Astronomy Resolutions for 2010

Here are my personal astronomy goals for the coming year:

- Complete the Herschel 400 list (I have about 300 objects to go)

- Complete the Master level of the Outreach club of the Astronomical League (about 70 more hours of star party fun)

- Learn how to do more sketching at the eyepiece (Maybe this means the open cluster club, Asteroid club, or the Lunar II club?)

- Attend the Texas Star Party for the second time.

- Find at least 3 more dark sky sites I can easily access within 2 hours of San Antonio including one with low horizons.

Dark Skies to all

Risk

Sunspots are back

Several times this December, I have taken a look at the sun with my 10 inch scope and a Baader filter. The filter works fairly well in seeing sunspots and other white light features of the sun.

Yesterday, I tried taking a few photos with my phone camera through the eyepiece. Most of the images were not very good. A few were worth looking at. The image attached to this post was taken through a 10mm Radian eyepiece at a magnification of about 120X. The cropped area is about 1/20 of the original photo. It clearly shows the two pairs of spots which I saw visually.

I have read that sunspots always appear in pairs, that the spots are the two points where a local magnetic field line crosses the visible surface of the sun. In this photo, there are two nearly equal pairs. There is an inner pair of small spots and an outer pair of larger spots. Also, spots appear in pairs that are parallel to the sun's rotation, which is approximately parallel with our rotation around the sun. These pairs did move leftward in my reflector, so the west is to the left and the east is to the right. South is up and north is down in these views.

Dark Skies, Good People

We had nice weather in San Antonio over the weekend too. Saturday evening was a club outing to a dark sky site. The weather and the company were great. I was able to finish off the December portion of the Herschel list, as O'Meara has it programmed. I am now up to date, having finished up September to December. There were some long star hops in the December list.

I spent the rest of the time in my binocular chair, doing a mini Messier Marathon of the available objects.

By morning, what had been a moderate dew, had frozen solid on my dew covers.

All in all, a nice observing night.

Cleaning a Primary Mirror

After a summer/fall of frequent observation and two major rebuilds of the furniture for my 16 inch Lightbridge optics, there was a fair amount of earthy dust and even more saw dust coating my primary mirror.

I had a good long conversation with the owner of a 24 inch StarMaster scope at the Texas Star Party about cleaning mirrors. Before forgetting all his advice, I decided to do a full baptism of my mirror last weekend.

I removed the mirror cell from the base box like I have a number of times in my building project. Taking it out is never a problem. (Putting it back in is not quite so simple. It takes a steady hand, carefully placing the mirror cell on three springs without knocking the springs over. )

Next, I removed the three mirror clamps from the periphery of the cell. That does not release the mirror, because there are four places on the periphery where black RTV calk was used to further hold the mirror in the cell. I took a sharp knife and cut through each bead of calk next to the mirror. (Marking the mirror to know what rotation angle it was in the cell is a really good idea.)

I then was able to slide the mirror out of the main cell casting. It came out with the rear-of-the-cell spider pieces attached. There are three independent supports that make up this “spider”. Each support consists of two three cornered plates on a balance beam. Each three corner plate had one sticky pad attached to the mirror with double sided paper tape. After fiddling with these tape pieces unsuccessfully for a few minutes, I just pulled the triangles off the mirror, leaving a paper spot on the mirror in 6 places.

I then took the mirror to the back porch, placed it mostly vertical against the house, and hosed the mirror off. That took most of the contamination off the mirror, I am quite sure. But I wanted to go a little further.

I filled up a roll under the bed Tupperware container about half way. This was a new container I bought for this purpose and hosed out. These containers have a bottom which is just a little more than 16 inches by about 27 inches. I put a couple drops of dish washing detergent in the water and used the hose to spread that out.

I put the mirror in the water bath with about an inch of water over the top of the mirror.

I had previously obtained some cotton balls that were 100 percent cotton. There was no way to verify that they did not have any softener in them, like surgical cotton. But they were called 100 percent cotton and did not list any other ingredients.

I used a cotton ball and gently ran it from the center of the mirror to the edge. I threw that cotton ball away and did the same with another ball just a half inch or so from the first one. I continued in this manner around the mirror – one pass of each new cotton ball from the center to the edge. My intent was to have the smallest risk of collecting a scratching grain and scratching the mirror over and over with it.

After this cleansing, I took the mirror out of the bath. I put it vertically next to the house again, and rinsed it with a quart or so of distilled water.

Almost all the water drained off the mirror leaving it without drops. There were a few drops and I collected them with the corner of a piece of toilet paper.

