Telescope Reviews: Obs rep Ganymede EcD 082908 next Io EcR 090608

Observed an occasional eclipse disappear event (EcD) for the Jovian Moon Ganymede 2008-08-30 at 4:36 to 4:40 UTC (2008-08-29 10:36 to 10:40 MDT) from SLC, Utah (111 W, 40N). A small 70mm refractor on an alt-az mount was used. This is an EcD event on p. 218-219 of the 2008 RASC Observers Guide.

Unlike the 8-14 Io eclipse reappear event, the duration over which Ganymede disappeared lasted about 3 minutes and had much for a distinct gradient as compared to the 8/14 Io reappear event. Ganymede could be tracked with averted vision up to 4:42 UCT. As expected, the concurrent Io shadow transit was not resolvable in this small refractor.

I attributed the difference in the apparent light curve to Ganymede's relative larger size and distance from Jupiter.

Details on other EcR events visible from the Intermountain West and Pacific zones through Nov. 1, 2008 can be found at my note page at:

http://members.csolutions.net/fisherka/astronote/tours/JMEcl2008/JupEclSP.html

Next event is an Io ECR at 9/7/2008 5:08 UTC or 9/6/2008 23:08 MDT.

- Kurt