Predictions for Grazing Occultation of ZC 2066 & SAO 158556, 2008 Aug 8

The two stars form a double with graze paths separated by just over 10 km. On the graze line for ZC 2066, the secondary SAO 158556 will disappear a few minutes earlier and reappear at the lit limb. On the graze line for SAO 158556, the primary ZC 2066 will miss the Moon's limb.

This is a multiple system, Occult lists two other, much closer, components of ZC 2066. Thus stepped events are likely.

Grazing Occultation of    2066 SA1      Magnitude   6.6 
Date   2008 August  8    (Friday)     Nominal site altitude  0m

E. Longit.   Latitude     U.T.    Sun  Moon   TanZ   PA    WA      CA
   o  '  "    o  '  "   h  m  s   Alt Alt Az          o     o      o
 172  0  0  -41 18  5   9 49 37       35 273  1.42 196.5 178.20   2.68S
 172 10  0  -41 16 56   9 49 47       35 273  1.43 196.5 178.16   2.72S
 172 20  0  -41 15 46   9 49 56       35 273  1.43 196.4 178.12   2.76S
 172 30  0  -41 14 35   9 50  5       35 273  1.44 196.4 178.08   2.80S
 172 40  0  -41 13 24   9 50 15       35 273  1.45 196.4 178.04   2.84S
 172 50  0  -41 12 11   9 50 24       34 273  1.46 196.3 178.01   2.88S
 173  0  0  -41 10 57   9 50 33       34 273  1.47 196.3 177.97   2.92S
 173 10  0  -41  9 43   9 50 42       34 272  1.48 196.2 177.93   2.95S
 173 20  0  -41  8 27   9 50 51       34 272  1.49 196.2 177.89   2.99S
 173 30  0  -41  7 11   9 51  0       34 272  1.49 196.2 177.85   3.03S
 173 40  0  -41  5 53   9 51  9       34 272  1.50 196.1 177.82   3.07S
 173 50  0  -41  4 35   9 51 18       33 272  1.51 196.1 177.78   3.11S
 174  0  0  -41  3 16   9 51 27       33 272  1.52 196.0 177.74   3.14S
 174 10  0  -41  1 56   9 51 36       33 271  1.53 196.0 177.70   3.18S
 174 20  0  -41  0 35   9 51 45       33 271  1.54 196.0 177.67   3.22S
 174 30  0  -40 59 13   9 51 54       33 271  1.55 195.9 177.63   3.26S
 174 40  0  -40 57 50   9 52  3       33 271  1.56 195.9 177.59   3.29S
 174 50  0  -40 56 26   9 52 12       33 271  1.57 195.9 177.55   3.33S
 175  0  0  -40 55  2   9 52 20       32 271  1.57 195.8 177.52   3.37S
 175 10  0  -40 53 36   9 52 29       32 271  1.58 195.8 177.48   3.40S
 175 20  0  -40 52 10   9 52 38       32 270  1.59 195.8 177.44   3.44S
 175 30  0  -40 50 42   9 52 46       32 270  1.60 195.7 177.41   3.48S
 175 40  0  -40 49 14   9 52 55       32 270  1.61 195.7 177.37   3.51S
 175 50  0  -40 47 45   9 53  3       32 270  1.62 195.6 177.34   3.55S
 176  0  0  -40 46 15   9 53 12       32 270  1.63 195.6 177.30   3.58S
 176 10  0  -40 44 44   9 53 20       31 270  1.64 195.6 177.26   3.62S
 176 20  0  -40 43 12   9 53 29       31 270  1.65 195.5 177.23   3.66S
 176 30  0  -40 41 39   9 53 37       31 269  1.66 195.5 177.19   3.69S

Path coordinates are referred to WGS84 (as used by GPS).

   2066 is multiple :   6.8  7.7   0.100"    0.0 :   7.3  8.3   1.20"   88.0 :   6.6  6.9   35"  295.0
Graze Path of component #2  0.18km South, and 0.1 secs. earlier cf. primary.
Graze Path of component #3  0.66km South, and 2.8 secs. later cf. primary.
Graze Path of component #4  10.64km South, and 83.6 secs. earlier cf. primary.

