Stellar Occultations by Charon in 2011 and 2012 of UCAC Stars

The following occultation predictions are based on the nominal catalog positions of the star catalogs, they have not been refined by special astrometry. Therefore, the predictions should only be used as a first guess for planning or preparing astrometrical observations.

     Date      U.T.    Durn  Star   Mag-Drop Elon  Star     R.A. (J2000)  Dec.       
   y   m  d   h   m   sec/m   mag    V     R     o  No.       h  m   s      o  '   "  
.... ... ..  .. ....  ..... ....  .... ....  ..  ........  .. .. ...... ... .. .....
2011 Jan 10  13 24.5  33.9s 13.9  2.2  2.0   15  24674578  18 23 15.268 -18 49 51.66
2011 Jan 20   8 13.8  35.9s 16.1  0.7  0.7   24  24675797  18 24 40.224 -18 49 32.57
2011 Feb  1  23 55.2  39.8s 15.5  1.0  1.0   37  24677523  18 26 22.543 -18 48 48.64
2011 Feb  4   2 55.2  40.4s 15.6  1.0  0.9   39  24677734  18 26 38.627 -18 48 38.64
2011 Feb 18  14 47.9  49.4s 14.2  2.0  1.6   53  24679751  18 28 17.934 -18 47 29.46
2011 Feb 26  21 43.4  58.5s 16.3  0.6 0.44   61  24681035  18 29  5.313 -18 46 46.69
2011 Mar  4  13 49.9  67.0s 15.4  1.1  1.2   67  24681787  18 29 33.297 -18 46 16.81
2011 May  7  16  2.5  90.1s 15.0  1.3  1.1  129  24682502  18 30  4.462 -18 43 34.81
2011 May 18   3 35.5  71.1s 15.2  1.2  1.5  140  24681513  18 29 22.374 -18 44  2.61
2011 May 22   6 12.9  65.2s 15.5  1.0  1.1  144  24680978  18 29  3.068 -18 44 19.91
2011 May 24   7 26.7  63.8s 14.6  1.6  1.6  146  24680718  18 28 52.959 -18 44 28.12
2011 Jun  7   2 40.2  54.1s 14.9  1.4  1.2  159  24678649  18 27 37.064 -18 45 50.50
2011 Jun 19  12 44.3  50.6s 13.3  2.7  2.3  171  24677496  18 26 20.635 -18 47 29.53
2011 Jun 23  11 12.2  49.7s 14.4  1.7  1.9  174  24677089  18 25 55.483 -18 48  7.12
2011 Jul 25   1 57.2  56.4s 15.8  0.8  1.0  153  24674204  18 22 40.116 -18 54 11.90
2011 Nov 18  15 46.6  40.9s 13.6  2.5  2.3   40  24428262  18 24  6.352 -19 18 13.34
2011 Dec 20  13 57.0  33.4s 17.9  0.17 0.12   9  24433651  18 28 33.223 -19 20  2.80
2011 Dec 25   8 46.2  33.3s 16.3  0.6  0.6    5  24434907  18 29 16.454 -19 20  4.83
2011 Dec 26   4 15.0  33.2s 15.8  0.9  0.6    5  24435148  18 29 23.807 -19 20  3.55
2012 Jan  4  11  2.2  33.4s 15.7  0.9  1.0    7  24437002  18 30 48.000 -19 19 53.78
2012 Feb 15  18 58.8  45.6s 15.5  1.0  1.0   48  24441570  18 36 31.472 -19 17  0.29
2012 Jun 11   9 53.8  52.9s 14.6  1.6  1.7  162  24441137  18 36  5.306 -19 17 17.93
2012 Jun 29  11 59.0  49.8s 14.0  2.1  2.2  176  24439941  18 34 11.683 -19 20 25.79
2012 Jul 10  18 57.0  50.5s 14.9  1.4  1.1  168  24438925  18 32 59.940 -19 22 43.25
2012 Aug 15  18 25.8  78.0s 14.9  1.4  1.1  134  24193267  18 29 49.620 -19 30 57.42
2012 Oct 13   4 33.8  91.7s 14.8  1.5  1.8   77  24192902  18 29 25.182 -19 43 25.20
2012 Nov  6   7 17.5  49.7s 13.9  2.2  2.2   53  24194403  18 31 20.195 -19 46 44.08
2012 Nov 24   0 52.0  39.2s 15.0  1.4  1.1   36  24195914  18 33 23.101 -19 48  9.01
2012 Nov 24  21  5.5  39.0s 14.8  1.6  1.6   35  24195986  18 33 29.608 -19 48 11.84
2012 Dec 23   0 43.0  33.6s 13.3  2.9  3.0    8  24199500  18 37 28.484 -19 48 31.63
2013 Jan  2   2 53.5  33.2s 14.9  1.5  1.7    4  24200794  18 38 59.514 -19 48  7.12

Calculated using  WINOCCULT Version 4.0.8.16 with DE 423 and an position offset according to the following procedure:

An offset of Pluto's position versus DE413 is calculated by Bruno Sicardy from real occultations observed in the last 10 years. It may not be correct for the future, but may be the best approximation we can do at the moment.

This offset versus DE413 is converted in an offset versus DE423, which is the basis of the latest version of WINOCCULT 4.0.4.16.
Because of the approximate position of the stars, which may cause errors larger than Pluto's diameter, the offsets have been calculated only once for each year, at 2011.5 and 2012.5

2011:Offset in Declination: +75 mas, in Rectascension: +88 mas

2012:Offset in Declination: +86 mas, in Rectascension: +115 mas

UCAC stars have been used without any restriction. Events with a reasonable area of visibility have a link to a map with local circumstances. But keep in mind, relatively large errors are possible.

These data are only a first basis for your observation plans.

The table gives the following data:

Date and UT
The UT date and time of closest approach to the specified site [that is, the time listed here does depend on the site location, for both Local and Global summaries].

Duration 
This column gives the predicted maximum duration, in seconds or minutes.
 
Star mag
Star magnitude - visual

Mag drop V
Magnitude drop at occultation - based on visual magnitude

Mag drop R
Magnitude drop at occultation - based on the star's red magnitude, and an asteroid color (B-V) of 0.83. This may be a better guide for CCD observers

Elong
The solar elongation of the star, in degrees

Star number
The 2UCAC number of the star being occulted or the Tycho number

RA Dec
The J2000 coordinates of the star

Wolfgang Beisker

International Occultation Timing Association - European Section
Research and Development