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Events of the Galilean Satellites for August 2008


Table of Events visible from New Zealand for August 2008.

Events of Jupiter's Galilean Satellites

Eclipses, occultations, transits and shadow transit of all four Galilean satellites will be occurring at regular intervals during August. A table of events visible during the month visible 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. After opposition, as in August 2008, they occur to the east of the planet.

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 south pole of Jupiter is tilted slightly towards the Sun so that eclipses and occultations appear to take place to the south of Jupiter's equator. Transits and shadow events appear to take place a little north of Jupiter's 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 August 2008

The table shows the times (in UT) of events visible from New Zealand for August. To convert from UT to NZST: if the time is less that 12 hours, add 12 to the hours, or just treat the times as being pm. Thus August 1 at 10:23 UT is 22.23 (10.23 pm) NZST. If the time is 12 hours or more the event occurs after midnight, so add one to the date and subtract 12 from the hours to give NZST am. Thus August 1 at 15:55 UT, is August 2 3:55 am NZST.

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
August 1 10:23, 3 OcD 15:55, 3 EcR    
August 2 16:42, 1 OcD      
August 3 13:59, 1 TrI 14:35, 1 ShI 16:16, 1 TrE 16:52, 1 ShE
August 4 11:08, 1 OcD 14:02, 1 EcR 15:13, 2 TrI 16:27, 2 ShI
    August 4 cont. 17:56, 2 TrE      
August 5 08:26, 1 TrI 08:28, 4 ShI 09:04, 1 ShI 10:42, 1 TrE
    August 5 cont. 11:21, 1 ShE 12:16, 4 ShE    
August 6 08:31, 1 EcR 10:05, 2 OcD 14:13, 2 EcR  
August 8 07:05, 2 TrE 08:29, 2 ShE 13:47, 3 OcD  
August 10 15:45, 1 TrI 16:30, 1 ShI    
August 11 12:54, 1 OcD 15:57, 1 EcR 17:30, 2 TrI  
August 12 06:38, 3 ShI 06:43, 3 TrE 09:56, 3 ShE 10:12, 1 TrI
    August 12 cont. 10:59, 1 ShI 12:29, 1 TrE 13:16, 1 ShE  
August 13 07:21, 1 OcD 10:25, 1 EcR 11:41, 4 OcD 12:25, 2 OcD
    August 13 cont. 15:21, 4 OcR 16:51, 2 EcR    
August 14 06:55, 1 TrE 07:45, 1 ShE    
August 15 06:40, 2 TrI 08:20, 2 ShI 09:24, 2 TrE 11:04, 2 ShE
    August 15 cont. 17:13, 3 OcD      
August 18 14:41, 1 OcD      
August 19 06:58, 3 TrI 10:12, 3 TrE 10:39, 3 ShI 12:00, 1 TrI
    August 19 cont. 12:54, 1 ShI 13:57, 3 ShE 14:16, 1 TrE 15:11, 1 ShE
August 20 09:08, 1 OcD 12:20, 1 EcR 14:47, 2 OcD  
August 21 06:27, 1 TrI 07:23, 1 ShI 08:43, 1 TrE 09:40, 1 ShE
August 22 06:49, 1 EcR 09:01, 2 TrI 10:55, 2 ShI 11:45, 2 TrE
    August 22 cont. 13:40, 2 ShE      
August 24 08:47, 2 EcR      
August 25 16:29, 1 OcD      
August 26 10:31, 3 TrI 13:44, 3 TrE 13:48, 1 TrI 14:39, 3 ShI
    August 26 cont. 14:50, 1 ShI 16:05, 1 TrE    
August 27 10:56, 1 OcD 14:15, 1 EcR    
August 28 08:16, 1 TrI 09:19, 1 ShI 10:32, 1 TrE 11:35, 1 ShE
August 29 08:44, 1 EcR 11:24, 2 TrI 13:31, 2 ShI 14:08, 2 TrE
    August 29 cont. 16:16, 2 ShE      
August 30 06:56, 4 OcR 07:57, 3 EcR 13:18, 4 EcD  
August 31 11:24, 2 EcR      

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