Solar System Sketches: The Lunar X, planets, and a mission critical unaided-eye detection of Jupiter just after sunrise.

 Finally the conditions are starting to favor good seeing, and I've been able to do some high-resolution observing with the FlexTube 250P, primarily involving the Moon. I've also done some interesting things with smaller scopes.

There was a lot of detail here I couldn't hope to capture--I'd have to draw the field circle 2-3 times larger to even fit the detail on the page. I think for lunar features I might abandon sketching field circles, and focus on rendering the specific features I want to focus on at a higher resolution.

What you don't see in the sketch is just how terrible the conditions were. At times, trying to see what I wanted to draw was a grueling task due to the low contrast. The seeing was pretty good for the most part and the Moon was very sharp, but a thick haze filled the sky and it only seemed to get thicker as I went on. The lack of contrast is the main reason I didn't fill up the top quarter or so of the field circle--i just couldn't hold onto those features long enough to do them justice.

The lunar "x" is a weird effect of the shadow play which only occurs for a few hours shortly before the first quarter moon. It is visible even in small telescopes and binoculars as a bright white x shape on the terminator. Not far away is the slightly subtler lunar "v", which I made a separate sketch of as well.

There are so many interesting and weird craters on the Moon. The one on the terminator at the far right of the picture was especially intruiging, a double-crater, one of which was very elliptical in shape, with a stretched-out central peak, and the round component had a very pleasing outer rim structure.

Sketching features on the moon which are not craters is rather difficult, there's all sorts of subtle crinkles and hills and soforth which are interesting to look at but a nightmare to accurately reproduce in low-contrast lighting. There's one region just north (left) of the lunar x which was very poorly defined in the sketch, because it was a very rough region where it was hard to tell what was going on. The low contrast definitely didn't help. It also didn't help that the proportions weren't quite right there, so some features around it are a bit squished together in the sketch.

I had a lot of lunar sketches in my first pandemic-era astronomy log (April 2020 to December 2020)--around June last year I observed and sketched the Moon daily for two weeks, and there were a few other nice sketches here and there. But for some reason my second log (Dec 2020 to present) has very few lunar sketches and no really nice ones. Partly because the seeing hasn't been really good and partly because I haven't felt motivated. Compared to DSO sketching, lunar sketching takes a very long time. Since lunar photography is comparatively easy (it's virtually the only thing you can get genuinely good results out of with a smart phone and a manual mount), I've mostly been doing that.

Still though, I do recommend sketching the Moon and recording what you observe in a log. Even if you don't spend an hour sketching the Moon, even a simple cartoon showing stuff on the terminator or other things you see is going to keep you engaged and thinking about what the geography you're seeing a lot more than taking a photo, or visually observing without a log, would. You don't have to be an artist to make a useful record in your log.

That was a few days ago. Early his morning, I went out with my C90, ST80, and Z130. The results of playing with the C90 and ST80 will have to wait for another post, but they may surprise you. Oh by the way, did I mention? I got a C90. The Z130 is a lovely affordable little telescope which always surprises me by how much it can show. I guess it shouldn't, I mean a 5" should be almost indistinguishable from a 6" without side-by-side comparison, and I know my 6" Dobsonian shows nice images. The most remarkable thing is the Z130 was out of collimation--the focuser drawtube isn't sturdy enough to preserve collimation. I think I could have gotten even sharper images out of it if I were to shim the drawtube and collimate the telescope properly. That's a project I intend to do.

 

Yes, these were originally pencil sketches. Grayscale pencil sketches, with a normal number two pencil on regular white paper. Here's the original: 

This is my first attempt colorizing and heavily processing a planet sketch and I'm pretty happy with the result. If you sit at a comfortable distance from your monitor it looks very similar to how it looks in the telescope.

I used both a 6mm eyepiece (270x) and a 10mm eyepiece (162.5x) while making each sketch, but I listed the 10mm because the 6 rarely showed that much more detail, until after the telescope had fully cooled down. The amount of field of view the planets take up is much larger in the sketch than you would actually see at these powers, I shrunk the field circles for convenience. Sitting at my monitor each field circle takes up 10 degrees of arc, approximately. In reality the apparent field of view was 40 degrees at 162.5x and 66 degrees at 270x.

I brought the Z130 out to my front driveway, the only place I could see Jupiter & Saturn in the morning. Jupiter was spectacularly bright at first, but by the time I'd set up, dawn was well on its way. As I observed, I was mostly waiting for the Z130 to cool down and acclimate to ambient air temperature. The seeing conditions were spectacular, but the Z130 couldn't see how good it was at first.

I knew I wanted to sketch Saturn first, because as it got brighter it'd be the first to fade from visibility. But I ended up waiting long enough that by the time I was done, Jupiter had faded from visibility!

I spent some time trying to recover from this. I put a 32mm Plossl in the focuser for the widest field of view, but the focus point was just a guess. The Sun was now rising, and the sky was now much brighter. I kept trying to search for that little dot. It is possible to see Jupiter during the day, especially at sunrise. It'd have been easier without photochromic/blueblocker glasses which cut out almost a magnitude from my naked eye view, but I can't see without glasses and they're all I've got for now. I tried scanning around where I thought it was in the sky, but the field of view just wasn't wide enough to have a shot at this random approach.

I took my phone out and launched SkEye, a planetarium app which uses the gyroscope and magnetometer to orient itself. I held the phone up to the sky where it said Jupiter was, waited for it to settle, then focused on the space behind my phone, and moved the phone away. Carefully preserving my head angle to the trees and houses and horizon, I moved my head down to the red dot finder. On my way to it, I spotted the faintest hint of a dim white dot. I aligned the red dot finder, looked in the eyepiece... and there it was. By that point, the Sun had risen, which means I've officially (barely) detected Jupiter with the unaided eye during the day.

From there, I was able to work my way up to high power, being very careful not to move the scope and lose Jupiter, and I was able to make a good sketch of Jupiter's cloud banding. The seeing was spectacular at that point, and I was surprised by just how much this scope could show. I could even still see its satellites, just barely.

The coloration in the sketch depicts Jupiter before sunrise, but still during late dawn.

Looking out at the clear, pale-blue dawn sky with thin hazy clouds, just before packing up.