These images have been extracted from the full frame fits images. They are processed to center Neptune in the frame, and to transform the image so that north is up and west to the right, as Neptune would appear in the sky. They are shown in approximately consistent gray scale to enhance the visibility of Triton. Other objects are stars (and one distant galaxy). The nightly motion of Neptune may be followed in the original full frame images which have a field of view of 0.6 degrees. These images are 512x512 pixels with a field of view of approximately 274.5 arcseconds at 0.5361 arcseconds/pixel. Neptune was approximately 28.98 AU from us at the time of the images. One pixel corresponds to 7.532x10^-5 AU or 11,270 km at this distance. (1 AU is 149.6 x 10^6 km.) Use Sky and Telescope's Triton Tracker to follow the satellite's nightly progression: http://www.skyandtelescope.com/observing/objects/javascript/triton_tracker/index.html# ======================================================================================= Target: Neptune is at center, Triton in orbit Dates: Various Telescope: CDK20n Camera: Apogee Filters: Sloan z' or Sloan i' Exposure time: 100 seconds Observer: J. Kielkopf Processing: J. Kielkopf -- Alsvid to dark subtract and flat field AstroImageJ to scale, recenter, crop, tranform N up and W right, export to png Linear scaling on all images Triton orbits with a period of 5.877 days and orbital inclination of 156.9 degrees, that is the plane of its orbit is 156.9 degrees to the plane of its equator, and it orbits retrograde inclined 23.1 degrees (180-156.9 = 23.1). Neptune's axis is inclined 1.77 degrees to the ecliptic. Dates and start times for the images are 2012-08-24 4:17:02 neptune_i_utc_20120824.png 2012-08-25 5:32:01 neptune_z_utc_20120825.png 2012-08-26 5:23:08 neptune_z_utc_20120826.png 2012-08-29 5:01:35 neptune_z_utc_20120829.png 2012-09-14 3:45:16 neptune_z_utc_20120914.png ======================================================================================== On 2012-08-25 Neptune was 28.984 AU from Earth and appeared at V Mag = 7.83 . Calucation from http://www.imcce.fr/en/ephemerides/formulaire/form_ephepos.php gives: ####################################################################################### EPHEMERIS OF SOLAR SYSTEM BODIES ####################################################################################### Planet 8 Neptune Planetary theory INPOP10 Astrometric J2000 coordinates Frame center: geocenter Relativistic perturbations, coordinate system 0 Equatorial coordinates (R.A, Dec.) ####################################################################################### Date UTC R.A Dec. Distance V.Mag Phase Elong. muRAcosDE muDE Dist_dot h m s h m s o ' " au. o o "/s "/s km/s 8 25 2012 5 32 1.00 22 15 7.44024 -11 30 24.9922 28.984184693 7.83 0.03 179.05 -0.1064E-02 -0.4142E-03 0.69822 8 26 2012 5 32 1.00 22 15 1.18460 -11 31 0.7539 28.984735705 7.83 0.06 178.18 -0.1064E-02 -0.4136E-03 1.20977 8 27 2012 5 32 1.00 22 14 54.93292 -11 31 36.4593 28.985581959 7.83 0.09 177.23 -0.1063E-02 -0.4129E-03 1.72060 8 28 2012 5 32 1.00 22 14 48.68750 -11 32 12.0956 28.986723016 7.83 0.13 176.26 -0.1062E-02 -0.4120E-03 2.23065 8 29 2012 5 32 1.00 22 14 42.45060 -11 32 47.6503 28.988158426 7.83 0.16 175.27 -0.1060E-02 -0.4110E-03 2.73991 8 30 2012 5 32 1.00 22 14 36.22447 -11 33 23.1112 28.989887734 7.83 0.19 174.29 -0.1058E-02 -0.4098E-03 3.24840 8 31 2012 5 32 1.00 22 14 30.01133 -11 33 58.4658 28.991910496 7.83 0.23 173.30 -0.1056E-02 -0.4085E-03 3.75612 9 1 2012 5 32 1.00 22 14 23.81340 -11 34 33.7018 28.994226275 7.83 0.26 172.31 -0.1053E-02 -0.4071E-03 4.26309 9 2 2012 5 32 1.00 22 14 17.63290 -11 35 8.8067 28.996834631 7.83 0.29 171.32 -0.1050E-02 -0.4055E-03 4.76929 9 3 2012 5 32 1.00 22 14 11.47209 -11 35 43.7680 