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Lunar Occultation of Saturn, 2019 August 12


Saturn will be occulted by the 91% lit Moon on 2019 August 12. The occultation is visible from North Island places north of Masterton Along a band, running west to east including Masterton itself and Carterton a grazing occultation will occur. The moon will miss Saturn for places further south including all the South Island. The occultation is also visible from much of the east coast region of Australia from about 150 km south of Canberra northwards.

Event times

Times are as shown in Dave Herald's OCCULT programme.

Predicted times (UTC) of Disappearances behind the moon and Reappearances at the other side of the moon for a number of North Island places are given. Disappearances are at the dark limb of the moon while reappearances are at the sunlit limb of the moon.

Predictions are also given for places near the east coast of Australia: Times of disappearance and Times of reappearance.

The predictions show the place name, the predicted time (UT) of occultation, the altitude of the Sun below the horizon if less than 12° and the altitude of the moon at the predicted time.

Two angles show the position of Saturn (or Titan) round the moon's limb. CA is the cusp angle which is the angle round the Moon's limb measured from the S(outh) lit cusp. The value is negative if the event is at the sunlit limb as is the case reappearances The PA shows the position as measured from the Moon's north pole through east. The CA is probably the most useful for visual observers, although Saturn is should not be difficult to find for disappearances. They are needed as a guide of where to look for the reappearance.

Duration of Events

The predicted times are for the when the centre of Saturn's disk is at the moon's limb. Because of its extended nature, Saturn takes a considerable time to completely disappear or reappear. The rings take even longer. The times for some places in New Zealand and Australia follow
New Zealand      Whangarei    Auckland    Palmerston N    Levin
Disappearance
    Saturn       +/-35.8s     +/-39.3s     +/- 93.0s     +/-154.4s 
    Rings        +/-70.5s     +/-73.6s     +/-124.9s     +/-120.6s
Reappearance 
    Saturn       +/-35.4s     +/-38.6s     +/- 90.8s     +/-127.2s
    Rings        +/ 59.9s     +/-60.3c     +/- 99.0s     +/-119.5s

Australia       Rockhampton   Brisbane     Newcastle   Sydney      Canberra
 Disappearances    
    Saturn       +/-52.2s     +/-54.3s     +/-58.7s    +/-61.1s    +/-73.8s
    Rings        +/-23.5s     +/-25.5s     +/-33.3s    +/-37.0s    +/-54.1ss
 Reappearances 
    Saturn       +/-61.3s     +/-61.9s     +/-63.2s    +/-64.9s    +/-76.6s
    Rings        +/-27.4s     +/-29.0s     +/-36.2s    +/-39.8s    +/-56.7s
Duration times are largest for places to the south near the line of grazing occultation.

The grazing occultation

At the southern limit of the occultation, Saturn will skim along the edge of the Moon. Since Saturn presents an extended object there will be a band along which Saturn will be partly obscured by the moon, but not be completely hidden. The centre of Saturn's disk should skim the edge of the Moon as seen from Masterton. The entire grazing band is just under 40 km wide. To the north Otaki is 20 km north of Masterton. Here Saturn will disappear behind the moon entirely for about 5 minutes. To the south Featherston is 19 km south of Masterton. As seen from here the edge of Saturn will just about touch the moon's limb, but otherwise remain visible. Places between Featherston and Otaki in latitude will see increasing amounts of Saturn obscured the further north one goes.

In Australia the mid graze line is at Albury, NSW at 08:54:32 UT but at a cusp angle -12° south. To the west, Mildura Vic is 19km north of the mid graze line. The occultation takes place in twilight and the total event lasts for about 8 minutes. Further east, the graze line crosses the coast near Merrimbula, NSW. From 0ther parts of Victoria the moon will be seen to miss Saturn altogether.

Mid graze times for a number of NZ places and their distance from the mid graze through Masterton.

Occultation of Titan

A modest telescope is likely to show up Saturn's largest satellite, Titan. It will be occulted about 10 minutes before Saturn itself. NZ times for the disappearances of Titan, Australian times for disappearance of Titan. The reappearance of Titan is not likely to be observable as it takes place at the sunlit limb of the moon which will be too bright to see Titan as it emerges.

Times of Disappearance of Saturn for NZ

                                      U.T.  Sun Moon CA  PA 
Location                             h  m  s Alt Alt   o   o 

 1 Auckland                          9 15 45     72  36S 139
 2 Baylys Beach                      9 10 24     72  40S 135
 3 Dannevirke                        9 35 39     72  13S 162
 4 East Cape                         9 26 36     74  32S 142
 5 Gisborne                          9 29 40     73  26S 148
 6 Hamilton                          9 19 59     72  31S 143
 7 Hastings                          9 32 49     72  18S 156
 8 Levin                             9 38 20     71   7S 167
 9 Napier                            9 31 58     72  20S 155
10 New Plymouth                      9 23 39     71  22S 152
11 North Cape                        9  4 30     71  46S 128
12 Otaki                             9 40 15     71   4S 170
13 Palmerston North                  9 36 14     71  11S 164
14 Rotorua                           9 23 34     73  29S 145
15 Taupo                             9 25 39     72  25S 149
16 Tauranga                          9 21 22     73  32S 143
17 Thames                            9 18 12     73  34S 140
18 Wanganui                          9 31  8     71  15S 159
19 Wellsford                         9 13  5     72  38S 136
20 Whakatane                         9 24 21     73  30S 144
21 Whangarei                         9 10 50     72  41S 133

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Times of Reappearance of Saturn for NZ

                                       U.T.  Sun Moon CA  PA 
Location                             h  m  s Alt Alt   o   o 

