1 12.755063 40.756036 n.a. n.a. 0.996659418667 -0.1949187 0.01115761333707 -0.0420275 159.5748 /L 20.2014 151.7/ 0.4800 n.a. n.a. 2.2721252 255.67569 -7.814522 2024-Nov-30 15:20 05 46 24.72 +13 46 39.3 9.567181 41.158396 n.a. n.a. 0.996658636956 -0.1948893 0.01115747711142 -0.0258867 159.5859 /L 20.1904 151.8/ 0.4683 n.a. n.a. 2.2979772 255.08746 -4.779988 2024-Nov-30 15:30 05 46 23.19 +13 46 33.2 6.340673 41.446582 n.a. n.a. 0.996657855362 -0.1948599 0.01115740581720 -0.0096530 159.5970 /L 20.1795 151.9/ 0.4569 n.a. n.a. 2.3188690 254.47272 -1.773381 2024-Nov-30 15:40 05 46 21.66 +13 46 26.8 3.087945 41.618518 n.a. n.a. 0.996657073886 -0.1948305 0.01115739976410 0.0066422 159.6081 /L 20.1685 152.0/ 0.4457 n.a. n.a. 2.3348029 253.82940 1.2029252 2024-Nov-30 15:50 t 05 46 20.12 +13 46 20.1 359.822163 41.672943 n.a. n.a. 0.996656292528 -0.1948012 0.01115745913602 0.0229675 159.6191 /L 20.1576 152.1/ 0.4347 n.a. n.a. 2.3457947 253.15519 4.1467076 2024-Nov-30 16:00 05 46 18.58 +13 46 13.1 356.556877 41.609454 n.a. n.a. 0.996655511287 -0.1947718 0.01115758399065 0.0392915 159.6301 /L 20.1467 152.2/ 0.4240 n.a. n.a. 2.3518743 252.44753 7.0558888 2024-Nov-30 16:10 05 46 17.04 +13 46 05.8 353.305622 41.428522 n.a. n.a. 0.996654730165 -0.1947424 0.01115777425940 0.0555826 159.6411 /L 20.1358 152.3/ 0.4136 n.a. n.a. 2.3530862 251.70356 9.9285280 2024-Nov-30 16:20 05 46 15.52 +13 45 58.2 350.081517 41.131474 n.a. n.a. 0.996653949161 -0.1947130 0.01115802974752 0.0718095 159.6520 /L 20.1250 152.4/ 0.4035 n.a. n.a. 2.3494900 250.92008 12.762807 2024-Nov-30 16:30 05 46 14.00 +13 45 50.3 346.896896 40.720447 n.a. n.a. 0.996653168274 -0.1946836 0.01115835013448 0.0879408 159.6628 /L 20.1143 152.5/ 0.3936 n.a. n.a. 2.3411610 250.09355 15.557014 2024-Nov-30 16:40 05 46 12.50 +13 45 42.1 343.762993 40.198313 n.a. n.a. 0.996652387505 -0.1946543 0.01115873497461 0.1039455 159.6735 /L 20.1037 152.6/ 0.3840 n.a. n.a. 2.3281912 249.21999 18.309516 2024-Nov-30 16:50 05 46 11.01 +13 45 33.7 340.689693 39.568586 n.a. n.a. 0.996651606855 -0.1946249 0.01115918369795 0.1197926 159.6841 /L 20.0932 152.7/ 0.3746 n.a. n.a. 2.3106897 248.29494 21.018740 2024-Nov-30 17:00 05 46 09.55 +13 45 24.9 337.685376 38.835315 n.a. n.a. 0.996650826321 -0.1945956 0.01115969561146 0.1354517 159.6946 /L 20.0828 152.8/ 0.3655 n.a. n.a. 2.2887842 247.31342 23.683133 2024-Nov-30 17:10 05 46 08.12 +13 45 15.9 334.756831 38.002972 n.a. n.a. 0.996650045906 -0.1945662 0.01116026990026 0.1508926 159.7050 /L 20.0726 152.9/ 0.3567 n.a. n.a. 2.2626217 246.26984 26.301135 2024-Nov-30 17:20 05 46 06.72 +13 45 06.6 331.909250 37.076332 n.a. n.a. 0.996649265609 -0.1945368 0.01116090562935 0.1660855 159.7152 /L 20.0625 153.0/ 0.3482 n.a. n.a. 2.2323703 245.15791 28.871134 2024-Nov-30 17:30 