11th mag. star visibility? Mimi Occultation 7 May, Ireland

Actually, I think it could be done. I was playing around with AstroPlanner's Limiting Stellar Magnitude, and with an 8" SCT in not-great seeing (2.5 arc-seconds) and not-great transparency (0.7 extinction coefficient), you can still reach Mag 11 at 30° altitude with a naked-eye-zenith-limit of 1.

So the question is, do we have NELM 1 or better during twilight? I think so; I can certainly see Arcturus when it's still quite bright outside.

(And with Dave's scope you can get there with 4 arc-second seeing and 0.9 extinction. )

-- Jeff.

well at 10pm last night I was trying to get in M3 and it was underwhelming as alot of the fainter stars were not there, lost in the blue sky, having said that the sky was not perfectly transparent, but then again is it ever ?

we'll go ahead and give it a try by all means, but I don't think it'll be easy.

Dave --

M3 has a V(tip) of 12.7, so the brighter stars in it are still a good bit dimmer than 11. (See: www.ngcic.org/papers/gcdata.htm .)

But let us know how it goes; I'm quite curious now.

-- Jeff.

ouch bad news.
Sun will be only 2 deg below the horizon. Looks impossible.

Vagelis,
I think it is simply going to come down to seeing conditions based on an observer's location. Some of Ireland's south and west coast enjoys almost-to-the-horizon clarity at times. However, the more we go into summer, Irish skies become more hazy regardless. Ireland seems to experience many micro climates across this relatively small island.


That about sums things up. Also Ireland does not have a "CLIMATE" as such. We can NEVER tell from year to year what the weather for the same months will be. What we have here is "weather"...........................May last year may have been wet and cold..................and May this year may be warm and sunny.

Irish weather really is too fickle to be able to say on any given date what conditionjs may be like.

It's pretty damn frustrating for us stargazers.

For us........................it really is a case of "Take it as it comes".

ouch bad news.
Sun will be only 2 deg below the horizon. Looks impossible.

That sums it up then for us here Vagelis, sorry to disappoint you!