An ephemeris is a table of values that gives the positions of an astronomical object in the sky over a range of times, while geocentric means "as seen from Earth's center." The following table is a geocentric ephemeris for Comet ISON (C/2012 S1) every day at 00:00 Coordinated Universal Time for the 2-month period Nov-Dec 2013. It was generated using the IAU Minor Planet & Comet Ephemeris Service. A key to the terms in the table appear below it.

Comet ISON reaches perihelion on Nov 29 when it passes within 0.029 AUs of the Sun. On Dec 27, the comet makes its closest approach to Earth at a distance of 0.429 AUs. It will then be well placed in northern skies at an elongation of 80° from the Sun.

Geocentric Ephemeris for Comet ISON (C/2012 S1)

00:00 UTC (Coordinated Universal Time)

  Date       R.A. (J2000) Dec.    Delta     r     El.    Ph.   m2     Sky Motion
                                                                      "/min    P.A.
2013 11 01   11.2051  +06.375     1.230   0.998   52.0  51.6          3.53    117.5
2013 11 02   11.2908  +05.706     1.203   0.973   51.6  53.0          3.69    117.7
2013 11 03   11.3803  +05.003     1.176   0.949   51.1  54.4          3.87    117.8
2013 11 04   11.4740  +04.262     1.149   0.924   50.5  55.9          4.05    117.9
2013 11 05   11.5720  +03.484     1.123   0.898   49.8  57.5          4.25    118.0
2013 11 06   11.6747  +02.664     1.097   0.873   49.1  59.1          4.47    118.1
2013 11 07   11.7825  +01.801     1.072   0.847   48.3  60.9          4.69    118.1
2013 11 08   11.8957  +00.893     1.048   0.820   47.3  62.7          4.93    118.1
2013 11 09   12.0147  -00.061     1.024   0.793   46.3  64.6          5.19    118.1
2013 11 10   12.1398  -01.064     1.002   0.766   45.2  66.6          5.46    118.1

2013 11 11   12.2715  -02.116     0.981   0.738   44.0  68.7          5.74    118.0
2013 11 12   12.4102  -03.218     0.960   0.710   42.7  70.9          6.03    117.9
2013 11 13   12.5564  -04.370     0.941   0.681   41.2  73.2          6.33    117.7
2013 11 14   12.7103  -05.570     0.924   0.651   39.6  75.6          6.64    117.4
2013 11 15   12.8725  -06.816     0.908   0.621   37.9  78.2          6.96    117.1
2013 11 16   13.0434  -08.104     0.894   0.590   36.1  80.8          7.28    116.7
2013 11 17   13.2232  -09.429     0.881   0.558   34.1  83.5          7.60    116.2
2013 11 18   13.4124  -10.783     0.871   0.526   32.1  86.3          7.92    115.6
2013 11 19   13.6112  -12.158     0.864   0.492   29.9  89.3          8.23    114.8
2013 11 20   13.8198  -13.542     0.858   0.457   27.5  92.2          8.52    114.0

2013 11 21   14.0383  -14.921     0.856   0.421   25.1  95.3          8.80    113.0
2013 11 22   14.2671  -16.281     0.857   0.383   22.6  98.3          9.07    111.8
2013 11 23   14.5062  -17.605     0.861   0.344   19.9 101.3          9.32    110.4
2013 11 24   14.7563  -18.872     0.869   0.302   17.2 104.2          9.58    108.7
2013 11 25   15.0183  -20.061     0.881   0.257   14.4 107.0          9.88    106.8
2013 11 26   15.2948  -21.144     0.899   0.207   11.4 109.2         10.30    104.3
2013 11 27   15.5922  -22.075     0.923   0.152    8.3 110.4         11.05    100.8
2013 11 28   15.9317  -22.721     0.958   0.085    4.7 107.2         13.20    094.0
2013 11 29   16.3895  -20.074     0.979   0.029    1.6 104.2         15.69    005.8
2013 11 30   16.3599  -16.430     0.914   0.112    5.2 127.4          6.82    348.0

