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Sunday 24th May, from 7:30pm BST, 200p F/5, EQ3-2, diy Onstep Goto.
I've enjoyed watching Venus wane to a thinner & thinner crescent recently, but have never observed Mercury. Having the 2 planets & the Moon only a few degrees apart this week was an opportunity not to be missed. But the gap between the trees & the hill to my West is only about 1 "fist" wide - maybe 40 minutes of observing time. And the late sunset time means Venus would have moved behind the hill before becoming naked-eye visible.
I don't have a permanent setup & can't see Polaris from my patio so I observe from a very rough "polar alignment" & have marked the tripod leg positions on the patio so I don't need to Polar, or Star align every session.
So, having made sure to "Park" the scope at the end of the previous night's session I could just plonk the setup on the marks, "Unpark", "Goto Venus" & lo and behold a tiny crescent Venus appeared about 1 degree from the centre of the the 9x50 Finder in a sky that was clear of cloud but still pure white from the solar glow ! Isn't Goto wonderful ?
Venus was such a beautiful thin 4% crescent with "horns" stretching to the meridian. At first it was shimmering but that must have been a heat plume because a tiny tweak of the focus steadied the image. The seeing was surprisingly good for the low altitude. I enjoyed the view at up to X250 (4mm TMB), before a Goto to Mercury.
Mercury was not visible in the Finder but was a tiny dot in the 32mm Plossl. At higher powers I saw it as a 45% crescent. I know it was about 62% illuminated so the sky must have been too bright for me to see its full extent. I don't claim to have seen any detail - the brightness just reduced steadily from the limb towards the terminator.
I still couldn't see the Moon naked eye so did another Goto & looked in the Finder. Nothing ! But the bright sky must have been fooling my eye because when I forced myself to focus at infinity it popped in sight. The visible crescent was about half the thickness of a crosshair ! In a 20mm Plossl I could see about 6 medium sized faint, ghostly craters along the limb of a 4% crescent.
So in about half an hour I had my first sight of Mercury, & seen my thinnest crescents of Venus & Luna. Isn't this hobby fantastic ? 😀
Hi, i just wanna mention that i have started a youtube channel a couple of months ago.
My main focus is to explain how all gear works, collimation, all kind of software that I use etc.
Feel free to take a look and i am more than eager to listen to what i can do better to improve my videos, and also tips on what to cover in the upcoming videos
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 ...
We are running a session at my local society on transits and occultations. One station will focus on exoplanet transits, and we'd like to build a very simple model to demonstrate this. We have a star (light source) and an orbiting "planet" but I need to work out how to detect the changes in light intensity and display this on a laptop, like a classical transit photometry trace below (taken from https://heasarc.gsfc.nasa.gov/docs/tess/primary-science.html).
Is there a way to take a feed from a DSLR through the USB output to do this, else I could get an adapter for my ZWO and put an EOS lens on the front of that. I really do want a light intensity vs time trace in real time on the laptop. This model will be run in a darkened room.
Thanks for any comments.