Tag Archives: moon

AstroBlog 2019, outing #17 – Backyard imaging attempts for the Moon, Saturn and some stars

The Writing Life of a Tadpole
August 13 2019

In my previous posts, I had the same three targets. The moon is easy (ISO24, 1/250s), although the fuller it gets, the more washed out if I don’t use a filter:

And I can see some single frames of Saturn are worse than others (ISO32, 1/10s):

But I was REALLY setting up so I could play with my camera centring. As I noted in a previous post, the feedback from an online FB group was that my EP wasn’t centred. So I wanted to ensure 100% that I was centred last night. For one of my stars off to the side, defocused into a doughnut, I was clearly NOT centred (screengrab of Night Cap below):

But I moved the stars around a bit in the EP and managed to get something a little more balanced:

And then BAM, I got this:

Only minor differences in positioning, no difference in my centring over the EP. The beauty of the adapter I’m using is that it centres on its own (the physical connectors are aligned so they ALWAYS centre properly). Which left me REALLY confused. Does that mean I’m only centred and aligned for that specific spot on the screen? Not out to the edges? I went back to focus, found a single star, tried ISO10K for a short 2s, and got this, a nice little dot:

I tried Altair, and dropped ISO to 8K while keeping it at 2s:

Under the heading of weird, I dropped exposure to 1/2s, and got this, with a few extra stars poking through more than they did above:

When I increased to 4s, I got some more stars, which makes sense:

I tried another EP, the Hyperion 36mm, and tested my “setup” with a screengrab:

And again, I could find at least one spot that was dead on.

But ISO 10K and a 4s burst? No additional stars. WTF?

So I did the same settings again. And got this:

More stars, different sized star capturing. I bopped over to a small open cluster, dropped duration to a single second, and ISO to 8K. And got more stars, but mixed pinpoint and not. Sigh.

Just for fun, I was wondering what would happen if I did a video of the cluster and stacked it. Nothing that useful, apparently.

A second video did NOT stack well at all.

I also tried a video of (I think) Altair again. Then converted in PIPP and stacked in AutoStakkert. After the one above, I wasn’t expecting much. But it actually seemed to work, while limiting it to I think the best 10%:

The little stars aren’t pinpoint, but overall, the image is promising I think. Now I just have to start figuring out why one works and the other one doesn’t.

Signature, clear skies
Share

AstroBlog 2019, outing #16a – Backyard imaging attempts for the moon

The Writing Life of a Tadpole
August 12 2019

I have blogged previously that I’ve set a goal for myself of figuring out how to work my iPhone to take pics through the telescope, and I’ve had earlier success for the moon. But to be honest? The moon is dead simple. If I set an ISO between 24 and 50, and play with my duration to be between 1/100th of a second to 1/300th of a second, and it’s relatively in focus, I can get “something”. The more moon there is showing, the brighter it is, and it’s easy to get washed out without a filter, but any of the setup problems virtually disappear when it’s the moon.

On Saturday, August 10th, I stuck my head out of my back door, saw the moon and went ahead and set up. As always, I’m setting up a Celestron NexStar 8SE, stock alt-azimuth mount, and an iPhone XS Max phone running Night Cap software. The only “variables” that were up for the night were the new Phone Skope phone adapter that allows you to mount the phone over the eyepiece and my choice of eyepiece, which tonight was a 25mm Celestron Plossl that comes with the 8SE scope. My night was divided into three “target zones” — the moon (below), planets (next blog post) and stars (the blog post after that).

With stock f/1.8 settings, I used ISO 24 and 1/300s to get me this:

That is a straight single frame, no tweaking or adjustment of anything other than flipping it horizontally to correct for my diagonal giving me the mirror image by default. Like I said above, the moon is dead easy.

I tried stacking in Nebulosity, and I have little experience using it on the moon. I made it worse, stacking all the images:

I thought it was my choice of stacking technique, so I went a little more complicated to remove the possibility of rotational errors, and, well, it was even WORSE:

I really don’t need to stack it, the single frames are more than sufficient for now. Post-processing will come, but it’s farther down my priority list.

At the top of the big image, I zoomed in a bit to see the top ridge above Mare Imbrium. It is called Montes Jura, and the little alcove below it is Sinus Iridum. The closer photo is below:

The big crater is Copernicus and the little mountain area above it a bit to the left is Montes Carpalus. A third of the way from the bottom of the picture to Copernicus is the landing sites of Apollo 12 (Nov 19, 1969) and Apollo 14 (Feb 5, 1971).