After the mirror had finished drying, I saw that I had missed a few places on the mirror where I had evidently not used a cotton ball. There were some small streaks of dusty appearance between my radial strokes - but there were not many. Evidently, using the cotton balls had removed a layer of dust that had remained adherent during the spray cleaning and the immersion.

After the mirror dried, I was able to put the rear support beams with triangular plates in place, and then to slide the mirror back into the cell so that the cut surfaces of the RTV calk exactly matched. I put the three mirror clamps back on. (Remember not to do this tightly.) Then The mirror cell was bolted back in the bottom box of the scope.

It was all pretty simple and the mirror was obviously much cleaner after the operation. Even just a spraying with a hose would clean the mirror a lot the next time round.

I don’t think I would do this more than every year or so, but it is nice to have a clean mirror again.

Failed Astronomy

Some nights, things just don’t work out. I had one of those nights on Sunday.

After a long week of cloudy skies, Sunday daylight broke with hints of sunshine on the top of a fog bank. As Diane and I sat in Starbucks having coffee and coffee cake, my spirits began to rise with the glucose and caffeine levels in my blood stream.

Confidently, I said that the clouds would burn off by noon and we had the potential of a clear sky for the evening. That was a nice thought because we were very close to new moon and the Geminid meteor shower was scheduled to peak before midnight.

I set about to cautiously think about an observing evening. Maybe the night would turn out well.

As I worked around the house during the afternoon, I was overjoyed to see that the sky was bright blue. The recent rain had pushed out haze and left the sky cloudless.

I looked up Hill Country State Natural Area on the internet and saw that a public hunt was scheduled to start on Monday. The park would be closed at 10 PM. That was good enough for a nice night of Herschel observing, but it was a little disappointing that the park would not be open for the peak of the meteor shower.

I called the park office, intending to let them know that I would be at our observing site that evening, and that I would be out by the 10 PM closing time. The nice ranger on the phone told me that the park would actually be closed beginning at sunset, not 10PM. Not wanting to argue, I thanked the ranger and started to think of other options.

“Oh well”, I said to myself. “I have observed from a pull off on the park road before”, and I decided that I could do it again. Yes, I knew that I could expect to have 15-20 cars with bright headlights come by, but the rest of the time I would have 5.5 magnitude stars visible. It could be a nice night of Herschel observing (maybe I could finish the December list in O’Meara’s book) and then I could settle down to watch meteors toward 10 or 11 PM. The drive home would be 10 minutes shorter as well!

I arrived at my observing spot about 6:30 PM. Diane begged out because she had some work to do as Santa’s Elf. No one else answered my email on the San Antonio Astronomy Yahoo group when I posted that I would be out near the park. I planned on being by myself. I was.

When the sky turned dark enough to see the “faint fuzzys” on the Herschel list, I pulled out the O’Meara book and reached for my trusty digital recorder. But that recorder was back in my house in Helotes, 40 minutes away. Oh Well! I looked at a couple of the objects, but lost interest fairly quickly, knowing that I was not set up to record my observations. I looked at a number of Messier objects with my 16 inch scope. But I was a bit bummed out.

About that time, I realized that the rising Orion constellation was dimming noticeably. I looked straight up. The Milky Way had disappeared too. I looked further west, and Jupiter was shining brightly and those constellations were all present.

So it was just a local cloud.

Except that about 15 minutes after the sky cleared, there was a general dimming of all the stars and then they all winked out. They stayed that way. It was 8:45 PM. I never saw another star.

On this little trip, I had experienced loss of an observing field to a “hunt” on the State Natural Area park lands. I had to set up where bright car lights spoiled my night vision every 10 minutes or so. I forgot to bring a little recorder which spoiled my ability to run the list I had intended on. And finally I was shut out by a thick bank of clouds that suddenly formed from a perfectly clear sky. The sky has stubbornly remained cloudy all week long, ever since.

I just thought I would post this, to remind me how special it is when everything works out splendidly! Surprisingly often, the weather, the moon, the place, and the gathering of friends are all perfect. As I sit here today, I am planning on that all working out for this Saturday evening.

Wishing you Dark Skies and a Merry Christmas,
Eternally the optimist,

Risk

Simple dew shields from "Fun Foam"

I went to Hobby Lobby last week to buy a few sheets of 2mm thick black foam rubber. I found them in the children's education part of the store. I bought the foam to make a backdrop for my secondary on the ring structure of my new Looking Glass.

While I was there, I bought a couple more sheets to play with. Nearly simultaneously, Matt R. was there and working with the foam. He kindly made me a pair of dew shields for the Eyes of Texas, my 80mm binocular. He also cut a sheet for my Telrad.

