Getting ready for the comets, though May is going to be an exceedingly busy month, unfortunately. The weather has been pretty good, so I hope that bodes well for being able to observe when I actually am able to get away.
The major project is get the Farm ready for the auction, as well as continue to clean up the surrounding land of junk and tires. In addition, there are various other things, like mother's day, my birthday, Memorial Day, both kids playing ball, various parties and recitals, and the list goes on. I'm hoping that June proves to be a more relaxed month. I think it'll be hard pressed not to be.
I tried to spot NEAT through a tiny patch of open sky that I have in the SW, but it's not in the right spot. The west is the worst view I have from the house, with about a full 20 degrees blocked. I'm going to load the telescopes and take them to the farm this weekend, and I'm hoping that I get one good night to make an attempt.
I've finished the Kriege book on building a dob, and I think I'll get started on that sometime this summer. It would be nice to have it finished by fall, but I'm not sure that will happen. It might, though, if I work diligently on it. Still waiting to get final ok on the freelance project, though. Can't start without that.
A good article on Bradfield appeared in on the BBC's website the other day. An Eye on the Southern Sky gives a bit of background on the legendary comet hunter as well as talks about this most recent discovery. I've not been able to look for it since the last time I was out, but I did help determine that both Bradfield and Tabur are in the image above. The photo was posted to a message board and was shot by Steve Smith in El Paso, Texas. I did a little tweaking and fiddling with SkyChart and figured out where Tabur was supposed to be and sure enough, there was a tiny fuzzball there.
I myself am still trying to keep things in perspective, keep my modest goals in mind and not get too carried away about missing a clear night or not otherwise getting "sky time" in. I don't want to get burned out again. However, I am hoping for some additions to my kit for my birthday. Top on the list is a nice cart for hauling my stuff out the observing site at the farm (I don't want to be dependent on driving out there), a portable power supply for the same reason, and a shield for the yard light. Those will go a long way to perfecting the farm site.
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I have been devouring this book on building a large dob, and while it certainly seems within my ability to accomplish, I worry about some steps and the amount of time it will take. For example, welding the ladder frame for the mirror cell. I've never welded. Sure I could pay someone to do it, but the point of this is to keep costs down to a minimum. I could also buy a ladder & cell for $225, but that's probably 10 times the cost of the raw steel. There is an arc welder at the Farm, but it's going to be sold in the auction. I may bid on it up to what the cost of paying someone to do the welding would be, so maybe $40. But even having the welder doesn't mean I could actually do it, though I do think that welding is one of those "basic skills" that would be very handy to have.
But I'm waiting on hearing if I get a freelance job before I spend any money. Getting that will be the only way I'd be able to pay for the hardware and optics that I can't build - like the spider and focuser.
I did borrow a router, and I may be able to work a deal with my neighbor to use his shop full of really nice tools in exchange for building his web site, so there are some real possibilities to build something very nice. He had a sample of ApplePly that he'd used on some other job, and boy is that stuff nice. That would certainly be the wood to use for this project. Yes, I'm trying to keep costs down, certainly, but I also want to build something that is high quality worthy of the time I'll be putting into it. Seems like skimping on the wood is a poor choice for saving money.
So the next step is to use the KB book and work out some measurements of the various pieces for this project. The problem I have with this book is that some of the sections include tables of "standard" measurements based on mirror size that goes down to 12.5", while most of the tables only have measurements for 15" or bigger. If you're building a 20" scope you're in like Flynn because many of the examples use this baseline. However, I wish the tables were consistent with their starting measurements.
Is seems to be that for many of these sizes that you can save about 25% off the cost of the scope by building it vs. buying it complete, more if you factor in shipping costs. While not spectacular savings, at scopes of the size and style in this book it becomes real money pretty fast. Plus I want the satisfaction of building it myself. I'm not afraid of the process, but I am concerned about the time commitment. Using nice tools will be better, too, so I hope I can work that deal.
Not much observing lately, though a couple of nights have been nice. I just can't do morning observations on weekdays right now. Plus I have a cold, and that's no fun. Lots of snot. Bet you wanted to know that.
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There are two things about pre-dawn observing that I'd, well not forgotten, but hadn't really thought about in a long time: the skies are very nice and it's very hard on the body :-) A five and a half hour commitment for two hours of observing kind of sucks. Especially when it's all sleep time.
In any case, I wanted to make an attempt at 4 comets. There are two LINEAR comets in the morning sky, plus Tabur and Bradfield. I also thought it would be cool to get some sweeping in under fresh sky. So I packed up the stuff, grabbed 4 hours of sleep and then headed out to Cherry Grove.