Zoomed in even further on Copernicus, starting to have some issues with focus:

The crater is about 93km across, and about 3.8 km deep (from the top of the rim). The little mountains in the centre are 800m tall, the result of rock “rebounding” upwards after the impact crater was formed by a meteor hitting it.

I then decided to go to the bottom of the moon, and see what I could get of the rocky/bumpy portion. About one-third of the way from the left side, and one-third from the bottom, just below the darker area, there is a prominent crater with a dot in the centre. The crater itself is my favourite, Tycho, and I have no real idea why. Maybe I just like the name of it, but mostly I think it is because it is one of the first ones I ever imaged and subsequently learned its name. Tycho is near the size of Copernicus, 85 km across, but a smidge deeper (at 4 km, or 4.7 km if you go to the top of the ridge). The central mountain is 2 km tall.

The two craters are quite different in age though — Copernicus is about 800 million years old, while Tycho is a young buck, only 100 million years ago. Or, as the joke goes, 800 million and 100 million, plus two days, as I took the photo two days ago.

Signature, clear skies
Share

AstroBlog 2019, outing #11 – Star party in Carp…

The Writing Life of a Tadpole
August 8 2019

The night of Saturday, July 27th was our attempt at our monthly star party in Carp, suitable for public stargazing. The forecast at mid-day was pretty iffy, but I crowd-sourced some other views, and we said “GO!” hoping for the best. What we got was considerably below “best”.

At 9:00 p.m., we were about 70% clouded out to the North and West. To the South, we had some windows between a few clouds, enough for Saturn to put in an appearance. Oddly, it showed up before Jupiter just because Jupiter was playing hide-and-seek still. A new member needed help setting up a Dobsonian, and I got him going just in time for Saturn to appear and for him to try it. He nailed it first try and by all accounts, seemed pretty happy overall for the night.

I was surprised — sure, we called a “GO” for the night, but generally, most people who are coming look up and change their minds if the weather is lousy. Not last night — we had almost 150 people for the night! I was really surprised. A lot of newcomers, some who had never looked through a scope before, and even if they had, many had never seen Saturn before. So from their perspective, the night was a hit. For the experienced astronomer, not so much.

Saturn and Jupiter went in and out for the night. A friend hosting an event about 30 minutes north of us across the river in Quebec was completely socked-in and had to close up shop. A couple of times we had NOTHING going on, just waiting for things to come back out. You know the weather is bad when you set up on Arcturus and people are impressed to see that.

For me, though, the highlight of the night was meeting a young woman named Izabella. About 16, I think, and interested in the stars. She had dragged her mother out and had never looked through a scope before. She was very interested in the stars, even if I couldn’t show her Vega (it was practically at the zenith, which is a poor position on my SCT to hit without becoming a contortionist or having perfect alignment). Even as we got close, it suddenly clouded in and I could see nothing. Sigh. However, we hung out for over an hour, and I let her try working the scope to find Arcturus and Mizar, which she did well.

Earlier in the night, when I was setting out to go, I did a dance with my son as to whether he wanted to come. He could only stay for about 90 minutes if he went, and there was no guarantee there would be breaks in the clouds enough to see. In the end, he would have seen SOME stuff, but not worth it to have gone, so I’m glad he stayed home. I want his first real star party to have LOTS of targets for him to see. We may try again on Friday. Fingers crossed.

Signature, clear skies
Share

AstroBlog 2019.009.1 – Viewing through a lousy scope

The Writing Life of a Tadpole
July 21 2019

Almost everyone who is into astronomy as an adult has either experienced themselves or heard the stories about kids getting gifts of department store-quality telescopes and being so frustrated with the scope, and their inability to find anything, they end up giving up on the hobby. Some find their way back as adults, some don’t.

The destruction of interest haunts all amateur astronomers, we want others to share our excitement, and it is the principal driver between so many amateurs setting up their scopes to share the experience with anyone and everyone. Star parties, Scouts and Girl Guides, classrooms, corners, parking lots…we’ll set up almost anywhere.