From my scraps of Fun Foam, I built a simple wrap-around dew shield for my 50mm finder. I built it so that I could put a hand warmer packet inside the ring if I desired.

Last night, in my observing session at Hill Country State Natural Area, the dew was pretty heavy and early. (On the way home, there were blankets of radiation fog in every valley.) I had put the finder scope dew cover on and it kept that objective clear of dew all evening. I ended up needing to wrap a hand warmer around the eyepiece of the finder with a rubber band. that worked, but I was late in choosing to do this and had to deal with occasional dew on the eyepiece.

The Telrad cover was attached by wrapping rubber band around the long axis of the Telrad base. The cover was held nicely in place by the rubber band. This kept the Telrad remarkably free of dew without sacrificing the utility of the finder.

I was finally done in for the night at about 830 PM, two hours after I began to observe, by dew forming on my secondary. I forgot to bring my hair dryer for that. With a hair dryer, I would have been able to continue for a while longer, until fog formed in the observing area.

For just a couple bucks, these "throw-away" dew covers are extremely easy to make and work very well. Their outer surfaces were *covered* with dew by the time I packed up, but the optics were nice and clear.

Best telescope for Christmas

It seems to be the time of year to help out folks that are thinking about a Christmas telescope. Let me help out some more. This is going to be simple.

If you are part of a family or a single person who thinks that looking at stars would be fun and that you want a telescope to do so, then read this blog post.

If you have read other folks say that it really would be wise to get a planisphere and you *have* to have a scope for Christmas, then read this blog post.

If you have considered a pair of 10x50 binoculars and still *must* get a scope for Christmas, then read on.

Don't go to a department store to get your scope. You still have time to get one in the mail from an internet sales place. Unless you really know what you are doing, don't go to Craig's list - and if you really knew what you are doing, why would you be reading this blog post??

What you want is the Orion XT6. It is a six inch dobsonian scope with no bells and no whistles. It comes with one eyepiece and a red dot finder. That should be all you need to find hundreds of objects in the Texas sky. It will fit in the back seat of almost any car.

If you search well on the internet, you should be able to buy it for less than $300 and get most of the shipping for under that number too.

After placing your order, the most important thing you should do is to find an astronomy club to help you find out how to use the scope. In San Antonio, do a search for the San Antonio Astronomical Association. We will help you. You will have fun.

Next most important: buy a copy of the Sky and Telescope Pocket Sky Atlas. It will be your map to the sky. A planisphere will also help. So will a pair of binoculars.

Dark skies to all, and to all a good night!

Risk

Comet Sweeper

I just finished a very nice book about Caroline Herschel by Claire Brock. The Comet Sweeper follows Caroline's rise to fame in the late 18th century. First as an assistant to Wm Herschel and later to her nephew John, Caroline had a large number of her own accomplishments of her own. The NGC catalog was mostly her organization of the o servations that the siblings made.

As a finder of comets, Caroline ranked in the upper tier of discoverers of her time. Entirely self taught, Caroline taught herself math, singing, and astronomy. When she was provided a yearly stipend by king George III she may have been the first professional female scientist and was certainly the first female professional astronomer.

For readers in the San Antonio Astronomy club, I will be making the book available at a meeting soon.

Best of the Best

As I was sitting in the back yard the other night hoping for clear
skies, I started to think about what would be on my list of the best of
the best objects in the night sky. I thought that a list of 5 might be
harder to come up with than a list of 10.

The list I came up with was:

Moon
Milky Way
Saturn
Jupiter
M42 - Orion Nebula

Next on my list might be:

M45 - Pleiades
M31 - Andromeda Galaxy
M13 - Hercules Globular Cluster
M9 - Lagoon Nebula
M57 - Ring Nebula

My 11th would be the Crab Nebula, M1.

What would be on *your* list of the 5 and 10 top night-time sky objects?

Next question I have for myself is how much do I know about these
objects? What class of object are they? What has been their history?
How far away are they? What was going on in history when the light from
them started this way? For the deep space objects, who discovered them,
and when?

Looking Glass Accessories

This wood telescope is coming along very well. Here is a photo of the scope before paint and varnish to show how much of the scope is new woodwork.

Since that photo, I have done a few modifications:

I rebuilt the focuser holder out of a piece of 1/2 inch ply wood.

I painted and varnished all the pieces of the scope.

I cut an inch and a half from the height of the scope.

I built a primary mirror cover for the lower box.

I built a new brace system for the top of the primary mirror box.

I sewed a secondary mirror cover

I sewed a container for the trusses for transport.

