[Tropo-Bob (Bob)]

I observed Ganymede eclipse disappearance on 10th May and Europa reappearance out of eclipse on 11th May. Both of these events happened very close to Jupiter's limb, as would be expected since Jupiter was in Opposition on 9th May.

Ganymede.
I followed Ganymede's disappearance with 2 scopes. I commence observing with a Tele Vue Ranger using 68x on an altz mount. However, I became nervous about having sufficient light grasp and the possible difficuties of observing the event, so I also setup a 5" SCT with aprox 100x on an EQ5 mount.

Observing the dimming of Ganymede was difficult because of its closeness to Jupiter's limb. It was a bit like trying to resolve an equal double star. I kept swapping from scope to scope. The view was cleaner through the Ranger with with a tiny, sharp point appearing next to the limb. It was a little easier to see with the SCT because of the extra magnification and light grasp, even with the trade-off of the view being less sharp. Ultimately, it did not make much difference. Ganymede was visible in both scopes at 21.21 and disappeared in both scopes at 21.22.

Ganymede disappeared close to Jupiter's south pole. For a while, I actually wondered whether it would not pass behind Jupiter's disc, but only disappear into the shadow.


Europa
I used my new (but secondhand) Vixen ED 81mm to view Europa's reappearance out of eclipse. Two evenings prior, I had view Europa transit across Jupiter below the northern polar region. Thinking of how Jupiter's plane is currently offset to us, I then deduced that it would reappear on the same side below the southern polar region. I also wondered if I would see the moon brightening, or whether it would just appear close to Jupiter's bright limb.

Using 125x, Europa just appeared when at or near full brightness, but at least it appeared where expected.


Future events:
Tonight (12/5): Io has an occultation at 22.57, reappearing tomorrow at 1.11.
Tomorrow (13/5): Io has transit and shadow events from 20.16 to 22.32.