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Just bagged 10 minutes between the clouds and got to see the Mercury shadow transit!
Its so long since I used the Lunt that I took a few seconds to get back into the groove of tuning the double stack and letting some air into the tuner as it was flat.
Not much else on the disc - 3 x sets of proms, 3 tiny filaments, saw one small bright flux patch briefly.
But the Mercury shadow was nice and clear and a decent sized patch too.
Just got back inside before it started spotting with rain! Fingers crossed for another clear patch later ...
I recently bought a 2nd hand Lunt 50PT Ha (on a different platform). The vendor said he had only used it a handful of times since buying it and it shipped in the original box. It seems fine, focuses well (although I find the helical focuser a bit of a pain compared to crayfords). But it doesn't show any Ha features on the surface of the Sun!
Long story short, I completely opened up the pressure tuner and found a bizarre thing. Its well greased, there's no detritus (and it doesn't lose pressure). But there was only one O-ring in it?! The tuner itself has grooves for two o-rings and the video on Lunt's website (on how to replace o-rings) shows a tuner with two o-rings when it comes out. And they ship replacements in batches of two.
So I'm guessing that somehow the original scope shipped with only one o-ring fitted? (It wouldn't make sense for the vendor to have removed one?).
I'm hoping that's what it is, b/c then the inability to resolve Ha features may just be insufficient pressure building up? In which case, does anyone know where I can get these replacement o-rings please (Lunt's US website has them but that's only for shipping to the US)?
If it's not that, and the scope is only meant to have one o-ring, any ideas on the problem? The ring & tuner seem well greased.
(EDIT: in the meantime, the next time the sun comes out, I'm going to try moving the current o-ring from the higher groove to the lower groove in case that longer distance from the base is why the pressure isn't building up sufficiently?)
We are hoping to observe the transit in school (Don’t panic - we have done several transits and partial eclipses in the past so we are fine on the safety aspects - thanks). However does anyone know how I can get hold of some links to use in advance of the day that we can use to put some professional feeds up on the large screen tellies we have linked up to the computer systems these days – I am told that links on YouTube are the easiest to handle on the slightly clunky system we have to control them.
My question comes from reminiscing with colleges that my daughter and I had stayed up to watch first contact of the last transit of Venus live from Hawaii before swapping to Mt Wilson. (We were also up before dawn on top of the local hill fort as the sun rose having lugged an old 4” reflector up there.) Of course at the time we were just browsing through the internet not taking good note of sites we were on.
We have a fledgling Astronomical Society at my place of work and we're intending to have some telescopes available for colleagues to view the transit of Mercury in November. While the majority will use appropriate solar filters it would be good to have at least one set up for projection. However, we only have reflectors and Schmitt or Maksutov Cassegrain scopes among the members. I was considering buying a small refractor second hand to use for this but thought I'd ask for advice here first.
Which is the best type of scope to use for projection?
What do we need to look out for (overheating & fire risks for example)?
What is the best umbrella to protect kit from the inevitable deluge on the 11th November? ☔