28.999735106 7.83 0.32 170.32 -0.1046E-02 -0.4038E-03 5.27466 9 14 2012 5 32 1.00 22 13 5.66366 -11 41 55.1575 29.050729061 7.83 0.68 159.36 -0.9804E-03 -0.3747E-03 10.74464 ####################################################################################### EPHEMERIS OF SOLAR SYSTEM BODIES ####################################################################################### Satellite 801 Triton Planetary theory INPOP10 Astrometric J2000 coordinates Frame center: geocenter Relativistic perturbations, coordinate system 0 Equatorial coordinates (R.A, Dec.) ####################################################################################### Date UTC R.A Dec. Distance V.Mag Phase Elong. muRAcosDE muDE Dist_dot h m s h m s o ' " au. o o "/s "/s km/s 8 25 2012 5 32 1.00 22 15 7.54618 -11 30 10.7635 28.982928388 13.46 0.03 179.06 -0.8852E-03 -0.3720E-03 2.76645 8 26 2012 5 32 1.00 22 15 2.09989 -11 30 50.9205 28.985110437 13.46 0.06 178.19 -0.9945E-03 -0.5477E-03 4.24177 8 27 2012 5 32 1.00 22 14 55.70781 -11 31 41.2262 28.987198559 13.46 0.09 177.23 -0.1176E-02 -0.5840E-03 2.57217 8 28 2012 5 32 1.00 22 14 48.51753 -11 32 26.5102 28.987904844 13.46 0.13 176.25 -0.1239E-02 -0.4426E-03 0.01972 8 29 2012 5 32 1.00 22 14 41.51171 -11 32 56.7469 28.987680245 13.46 0.16 175.27 -0.1118E-02 -0.2693E-03 -0.23994 8 30 2012 5 32 1.00 22 14 35.49101 -11 33 17.4476 28.988246118 13.46 0.19 174.29 -0.9364E-03 -0.2430E-03 2.59009 8 31 2012 5 32 1.00 22 14 30.24482 -11 33 43.9262 28.990808333 13.46 0.23 173.30 -0.8801E-03 -0.3898E-03 6.10108 9 1 2012 5 32 1.00 22 14 24.77180 -11 34 25.3814 28.994806279 13.46 0.26 172.31 -0.1006E-02 -0.5558E-03 7.17836 9 2 2012 5 32 1.00 22 14 18.32166 -11 35 15.3382 28.998494786 13.46 0.29 171.32 -0.1180E-02 -0.5672E-03 5.23194 9 3 2012 5 32 1.00 22 14 11.17618 -11 35 58.3658 29.000753685 13.46 0.32 170.32 -0.1218E-02 -0.4107E-03 2.80593 9 14 2012 5 32 1.00 22 13 6.14551 -11 42 4.8292 29.052394701 13.46 0.68 159.36 -0.1138E-02 -0.5094E-03 10.41587 ####################################################################################### EPHEMERIS OF SOLAR SYSTEM BODIES ####################################################################################### Satellite 802 Nereid Planetary theory INPOP10 Astrometric J2000 coordinates Frame center: geocenter Relativistic perturbations, coordinate system 0 Equatorial coordinates (R.A, Dec.) ####################################################################################### Date UTC R.A Dec. Distance V.Mag Phase Elong. muRAcosDE muDE Dist_dot h m s h m s o ' " au. o o "/s "/s km/s 8 25 2012 5 32 1.00 22 15 34.77724 -11 27 12.4743 28.974081743 18.69 0.03 179.15 -0.1062E-02 -0.4142E-03 0.20171 8 26 2012 5 32 1.00 22 15 28.53574 -11 27 48.2454 28.974346386 18.69 0.06 178.30 -0.1062E-02 -0.4138E-03 0.71450 8 27 2012 5 32 1.00 22 15 22.29597 -11 28 23.9764 28.974906801 18.69 0.09 177.35 -0.1061E-02 -0.4133E-03 1.22596 8 28 2012 5 32 1.00 22 15 16.06029 -11 28 59.6513 28.975762314 18.69 0.12 176.38 -0.1060E-02 -0.4125E-03 1.73651 8 29 2012 5 32 1.00 22 15 9.83114 -11 29 35.2555 28.976912596 18.69 0.16 175.40 -0.1059E-02 -0.4116E-03 2.24680 8 30 2012 5 32 1.00 22 15 3.61096 -11 30 10.7778 28.978357584 18.69 0.19 174.41 -0.1057E-02 -0.4106E-03 2.75702 8 31 2012 5 32 1.00 22 14 57.40192 -11 30 46.2089 28.980097114 18.69 0.22 173.42 -0.1055E-02 -0.4095E-03 3.26666 9 1 2012 5 32 1.00 22 14 51.20604 -11 31 21.5384 28.982130659 18.69 0.25 172.43 -0.1053E-02 -0.4083E-03 3.77508 9 2 2012 5 32 1.00 22 14 45.02540 -11 31 56.7524 28.984457444 18.70 0.29 171.44 -0.1050E-02 -0.4068E-03 4.28216 9 3 2012 5 32 1.00 22 14 38.86230 -11 32 31.8349 28.987076807 18.70 0.32 170.45 -0.1047E-02 -0.4052E-03 4.78837 9 14 2012 5 32 1.00 22 13 32.90159 -11 38 45.4183 29.035042516 18.70 0.67 159.49 -0.9848E-03 -0.3779E-03 10.27799