There are fewer department stores around these days, but that doesn’t mean the crappy scopes are gone. Some even have semi-trustworthy names. National Geographic has licensed their name to a number of low-end toys, not really functional scopes, and you can frequently find them being sold off on FB or Kijiji for $20 or less, evidence of abandoned dreams.

When I was a kid, I was interested in the stars, and my parents got me something even worse — a hand-held telescope for land viewing. Like most of the parents buying them, they didn’t know any better. Like binoculars, only just a single lens. It was almost impossible to hold it steady while looking through it at my young age, and I know I never even tried to look at the moon unless it was a full moon (I never saw terminator stuff). I vaguely remember using it and binoculars to look at stars, but one night with no luck was enough to abandon that. No tripod, no eyepieces, just a single telescope with adjustable length. A horrible design for anyone wanting to look at the stars. By contrast, the cheap ones like National Geographic are actually functional designs — basic reflectors on cheap alt-az tripods.

And it got me thinking. The crappy scopes are terrible for beginners because they are almost impossible to control and use well, and they jump around. But what if you tried one as an experienced astronomer? Would they still be completely useless? Someone had one on FB Marketplace nearby for $20 and I thought I would give it a try for the experience.

But you know what? It wasn’t completely terrible. I know, I’m surprised too. It worked 1000% better than I thought it would.

It was all plastic, a bad sign to start. Lots of little parts to screw in, and no instructions. I didn’t really need any, but there was one part I had to look at the box to see in the picture what it looked like officially (mostly to get the right angle). A spotter goes on top, and it was a bit tricky to get the knurled screws to line up, but not much different than a real scope. I was a bit surprised to see that it comes with three little eyepieces — 20mm, 12.5mm, and 7mm. Plus some form of a 3x barlow (multiplier/magnifier) but I’m not even sure how it fits into anything…the barlow is REALLY long.

My first target of the night was a very bright Jupiter. The focus knob is a wheel that moves the eyepiece closer and farther away in the tube (shortening and lengthening the tube) which is always a bad design — it means every little twitch shakes the scope. Nevertheless, I did get a white disc for Jupiter. No bands, no details, but a solid white disc.

Saturn was a pleasant surprise. I could see the rings. Sure, I couldn’t split them or anything, but it was clearly Saturn. With a $20 plastic scope, no less.

The moon came up and although it was full, the resolution was fine. A bit too bright, and no way to put in a filter for the odd-sized EPs, but if it hadn’t been full, I would have seen details on the terminator line.

I was thinking I would use it, maybe take it apart to see the guts, and then toss the parts. Yet it was usable, mildly so. Don’t get me wrong, it is absolute junk, and any beginner would be ready to pitch it in frustration. But as a near-free option to leave somewhere for easy moon viewings? I don’t know if I will take it apart after all. I’d like to try it on a properly stable tripod, maybe my camera one, and see if it would “hold still” to look at the moon.

As I said, I saw Jupiter (sort of), Saturn’s rings, and the full moon. It probably wasn’t as good as simple binoculars, but again, I was surprised it didn’t completely suck, at least not for someone who generally knew what they were doing before they started.

Signature, clear skies
Share

AstroBlog 2019.005.2 – Imaging the Moon

The Writing Life of a Tadpole
July 5 2019

Continuing my imaging attempts on June 11th, I did some more of the moon from my backyard. All of the images are single frames with the iPhone, only flipped horizontally (I have a diagonal so have to flip the image to get it “right” looking). For all photos, I’m using:

  • Celestron NexStar 8SE
  • 25mm Plossl
  • iPhone XS Max, f/1.8 lens
  • Night Cap software

Settings of ISO 24 and 1/250s were the sweet spot for me for the night given the brightness of the moon. I did a series of single frames, and this was the best:

Then, because I had a series, I tried stacking them in various software packages. This was the best one I got, but way too pale, I will need to work on that if I want to get true 3D depth in some of the images.

For fun, I used the zoom feature on the iPhone just to see what I would get, and I took three shots, capturing the craters Plato, Copernicus and Tycho. From the original, I even played with creating a map and then the three breakout images (note that in the map, the three images are not crops but actual full images that follow):

Plato, left of centre:

Copernicus in the bottom right:

And Tycho in the top centre (with the small round mountain in the centre):

My workflow seems to be working well for the moon shots at least, so I should be able to do some documenting of various features for different days of the lunar cycle. It might take a few months, I suppose but it should be fun.

Signature, clear skies
Share