2013 12 01   16.3236  -14.058     0.869   0.174    8.0 128.1          5.55    347.5
2013 12 02   16.2935  -12.001     0.832   0.227   10.5 127.3          5.03    348.5
2013 12 03   16.2686  -10.080     0.799   0.274   13.0 126.2          4.78    349.9
2013 12 04   16.2478  -08.219     0.769   0.318   15.3 124.9          4.66    351.3
2013 12 05   16.2305  -06.380     0.741   0.359   17.7 123.5          4.63    352.7
2013 12 06   16.2161  -04.537     0.715   0.398   20.0 122.0          4.66    354.0
2013 12 07   16.2043  -02.670     0.690   0.435   22.4 120.5          4.73    355.2
2013 12 08   16.1948  -00.764     0.667   0.471   24.7 118.9          4.83    356.3
2013 12 09   16.1874  +01.194     0.645   0.505   27.1 117.3          4.97    357.2
2013 12 10   16.1819  +03.214     0.624   0.538   29.5 115.7          5.14    358.1

2013 12 11   16.1783  +05.307     0.604   0.571   32.0 114.0          5.33    358.9
2013 12 12   16.1764  +07.482     0.584   0.602   34.5 112.2          5.55    359.6
2013 12 13   16.1762  +09.749     0.566   0.633   37.1 110.3          5.79    000.2
2013 12 14   16.1776  +12.115     0.549   0.663   39.7 108.3          6.05    000.8
2013 12 15   16.1807  +14.589     0.532   0.692   42.4 106.3          6.32    001.3
2013 12 16   16.1854  +17.176     0.517   0.721   45.2 104.1          6.62    001.7
2013 12 17   16.1917  +19.882     0.503   0.749   48.1 101.9          6.92    002.1
2013 12 18   16.1998  +22.710     0.489   0.776   51.1  99.5          7.23    002.5
2013 12 19   16.2097  +25.663     0.477   0.804   54.1  97.1          7.54    002.8
2013 12 20   16.2215  +28.738     0.466   0.830   57.3  94.5          7.85    003.1

2013 12 21   16.2354  +31.933     0.457   0.857   60.5  91.9          8.14    003.4
2013 12 22   16.2516  +35.240     0.448   0.882   63.8  89.1          8.42    003.6
2013 12 23   16.2703  +38.648     0.442   0.908   67.1  86.3          8.66    003.9
2013 12 24   16.2919  +42.143     0.436   0.933   70.5  83.4          8.86    004.2
2013 12 25   16.3170  +45.707     0.432   0.958   73.9  80.5          9.01    004.5
2013 12 26   16.3460  +49.319     0.430   0.983   77.2  77.5          9.10    004.8
2013 12 27   16.3800  +52.955     0.429   1.007   80.6  74.5          9.14    005.2
2013 12 28   16.4200  +56.590     0.430   1.031   83.9  71.6          9.11    005.7
2013 12 29   16.4679  +60.198     0.432   1.054   87.2  68.7          9.02    006.2
2013 12 30   16.5261  +63.754     0.436   1.078   90.3  65.8          8.87    006.9

Perturbed ephemeris based on elements from MPEC 2012-VA1.

• R.A. - Apparent Right Ascension of the comet for the true equator and equinox of date (decimal degrees).
• Dec. - Apparent Declination of the comet for the true equator and equinox of date (decimal degrees).
• Delta - Distance of the comet from Earth in astronomical units (1 a.u. = 149,597,871 km).
• r - Distance of the comet from the Sun in astronomical units (1 a.u. = 149,597,871 km).
• El. - Solar Elongation of the comet; Defined as geocentric angular position of the comet with respect to the Sun (degrees).
  'E' is east (evening sky) and 'W' is west (morning sky).
• Ph. - Phase Angle; Defined as angle between the Sun and Earth as seen from the comet (degrees).
• m2 - Apparent Magnitude; Not calculated due to large uncertainties.

Links to Geocentric Ephemerides for the Sun, Moon and Planets

Geocentric Ephemerides for the Sun, Moon and Planets
Sun	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Moon	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Mercury	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Venus	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Mars	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Jupiter	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Saturn	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Uranus	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Neptune	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022

Acknowledgement

These predictions were made using the JPL DE405 planetary and lunar ephemerides and include both nutations and librations (referred to the International Celestial Reference Frame). The value for Delta-T (the difference between Coordinated Universal Time and Terrestrial Time) on 2011 Jan 01 is 66.2 seconds. All calculations are by Fred Espenak, and he assumes full responsibility for their accuracy.

Permission is freely granted to reproduce this data when accompanied by the acknowledgment:

"Geocentric Ephemeris for the Sun Courtesy of Fred Espenak, www.Astropixels.com".

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