                Librations  Long +3.22   Lat +6.53
                            P +177.6     D +6.9
      Illumination of moon  45%+
        Elongation of Moon  84
    Vertical Profile Scale  1.92 km/arcsec at mean distance of moon
   Horizontal Scale Factor  1.59 deg/min

Limiting Magnitudes for various telescope apertures (in mm)
      CA\Tdia  50   100   150   200   250   300   350
    -0.3      3.1   4.5   5.2   5.6   5.9   6.1   6.2
     1.7      4.9   6.3   7.0   7.5   7.8   8.1   8.2
     3.7      4.9   6.3   7.1   7.5   7.9   8.1   8.2
     5.7      5.7   7.1   7.9   8.4   8.7   9.0   9.2
     7.7      5.7   7.1   7.9   8.4   8.8   9.0   9.2

Grazing Occultation of  158556 WA2      Magnitude   6.8 
Date   2008 August  8    (Friday)     Nominal site altitude  0m

E. Longit.   Latitude     U.T.    Sun  Moon   TanZ   PA    WA      CA
   o  '  "    o  '  "   h  m  s   Alt Alt Az          o     o      o
 172  0  0  -41 23 58   9 48 10       35 274  1.41 196.6 178.28   2.61S
 172 10  0  -41 22 51   9 48 20       35 274  1.41 196.5 178.24   2.65S
 172 20  0  -41 21 43   9 48 29       35 273  1.42 196.5 178.20   2.69S
 172 30  0  -41 20 33   9 48 39       35 273  1.43 196.5 178.16   2.73S
 172 40  0  -41 19 23   9 48 48       35 273  1.44 196.4 178.12   2.77S
 172 50  0  -41 18 12   9 48 57       35 273  1.45 196.4 178.08   2.81S
 173  0  0  -41 17  0   9 49  7       35 273  1.45 196.3 178.04   2.84S
 173 10  0  -41 15 48   9 49 16       34 273  1.46 196.3 178.00   2.88S
 173 20  0  -41 14 34   9 49 25       34 273  1.47 196.3 177.96   2.92S
 173 30  0  -41 13 19   9 49 34       34 272  1.48 196.2 177.93   2.96S
 173 40  0  -41 12  3   9 49 43       34 272  1.49 196.2 177.89   3.00S
 173 50  0  -41 10 47   9 49 52       34 272  1.50 196.2 177.85   3.03S
 174  0  0  -41  9 29   9 50  1       34 272  1.51 196.1 177.81   3.07S
 174 10  0  -41  8 11   9 50 10       33 272  1.51 196.1 177.77   3.11S
 174 20  0  -41  6 52   9 50 19       33 272  1.52 196.0 177.74   3.15S
 174 30  0  -41  5 31   9 50 28       33 271  1.53 196.0 177.70   3.18S
 174 40  0  -41  4 10   9 50 37       33 271  1.54 196.0 177.66   3.22S
 174 50  0  -41  2 48   9 50 46       33 271  1.55 195.9 177.63   3.26S
 175  0  0  -41  1 25   9 50 55       33 271  1.56 195.9 177.59   3.30S
 175 10  0  -41  0  1   9 51  3       33 271  1.57 195.9 177.55   3.33S
 175 20  0  -40 58 37   9 51 12       32 271  1.58 195.8 177.52   3.37S
 175 30  0  -40 57 11   9 51 21       32 271  1.59 195.8 177.48   3.41S
 175 40  0  -40 55 44   9 51 29       32 270  1.60 195.8 177.44   3.44S
 175 50  0  -40 54 17   9 51 38       32 270  1.61 195.7 177.41   3.48S
 176  0  0  -40 52 49   9 51 46       32 270  1.62 195.7 177.37   3.52S
 176 10  0  -40 51 19   9 51 55       32 270  1.62 195.6 177.33   3.55S
 176 20  0  -40 49 49   9 52  3       31 270  1.63 195.6 177.30   3.59S
 176 30  0  -40 48 18   9 52 12       31 270  1.64 195.6 177.26   3.62S

Path coordinates are referred to WGS84 (as used by GPS).

 158556 is double :   6.9  6.6   35"  115.0
Graze Path of component #2  10.57km North, and 83.8 secs. later cf. primary.

                Librations  Long +3.22   Lat +6.53
                            P +177.6     D +6.9
      Illumination of moon  45%+
        Elongation of Moon  84
    Vertical Profile Scale  1.92 km/arcsec at mean distance of moon
   Horizontal Scale Factor  1.59 deg/min

Limiting Magnitudes for various telescope apertures (in mm)
      CA\Tdia  50   100   150   200   250   300   350
    -0.4      3.1   4.5   5.2   5.6   5.9   6.1   6.2
     1.6      4.9   6.3   7.1   7.5   7.8   8.1   8.2
     3.6      4.9   6.3   7.1   7.5   7.9   8.1   8.3
     5.6      5.7   7.1   7.9   8.4   8.7   9.0   9.2
     7.6      5.7   7.1   7.9   8.4   8.8   9.0   9.2

Lunar Limb Profile

Lunar Limb Profile