 1 Auckland                         10 15 54     75 -45S 219
 2 Baylys Beach                     10 16 27     76 -50S 224
 3 Dannevirke                       10  1 48     72 -21S 195
 4 East Cape                        10 20 46     73 -39S 213
 5 Gisborne                         10 15 13     73 -33S 207
 6 Hamilton                         10 13 38     75 -40S 214
 7 Hastings                         10  7 25     73 -26S 200
 8 Levin                             9 55 47     72 -16S 190
 9 Napier                           10  8 39     73 -28S 201
10 New Plymouth                     10  5 14     73 -32S 206
11 North Cape                       10 18 50     78 -58S 231
12 Otaki                             9 53 25     72 -13S 187
13 Palmerston North                  9 59 33     72 -19S 193
14 Rotorua                          10 14 11     74 -37S 211
15 Taupo                            10 11 22     74 -34S 208
16 Tauranga                         10 15 54     74 -40S 214
17 Thames                           10 16 36     75 -44S 217
18 Wanganui                         10  1 42     73 -24S 198
19 Wellsford                        10 17 10     76 -48S 222
20 Whakatane                        10 16 32     74 -38S 212
21 Whangarei                        10 18 25     76 -51S 225

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Times of Grazes (NZ)

  Place          Mid graze time          Distance from mid line
 
Levin            09:47:03 (total occn.)     37 km north
Otaki            09:46:46                   20 km north
Masterton        09:47:46                    0 km 
Carterton        09:47:32                   11 km south    
Featherston      09:47:09                   19 km south 
Titahi Bay       09:46:11 (miss)            21 km south
Carter Obs       09:46:05 (miss)            39 km south

Cusp angle for the graze is -4° south.  

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Times for disappearance of Titan for NZ

                                       U.T.  Sun Moon CA  PA 
Location                             h  m  s Alt Alt   o   o 

 1 Auckland                          9  4 55     71  39S 136
 2 Baylys Beach                      8 59 55     70  42S 132
 3 Carterton                         9 27 15     70  11S 164
 4 Dannevirke                        9 21 54     71  19S 155
 5 East Cape                         9 15 24     73  36S 138
 6 Featherston                       9 27 25     70  10S 165
 7 Gisborne                          9 17 52     72  30S 144
 8 Hamilton                          9  8 53     71  34S 140
 9 Hastings                          9 19 55     71  24S 151
10 Levin                             9 22 55     70  15S 159
11 Masterton                         9 26 36     70  12S 162
12 Napier                            9 19 11     71  25S 150
13 New Plymouth                      9 11 49     70  26S 148
14 North Cape                        8 54 22     70  49S 126
15 Otaki                             9 23 58     70  14S 161
16 Palmerston North                  9 21 49     70  18S 157
17 Rotorua                           9 12  9     72  33S 142
18 Taupo                             9 13 57     71  30S 145
19 Tauranga                          9 10 19     72  35S 139
20 Thames                            9  7 18     71  38S 137
21 Titahi Bay                        9 26 40     70   9S 165
22 Wanganui                          9 18 10     70  21S 154
23 Wellsford                         9  2 29     71  41S 133
24 Whakatane                         9 12 59     72  34S 140
25 Whangarei                         9  0 25     71  44S 131

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Times for Australia

For several of the places in Australia the Sun will only be a few degrees below the horizon at the disappearance. The altitude of the Sun is shown where it is less then 12° below the horizon.

Australia, Times of Disappearance of Saturn

      
                                       U.T.  Sun Moon CA  PA 
Location                             h  m  s Alt Alt   o   o 

 1 Brisbane                          8 16 15 -12 46  53S 121
 2 Broken Hill                       8 25 35  -5 38  15S 160
 3 Canberra                          8 41  2     48  11S 163
 4 Dubbo                             8 26 30 -11 45  28S 147
 5 Mackay                            8  1 30  -4 38  69S 105
 6 Newcastle                         8 30 31     48  30S 145
 7 Rockhampton                       8  6  4  -7 41  64S 111
 8 Sydney                            8 33 39     48  25S 150
 9 Tamworth                          8 23 54     46  37S 138
10 Towoomba                          8 15 23 -11 45  52S 123
11 Wollongong                        8 36 15     48  21S 154

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Australia, Times of Reaappearance of Saturn

                                       U.T.  Sun Moon CA  PA 
Location                             h  m  s Alt Alt   o   o 

 1 Brisbane                          9 34 21     63 -78S 252
 2 Broken Hill                       9  0 55     46 -41S 215
 3 Canberra                          9 12 35     54 -35S 209
 4 Dubbo                             9 19  5     56 -53S 227
 5 Mackay                            9 23 46     57 -83N 271
 6 Newcastle                         9 25 56     60 -54S 227
 7 Rockhampton                       9 27 53     59 -89N 265
 8 Sydney                            9 22 30     58 -48S 222
 9 Tamworth                          9 26 39     59 -61S 235
10 Towoomba                          9 31 40     62 -77S 251
11 Wollongong                        9 20 36     57 -44S 218

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Australia, Times of Disappearance of Titan

                                       U.T.  Sun Moon CA  PA                 
Location                             h  m  s Alt Alt   o   o 

 1 Brisbane                          8  8  5 -10 44  54S 120
 2 Broken Hill                       8 17 20  -3 37  16S 159
 3 Canberra                          8 31 41     46  14S 161
 4 Dubbo                             8 18 12  -9 43  29S 145
 5 Mackay                            7 53 51  -2 36  70S 105
 6 Newcastle                         8 21 59     46  31S 143
 7 Rockhampton                       7 58 15  -5 39  64S 110
 8 Sydney                            8 24 57     46  26S 149
 9 Tamworth                          8 15 35 -11 44  38S 137
10 Towoomba                          8  7 17  -9 43  52S 122
11 Wollongong                        8 27 20     47  23S 152