Stellar Occultations by Pluto 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 Feb  7  20 23.4   84.2s 12.5  1.8   1.6    42 24678175  18 27  5.985 -18 48 22.23
2011 Feb 17  13 37.3   97.0s 14.4  0.6   0.5    52 24679565  18 28 11.387 -18 47 35.44
2011 Feb 18  14 57.3   98.6s 14.2  0.7   0.5    53 24679751  18 28 17.934 -18 47 29.46
2011 Mar 10  15 27.8    158s 15.8  0.21  0.27   73 24682369  18 29 58.914 -18 45 44.59
2011 May 22   6 25.4    130s 15.5  0.24  0.29  144 24680978  18 29  3.068 -18 44 19.91
2011 Jun  5   6  7.4    109s 15.7  0.21  0.14  157 24678943  18 27 47.910 -18 45 37.42
2011 Jun  7   2 30.6    107s 14.9  0.39  0.34  159 24678649  18 27 37.064 -18 45 50.50
2011 Jun 23  11 22.9   99.1s 14.4  0.6   0.7   174 24677089  18 25 55.483 -18 48  7.12
2011 Jun 24  10 30.9   98.8s 14.8  0.42  0.30  174 24676987  18 25 49.303 -18 48 16.57
2011 Jun 27  14 22.6   98.7s 13.5  1.0   0.8   175 24676603  18 25 29.000 -18 48 47.57
2011 Jul 25   2  7.9    113s 15.8  0.19  0.27  153 24674204  18 22 40.116 -18 54 11.90
2011 Aug 21   5 12.9    188s 13.7  1.0   0.8   127 24425828  18 20 38.389 -19  0 30.79
2011 Oct 19   7 35.4    141s 15.5  0.26  0.32   69 24426086  18 21  6.579 -19 13 48.25
2011 Dec  3  12 15.4   71.7s 15.9  0.21  0.14   25 24430494  18 26  4.045 -19 19 27.55
2011 Dec  4   8 26.7   71.3s 14.8  0.49  0.6    25 24430624  18 26 11.129 -19 19 30.67
2011 Dec  6   7  3.1   70.5s 14.8  0.46  0.40   23 24430910  18 26 27.604 -19 19 36.86
2012 Jan  4  11  9.8   66.4s 15.7  0.22  0.24    7 24437002  18 30 48.000 -19 19 53.78
2012 Apr  4   0 29.0    731s 15.4  0.29  0.21   95 24444560  18 39 38.740 -19 13 23.48
2012 Jun 11   9 44.9    105s 14.6  0.49  0.5   162 24441137  18 36  5.306 -19 17 17.93
2012 Jun 12  23 16.1    104s 16.1  0.15  0.21  163 24440943  18 35 55.855 -19 17 32.53
2012 Jul 10  19  7.9    101s 14.9  0.39  0.29  168 24438925  18 32 59.940 -19 22 43.25
2012 Oct  3  11  5.5    278s 15.3  0.34  0.41   86 24192530  18 28 58.948 -19 41 40.40
2012 Nov  6   7 28.9   98.8s 13.9  0.9   0.9    53 24194403  18 31 20.195 -19 46 44.08
2012 Nov 24   0 54.2   78.4s 15.0  0.42  0.30   36 24195914  18 33 23.101 -19 48  9.01
2012 Nov 24  21 13.4   77.7s 14.8  0.49  0.5    35 24195986  18 33 29.608 -19 48 11.84
2012 Nov 28  16 13.0   75.2s 15.3  0.34  0.5    31 24196365  18 33 59.428 -19 48 22.99
2012 Dec 12   9 22.9   68.9s 13.5  1.2   1.0    18 24197953  18 35 54.281 -19 48 39.40
2012 Dec 18  16 30.3   67.3s 14.5  0.6   0.6    12 24198884  18 36 49.688 -19 48 36.75

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