05 46 05.34 +13 44 57.1 329.146292 36.060370 n.a. n.a. 0.996648485429 -0.1945075 0.01116160174545 0.1810012 159.7252 /L 20.0525 153.1/ 0.3399 n.a. n.a. 2.1982206 243.97057 31.391423 2024-Nov-30 17:40 A 05 46 04.01 +13 44 47.2 326.470188 34.960159 n.a. n.a. 0.996647705367 -0.1944782 0.01116235707898 0.1956110 159.7351 /L 20.0427 153.2/ 0.3319 n.a. n.a. 2.1603877 242.69987 33.860147 2024-Nov-30 17:50 A 05 46 02.71 +13 44 37.1 323.881881 33.780783 n.a. n.a. 0.996646925422 -0.1944488 0.01116317034649 0.2098867 159.7448 /L 20.0331 153.2/ 0.3241 n.a. n.a. 2.1191134 241.33689 36.275249 2024-Nov-30 18:00 A 05 46 01.46 +13 44 26.8 321.381193 32.527265 n.a. n.a. 0.996646145596 -0.1944195 0.01116404015313 0.2238011 159.7543 /L 20.0237 153.3/ 0.3167 n.a. n.a. 2.0746694 239.87158 38.634403 2024-Nov-30 18:10 A 05 46 00.25 +13 44 16.2 318.966993 31.204509 n.a. n.a. 0.996645365887 -0.1943902 0.01116496499542 0.2373272 159.7636 /L 20.0145 153.4/ 0.3094 n.a. n.a. 2.0273599 238.29266 40.934944 2024-Nov-30 18:20 N 05 45 59.10 +13 44 05.4 316.637360 29.817253 n.a. n.a. 0.996644586295 -0.1943608 0.01116594326418 0.2504392 159.7727 /L 20.0055 153.5/ 0.3025 n.a. n.a. 1.9775262 236.58751 43.173782 2024-Nov-30 18:30 N 05 45 57.99 +13 43 54.4 314.389743 28.370035 n.a. n.a. 0.996643806821 -0.1943315 0.01116697324774 0.2631119 159.7815 /L 19.9967 153.6/ 0.2958 n.a. n.a. 1.9255504 234.74205 45.347312 2024-Nov-30 18:40 N 05 45 56.94 +13 43 43.1 312.221101 26.867174 n.a. n.a. 0.996643027465 -0.1943022 0.01116805313528 0.2753210 159.7902 /L 19.9882 153.7/ 0.2894 n.a. n.a. 1.8718614 232.74068 47.451312 2024-Nov-30 18:50 Nm 05 45 55.95 +13 43 31.6 310.128028 25.312756 n.a. n.a. 0.996642248227 -0.1942729 0.01116918102040 0.2870432 159.7985 /L 19.9798 153.8/ 0.2832 n.a. n.a. 1.8169401 230.56627 49.480827 2024-Nov-30 19:00 Cm 05 45 55.02 +13 43 20.0 308.106862 23.710623 n.a. n.a. 0.996641469106 -0.1942436 0.01117035490486 0.2982561 159.8067 /L 19.9718 153.8/ 0.2772 n.a. n.a. 1.7613261 228.20027 51.430051 2024-Nov-30 19:10 Cm 05 45 54.16 +13 43 08.1 306.153770 22.064382 n.a. n.a. 0.996640690103 -0.1942143 0.01117157270250 0.3089381 159.8145 /L 19.9640 153.9/ 0.2715 n.a. n.a. 1.7056244 225.62296 53.292203 2024-Nov-30 19:20 Cm 05 45 53.36 +13 42 56.0 304.264823 20.377403 n.a. n.a. 0.996639911217 -0.1941850 0.01117283224330 0.3190690 159.8221 /L 19.9564 154.0/ 0.2661 n.a. n.a. 1.6505118 222.81396 55.059412 >..... Daylight 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/hrzn_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ***************************************************************************************************************************************************************************************************************************************************