Most of the club was at the astronomy day star party at the big observatory, and as I'd hoped I had the place to myself. I arrived at just after 2 am, got set up. It was cold, about 30F, and there was a slight breeze from the east. I was glad to have brought my heavy coat. No problems with the DSC this time. After aligning the DSC and connecting the laptop, I noticed that the scope was pointing right near reflection nebula 7023. So I nudged the scope over for a look. This was very easy at 40x, in a relatively empty field.
It was going to be a couple hours before I'd have any chance at the comets, so I just started in with the hunt, working the NE in a zone that the surveys have not covered in a while. It was exactly 3 am when I started.
I opted to skip looking for LINEAR 03K4, latest reports show it on the borderline of the ability of my scope, and just decided not to waste the time looking for it.
The dogs. There were some dogs about a half mile away at a farm house, and they just would not shut up. They were barking and barking and barking almost the whole time. They were pretty annoying.
Since I was sweeping again mostly in the NE, I was spending a lot of time in the Milky Way, so most of the objects tonight were open clusters. First was 6819, somewhat mottled. Then I found 6910 with a Y-shaped figure of bright stars. From there it was M39 which s kind of loose, and 7209 and 7086. Next up was IC1434 which is a rather rich OC with a lot of fainter stars.
After all the open clusters, M31, M32 and M110 were a nice departure, but they were to be the only galaxies this session.
Back to the open clusters: 7380 with no nebula visible, 7789, and 7510, a pretty small and tightly packs OC. There were probably others in these sweeps that I didn't note for one reason or another, these were obvious ones that I used to verify the DSC or because they were cool.
I noticed an asterism that I dubbed the "witch's hat" at 23 18 39/+63 16 5. Right after it was M52. I stopped just short of reflection nebula 7635. With the exception of M52 and the Great Nebula, all were new objects for me, and M39 is the first new M-object of the year.
It was 5 am at this point, and the sky was getting pretty light so I went looking for the comets. I knew right away that Tabur was not going to happen - latest reports put it at mag 9.5, and the sky was getting too bright. So I went for Bradfield, using the laptop to guide me over there - I couldn't see any stars that low on the horizon. I found it, very small and looking something like an unfocused star. It had a greenish look, but that might be because of it's altitude and the lightening sky more than anything. I also looked at 80x, but I could not get any hint of tail or extension. Within 5 minutes it was lost in the glow.
I went over to where LINEAR was just coming over the trees, but a band of clouds was moving over the area and blocked my view. So that was a bust and the end of the session.
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Ok, so I think I'm going to take the plunge. Over the past few weeks I've been thinking that if I really am going to seriously continue to pursue comet hunting, I need a bigger bucket. Reading Murakami's notes on comet hunting helped solidify my decision as well.
10 years ago, 8" would have been enough. But in the age of the surveys, it simply does not go deep enough to find them before the surveys bag them. Most of the recent visual discoveries from the northern hemisphere have been found with scopes larger than 12".
The only way I can possibly get to a 12 inch or greater scope that fits my criteria is to go with a truss (a solid tube like that from Discovery I feel would simply be too heavy), and the only way I can get to a truss in my financial world is to build it myself. DSCs are a must-have, and a Discovery truss at 12.5" with DSCs, shipping, etc. would push $3K - about double what I might be able to come up with in cash.
My requirements would be as follows:
- Min 12.5" aperture
- DSCs with serial output
- Must be able to set up and tear down alone (set up time isn't as much a factor as weight)
- Minimum transport volume (or it will never get to go along to the weekend (read dark sky) place).
- Good optical quality - i.e. better than your typical mass-produced dob, say Discovery quality or better
- High mechanical quality
At this point I'm not sure if I can do it on a $1500 budget and still purchase optics. Discovery optics would take more than half of that alone. Not that I'm sold on Discovery optics, it's just that they seem like the beginning of the high-end mirror makers and have a solid reputation.
There are a couple of factors with buying optics vs. grinding my own. First is that I can count on a specific focal ratio, allowing me to build the scope accurately without the mirror in hand. If I were to grind my own mirror, it'd be a drag to get to a perfect f/5.3, for example, and have the scope designed for f/5. So if you're going to grind, you have to do that first. Another factor is risking a $400 blank and possibly screwing it up. Last is, of course, time - or lack of it.
