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Events of the Galilean Satellites for September 2010


Table of Events visible from New Zealand for September 2010.

Events of Jupiter's Galilean Satellites

Eclipses, occultations, transits and shadow transit of all four Galilean satellites will be occurring at regular intervals during September. A table of events visible during the month from NZ is included.

Eclipses occur when a satellite moves through the shadow of Jupiter. As it moves into the shadow the satellite will gradually fade from view and disappear. When it comes out of the shadow a faint spot of light will appear and gradually brighten.
Occultations occur when a satellite moves behind Jupiter as seen from the Earth. Hence during an occultation the satellite is hidden by the planet.
Transits occur when a satellite moves across the face of Jupiter as seen from the Earth.
Shadow transits occur when the shadow of the satellite cast by the Sun moves across the face of the planet

Occultations always start at the western limb of Jupiter and end at the east. Transits always start at the eastern limb of the planet and end at the west. In both cases the satellite will appear to "sink" into the bright limb of Jupiter at the ingress and gradually emerge from the limb of Jupiter at an egress.

In general eclipse events take place when the satellite is a small distance away from Jupiter as seen from the Earth. Before opposition, as in early September, events occur to the west of the planet. After opposition on September 21 events occur to the east of the planet. In general eclipses will take place while satellites are close to Jupiter's limb during the month.

All these events can be observed through a small telescope. Note that when Jupiter is viewed through an undriven telescope its image will drift to the west. This enables the west side of the planet to be determined.

In the case of disappearances into eclipse (EcD) the satellite is likely to be visible as it fades for a minute or two after the predicted time. For reappearances (EcR) the satellite will start to emerge a minute or two before the predicted time.

At present the north pole of Jupiter is tilted slightly towards the Sun. As a result of the slight tilt eclipses and occultations appear to take place to the north of the planets equator, especially noticeable for the outer two satellites. Transits and shadow transits will cross the planet south of the equator. From New Zealand Jupiter's north pole is the lower pole of the planet.

Table of Galilean Satellite events visible from New Zealand for September 2010

The table shows the times, in UT, of events visible from New Zealand for September. To convert times to NZST before the start of NZDT on the 26th: for times greater than 12 hours UT, add 1 to the date and subtract 12 hours. Thus on September 2, 12:27 UT is 0:27 am NZST on September 3 and 16:13 UT is 4:13 am. For time less than 12 hours UT, take the time shown as pm NZST. Thus 08:26 on September 4 is simply 8:26 pm on September 4.
After NZDT starts on the morning of September 26, it is necessary to add 1 to the date for times after 11 hours UT and subtract 11 hours. So on September 26, 16:00 UT is 5:00am NZDT on September 27. Before 11 hours add 1 to the hours to get the time, pm, NZDT. So September 27 at 09:22 UT is 10:22pm NZDT.

Times of events are adapted from those given by Dave Herald's OCCULT 4 program.

Explanation:
Satellites: 1 = Io, 2 = Europa, 3 = Ganymede, 4 = Callisto.
EcD = Eclipse disappearance, EcR = Eclipse reappearance
OcD = Occultation disappearance, OcR = Occultation reappearance
TrI = Transit Ingress (start), TrE = Transit Egress (end)
ShI = Shadow transit start, ShE = Shadow Transit end.

Date Time UT,  Event Time UT,  Event Time UT,  Event Time UT,  Event
September 2 12:27, 2 EcD 16:13, 2 OcR    
September 3 15:54, 1 ShI 16:22, 1 TrI 18:09, 1 ShE  
September 4 08:26, 2 TrI 10:17, 2 ShE 11:08, 2 TrE 13:13, 1 EcD
   Sep 4 cont 15:54, 1 OcR      
September 5 10:22, 1 ShI 10:48, 1 TrI 12:38, 1 ShE 13:02, 1 TrE
September 6 07:42, 1 EcD 10:20, 1 OcR    
September 7 07:28, 1 TrE 09:45, 3 EcD 14:12, 3 OcR  
September 9 15:05, 2 EcD      
September 10 17:49, 1 ShI 18:06, 1 TrI    
September 11 10:07, 2 ShI 10:40, 2 TrI 12:53, 2 ShE 13:22, 2 TrE
   Sep 11 cont 15:08, 1 EcD 17:37, 1 OcR    
September 12 12:17, 1 ShI 12:32, 1 TrI 14:33, 1 ShE 14:46, 1 TrE
September 13 07:32, 2 OcR 09:36, 1 EcD 12:03, 1 OcR  
September 14 06:58, 1 TrI 09:02, 1 ShE 09:12, 1 TrE 13:46, 3 EcD
   Sep 14 cont 17:28, 3 OcR      
September 15 06:53, 4 ShI 08:06, 4 ShE    
September 16 17:43, 2 EcD      
September 18 07:00, 3 ShE 07:13, 1 TrE 12:42, 2 ShI 12:53, 2 TrI
   Sep 18 cont 15:28, 2 ShE 15:35, 2 TrE 17:02, 1 EcD  
September 19 14:12, 1 ShI 14:16, 1 TrI 16:28, 1 ShE 16:30, 1 TrE
September 20 07:02, 2 EcD 09:52, 2 OcR 11:31, 1 EcD 13:46, 1 OcR
September 21 08:41, 1 ShI 08:42, 1 TrI 10:56, 1 TrE 10:57, 1 ShE
   Sep 21 cont 17:47, 3 EcD      
September 22 08:14, 1 EcR      
September 23 16:02, 4 EcD 17:20, 4 EcR    
September 25 07:38, 3 TrI 07:57 3 ShI 10:30, 3 TrE 11:02, 3 ShE
   Sep 25 cont 15:06, 2 TrI 15:18, 2 ShI    
September 26 16:00, 1 TrI 16:07, 1 ShI    
September 27 09:22, 2 OcD 12:28, 2 EcR 13:16, 1 OcD 15:40, 1 EcR
September 28 10:26, 1 TrI 10:36, 1 ShI 12:40, 1 TrE 12:52, 1 ShE
September 29 07:20, 2 ShE 07:42, 1 OcD 10:09, 1 EcR  
September 30 07:06, 1 TrE 07:21, 1 ShE    

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