2005-08-28

Built the Solarscope

Got the chance to assemble the Solarscope this afternoon. Although I didn't time myself I'd say it took less than 20 minutes to put together. It was pretty easy to do. There are two points where you do need to pay attention as getting it wrong appeared to be a you-can't-fix-it situation. The first is when you place the mirror into its holder (you need to make sure you put it in the right way round) and the second is when you fit the outer holder for the lens on the end of the telescope (it's got some sort of ratchet thing on it that means you can't easily unscrew it again).


It was cloudy all morning and still was as I assembled the 'scope. However, not long after I'd finished, the skies cleared. I took it outside, lined it up on the Sun (very easy to do) and there it was. Focusing took a little time to sort out first off as I had to adjust how the telescope itself sat (the orange thing you can see in the pictures) but once I'd found the right spot final focusing (by turning the screw on the mirror holder) was very simple.

Four groups of sunspots were easily visible. What I need to do now is figure out a useful method of recording what I see. My only complaint about using the 'scope at the moment is that the part of the inside of the housing that you project on to — which is white — has a number of spots on it. When you're first looking it's sort of hard to tell what's really a sunspot and what's a mark on the card. Moving the image clears up that confusion but it's a shame that it's an issue.

2005-08-26

"Sun, sun, sun, here it comes"


The Solarscope arrived this morning. Hopefully I'll get the chance to put it together this evening or over the weekend.

2005-08-25

Here Comes the Sun

On the 3rd of October there's an annular solar eclipse (which, from where I live, will be a partial eclipse). Mostly because of this and partly because I wouldn't mind getting back into some solar observing I've ordered a Solarscope from Green Witch.

While I could probably have done the usual thing of projecting with a binocular or telescope (or even with a pinhole projector) I quite like the idea of having a dedicated tool that's easy to set up.

I'll write more about it when I get my hands on it.

Update (14:19 BST): Just had shipping confirmation from Green Witch. All being well it should turn up tomorrow.

2005-08-23

New Drawing Template

Not too long back I started making an effort to sketch what I was seeing when observing. The point of the sketches wasn't really to produce any sort of work of art &mdash it was more about trying to get me to slow down at the eyepiece and actually observe what I was looking at. Also, if I was unsure of what I was looking at, a sketch was a good way of recording the view for later checking (as has happened here and here).

Because I used a lined notebook for keeping notes I needed to provide something blank on which to draw so, when I started out, I simply created an A4 template in the drawing program in OpenOffice, printed a couple of sheets out and cut them up. When I've made a drawing I simply stick it into the appropriate place in my notebook. The template was nothing more than six circles on an A4 sheet of paper.

However, having seen the efforts of Jeff Stevens this morning I was inspired to make something that looked a little nicer and which would be easier to scan and crop. So, again, using the drawing tool in OpenOffice I've now created a new set of templates. It'll be interesting to try them out and see how I get on with them.

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2005-08-16

Fear of Mirrors III: Return to Observing

Last night saw a reasonably clear sky so I used the laser collimator to collimate the 'scope as best as I could and then dragged it outside for a couple or so hours under the stars.

2005-08-13

Fear of Mirrors II: When Mirrors Attack

The weather was still horrible right up until this evening so I finally decided to have a go at center-spotting the mirror with a ring-binder reinforcement ring. I carefully made my template. I cut out a circle in the middle of it that was just the right size for the reinforcement ring to pass through. I cleared a workarea in the kitchen and laid everything out.

On the advice of someone else I even went to the trouble of marking up each of the screws and their position on the 'scope so that I could put everything back where I found it.

Then I picked up the screwdriver.

I started to undo the first screw. With just a handful of turns it become really loose but didn't seem to want to come out. Few more turns, still loose, but not coming out. I found this odd, considered giving up there and then and then decided to tighten it up again just to check that I wasn't doing anything stupid. It tightened up fine. So, I started to undo it again and, after a lot of turns it finally came out.

Started on the second screw. Same "loose but not coming out" thing was happening. So, wanting to be sure I still wasn't doing something stupid, I did it up, popped the end off the scope and shined a light down it to see what was happening.

Horror!

At the bottom of the scope was a nut just lying there doing nothing useful! It was then that I realised that I was undoing totally the wrong screws. There are four screws around the outside of the bottom of the 'scope and I'd got it into my head that it was those that I should be undoing. Wrong screws! I should have been undoing the three locking screws on the bottom of the 'scope.

After a few moments of bad language and resisting the urge to bang my head against the nearest wall I wandered off to have a small break and calm down.

