From: TerryMoselat

Date: 17 July 2009 21:22:36 BST

Subject: Eclipse, Lecture at Tara, Jupiter occultation


Hi all,


1. A total eclipse of the Sun on July 22 will only be visible in the Far East and Pacific area. I'm off tomorrow with a bunch of (mainly) Irish hopefuls to Shanghai to see it, so wish us luck. Back on 30 July. I won't be reading any emails until then.


2. 22 July:  The final lecture in the IYA 2009 series at the Tara Visitor Centre, just off the N3, south of Navan, will be at 8 p.m. Looking at the future for space telescopes, i.e. mainly the future for the HST, and its successor the James Webb Space Telescope, it will be given by Dr Denise Coffey from DIAS. Admission is free, but seating is limited, so better to get there by 19.50 at the latest.


3. There will be quite a rare event on 3 August, when Jupiter will occult the 6th magnitude star 45 Capricornii, at about 23.50 BST (the exact time depends on your location). The star is one of the brightest that Jupiter will ever occult during our lifetimes, so this will be interesting to watch, and video. The star will be a bit fainter than Callisto, the faintest of the 4 Galilean moons. It will disappear behind the Southern limb of the planet, at about the position of the SSTB (South South Temperate Belt). Jupiter will be only 11 days before opposition, so the phase effect will be negligible: in other words the star will disappear behind the illuminated edge of the disc, but of course there will be considerable limb darkening, as the Sun will be setting on Jupiter's horizon at this point.

   And of course Jupiter will be retrograding as it approaches Opposition, so the star will be occulted on the planet's WEST limb, and will reappear at the EAST limb.

   The 4 Galilean moons will also be visible, lying in the plane of Jupiter's equator, so there's no chance of mistaking them for the star. Closest in to the planet on the same side as the star will be Europa, which will actually go into eclipse in Jupiter's shadow at 00.47 (on the 4th), and then Io. Ganymede and Callisto will be much further out, on the opposite side of Jupiter. The event will last until about 01.50, again depending on your location. More details when I get back from China, but you might want to make a note of the event now.


Clear skies,


Terry Moseley