A small part of that $1500 might come from the sale of my current 8" setup, but I plan to do that after the assembly of the scope itself is completed. I am also considering selling my Pronto to offset costs, which I know I could do rather effortlessly, but in the long run would be disappointing to part with. Another possibility is building two at the same time - selling off one of them when completed to help finance the optics in the other. I am also hoping to learn that I might be able to refit my existing Meade DSCs to the new scope. While I know that the newer units are perhaps more advanced, I own this one and am satisfied with its performance.
The major impediment to building a scope myself is more plans than skill - given good instructions I can do most mechanical things, from rebuilding an engine to cooking a tasty meal. However, I'm not such a fantastic engineer, so I'm not great at improvising solutions from bits lying about. I tend to "over build" things so while it may end up functional, it's looking like slag and weighing 3 tons. Since weight and volume is a factor, I'd rather have better plans. I don't want to invest time and money into something what will result in only a marginally improved view - I can get that buying a mass-produced 10 or 12 for half of what I'm willing to pay. There isn't much in the 12.5" category except the Discovery solid-tube for $1500, after that it's manufactured trusses and they basically start at $2K. I don't want another Meade Starfinder.
After some research on the net for truss tube scope plans, it seemed like all roads lead to Richard Berry, and I've used his plans once before from "build your own telescope". So for this project, I've made the initial $30 investment and ordered The Dobsonian Telescope by David Kriege and Richard Berry. It seemed like the place to find the most complete and detailed plans. I'll have this in a couple days and I'll decide if I'm actually going to take on this after reviewing the plans.
With it being summer, I don't know how fast it'll progress, but I'll post updates.
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Windy and cool at the farm this weekend, storms on the way but they held off though the evening. After putting Annie to bed, I grabbed a pair of 7x50 binoculars and headed out to the field where I had hoped to do some observing with the telescope.
I've been thinking a lot about this, an observing "spot" - someplace that is somewhat permanent. My thoughts followed this path: once I pick a nice location, I could create a level spot for the scope. Then I'd cut a path, and perhaps smooth it out and put down some gravel or paving stones. Someday I'd like to add a shed for storing the stuff, too, so maybe a little 8x8 garden shed. From there, the whole plan just sort of snowballed into an imaginary garden centered on the telescope viewing spot.
An obvious major component to all of this would be field stones. I had my mind some low walls and things, perhaps even the foundation (or the façade of the foundation) with small field stones, a garden pond and a sundial.
Anyhow, these were the thoughts in my head as I headed out to the field and tried to find my PTO wheel in the dark.
I wandered the field a bit, and I finally kicked the wheel. The wind was fierce, but I had a hat and coat on and wasn't planning on staying out all that long.
The first thing I noticed was that the road traffic, as I'd feared, was an issue. It will be a lot better after the trees fill in, but for half the year it's going to be annoying in the evenings if I observe close to the house.
From there I took a long, sad look at the light pollution dome from Alexandria to the south. It extends up to about 20 degrees almost due south, and is about 20 degrees in diameter. After that, it seems to fade away pretty rapidly. However, I suspect that over the next 20 years, it's probably not going to get any better, in fact it's likely to get worse. That is a strike against the possibility of a permanent observatory. On the other hand, I think with the exception of that southern area, the site is as good as Cherry Grove, and the view is great to all the other directions, especially east. So, I think for morning observing it will be great, scanning NW in the summer will also be great. Winters in the evening will be poor.
Here is I think the story for light pollution and it's seasonal effect. The winter is the worst, because of the lack of foliage and lots of snow around to reflect the light. Spring and fall are medium, because there is no snow but no leaves, either. Summer is the least obtrusive because the leaves will block a lot of stray light, and this will be most noticeable on the roadway lights.
Of course, the atmosphere also plays a big part, so on a day-to-day basis the amount of sky effected will change. And it might be balanced with the increase in humidity in the summer. I don't know. But it's nice to believe that perhaps the sky will improve when the leaves fill in.
The horizons are also somewhat compromised to the west and SW from the "close" site. The main tree line to the SW, plus the buildings to the west, block the horizon to about 10-15 degrees. In the other directions I have a view nearly to the horizon.
But other than just surveying the area, I did some binocular looking. Nothing in particular to note, just some touring of open clusters and colored stars and things. It was fun.
With the wind beginning to annoy me after about a half hour, I headed back in. I guess this sounds kind of pessimistic in terms of what the farm holds in store, but it is far better than here, and it's quiet and private and has a lot of other benefits as well. So even though it isn't perfect, I'm excited...
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