I then carefully tilt the 'scope up and let the screw run out into my hand.

So, next, I undo the right screws and out pops the mirror with no fuss or bother at all. I fix the wrong screw back in place and then offer the template up to the mirror. Thankfully it seemed to be a perfect fit. The problem now was that my hands were shaking so much that I couldn't get it fully in position and wouldn't have got the reinforcement ring in place no matter how hard I tried.

Another break.

This time I manage to get the template over the mirror with little fuss and drop the ring into position. After measuring it looks like I've probably managed to get it between 1 and 2mm off center but I'm assured that this shouldn't really matter too much.

After putting the 'scope back together (thankfully a reasonably hassle-free procedure) I found that the alignment of the optics was totally off so I'm then forced to do my first ever round of collimation. Now I see why so many people (myself included) are put off doing it. I undid the locking screws and then started to mess with the adjustment screws to see what effect they'd have and started to get a feel for it pretty quickly. Once I was happy that everything was roughly lined up I did the locking screws up again and this threw it right out again. So, what followed was a period of messing with locking screws and adjustment screws until I finally had everything locked into place and pretty well lined up.

So, as best as I can tell at the moment, I'm now back with a working telescope that's about has badly collimated as it was before — perhaps slightly better — but with a center-spot to help with using a laser collimator and also that helps with collimating by eye. And, of course, I'm also left with an experience that sort of confirms that my fear of going near a telescope with a screwdriver wasn't that irrational after all.

To top it all off, when I stuck my head outside about half an hour ago, the rain had stopped and the clouds had cleared and it looks like it's heading for a nice clear night. I can't decide at the moment if I should drag the 'scope out and see if it still actually works or if I should just sit in a chair and try and catch some late Persieds.

Still, it seems like it's been a useful night after all. Lessons have been learnt and experience gained.

2005-08-12

Wrong Sort of Showers

It was bound to happen wasn't it? For most of this week it's been pretty fine during the day and then cloudy after dark. Last night it was chucking it down, lightning and all.

Tonight is the best night for the Perseids and, sure enough, the sun is shining at the moment but the last forcast I saw for our area suggested that tonight will see cloud and showers. Annoyingly the wrong sort of showers.

2005-08-10

Fear of Mirrors

It's about time I collimated my telescope (actually, it's been "about time" ever since I got it back in April this year). One thing that has been putting me off is an irrational fear I have of taking apart things that seem to work. I've never really been that practical a person and always seem to find some way of breaking (or convincing myself that I am breaking) anything I try and fix.

The telescope is a 5.1" Newtonian Reflector (a Sky-Watcher Explorer 130M to be precise). I've already had a little go at collimation using the film canister method and that almost ended in disaster when, as I tried to adjust the secondary mirror, it came away from the spider and almost fell into the tube. Normally something like that would put me off for life.

However, having only had passable results with viewing Jupiter and Saturn and with Mars coming around for another close pass I've decided that I should make a point of tuning the 'scope and, with this in mind, I've purchased a laser collimator to help make the job a little easier.

Problem is, to get the best out of it, I really need to center-spot the primary (the mirror didn't come with one marked). This is where the irrational fear really sets in. The idea of actually taking a screwdriver to my 'scope and removing the primary mirror fills me with dread. The rational part of me knows that it isn't going to be a problem; the part of me that paid a good few quid for the 'scope fears that I'm going to horribly muck it up.

I'm not sure yet when I'm going to get the time to do this, hopefully I'll do it in the next few days. If that happens you can expect to see a post that either says how easy it was and how stupid I've been for putting it off or there'll be a post that involves lots of hand-wringing.

2005-08-09

Good Bad Astronomer

The Bad Astronomer (actually, he's rather good) has an interesting article in his weblog about Intelligent Design.

2005-08-08

The Perseids

Time for the Perseids again. Given that this is the first "major" shower available since I started to get back into observational astronomy I've decided to try and make a good effort to observe it. I'm not totally sure how I'm going to approach it yet but I am gathering together a few ideas for what to do.

While the maximum isn't that favourable for me it should, weather permitting, be a reasonable show.

Equipment and stuff I've got or will need to put together:


  • Sun lounger. Borrowed one. Might as well be nice and comfortable while I'm observing.
  • 10x50 binocular. Got a pair. Useful for looking at any trails left by a meteor.
  • Logbook. Got one, obviously.
  • Sky charts for writing on. I'll make some up this week. The idea is to use a handful of them to keep track of where I see any meteors.
  • Clock set to UTC. Got one, obbiously.

If all goes well I'll see about sending my results to the meteor section of the SPA.