I modified the white nylon cover I had built for the HyperLightbridge and it now fits Looking Glass very well.

OK. Now I need some clear, dark skies after full moon. Lets put the request in.

Introducing Looking Glass II

A couple nights of work in the garage was transformed into a new telescope housing for my 16 inch Lightbridge. When I bought the scope last summer, I originally knew that I wanted to use the optics to build a new scope.

But wanting to get the scope in the field led me to a project to do a partial rebuild to correct the two main problems that I knew about with the Lightbridge. I was able to move the center of the altitude bearing up a couple inches and was able to reduce the weight of the base.

But this never really left me satisfied. I knew that I wanted to build a StarMaster type housing for the optics. I wanted to build in wood. I wanted to put something of myself in the design.

So this last weekend, I began the process. I stole some of the woodwork that I had done for the Looking Glass project - one that I called the Hyperlightbridge base.

I finished the woodwork on Tuesday evening and had a first light celebration. Last night I finished the wood with a combination of varnish and black paint.

There will still be a couple improvements. I need to build a mirror cover. I need to find a good way to transport the scope. I need to make a new cloth cover for dew.

The nice thing about building something myself is fearlessness in modifying it!

Long nights

I was able to finish up the mechanical part of the scope rebuild last night. It is about 2 inches taller than the previous version. Maybe I can adjust that. First view was the Orion nebula at 11 PM. It works!

It was harder to put the mirror cell back on the cast iron base plate than I had imagined it would be. I put the mirror cell box on my saw horse and laid down under it like a car mechanic. That allowed me to see where the springs were to finally get the first screw in.

After mounting the mirror in the base, I was pleased that the balance point was right at the top of the box, and that is with Telrad, finder scope, and eyepiece attached.

I'm thinking through paint schemes. I am thinking about black braces on the secondary housing, black trusses, a black interior to the mirror cell, black altitude bearings (half moons) and blonde varnish on most other pieces.

Anyone know a good way to paint a half moon on the half moons? Tole paining techniques might work, if I can find a good pattern to copy.

Rebuilding Looking Glass

This last weekend, I have begun to design and build a total make-over for my 16 inch Lightbridge. In this design, all the hardware outside of the spider, focuser, and optics are replaced.

The mirror cell is mounted in a square box. Crutch-like trusses will be attached to the four sides of the box. And a new and lighter secondary housing replaces the original metal design.

This is an almost all wood design, with even the truss pieces made from wood dowels.

Attached to this post, are construction photographs of the overall design at the stage I was figuring out how long to make the trusses and a photo of the secondary rings.

Gear Case with Foam Insert

Over the last couple weekends, I decided that I needed to come up with a better way to carry my Telrads, eyepieces, and other "stuff" that I use for every star party and every astronomy event.

I had been using a brown cloth bag, designed as a tool bag, and all those things were rattling around in the bottom of the bag. (The eyepieces were in their own pocket.) But I almost always found that the Telrads had been knocked around enough so that their on/off switch had rotated to on. Fortunately, a Telrad runs for a long time with its switch in the On position.

I built a wood case and bought some camera case foam. I built the foam "jig saw" shown in the photo from a 3 amp 12 volt transformer and a piece of nichrome wire.

Here you see the result of my project. If anyone in the San Antonio Astronomical Association needs some foam cut for a box, I now have the right tool for the job. Just let me know.

Dark Skies,

Risk

November Night in the Hills

Last night, after an early supper, my sweetie and I headed for the Hill Country State Natural Area. A cold front had swept through the area the night before and the sky was as dark a blue all day as I have seen for a long time. We got to the observing area a half hour after sunset and I had plenty of light to put the scope together and collimate it.

After taking a peak at Jupiter and watching a few satellites go by, I set about my Herschel List. I opened the O’Meara book to November and started running the objects. The first three nights were all in Cassiopeia. Each object was a small open cluster. The only one I recognized was the ET cluster, NGC 457. Wow! There are a lot of clusters in that small constellation.

Most of these Herschel objects were recorded by Caroline Herschel on November nights about the time of the US Revolutionary War. King George the 3rd, our war adversary, was sponsor to her brother and herself. Maybe the old codger was not so bad after all. He may have had the tea tax all wrong, but at least he supported astronomy.

After recording my Herschel observations on my recorder and enjoying the Milky Way galaxy for a bit, Diane and I headed home and were sitting in our living room by 9:15. During the summer, at 9:15 we were still waiting for the sky to get dark in a field somewhere!

It was so pretty on this moonless night, that I think I will have to go do it all over again tonight. I have four more “nights” of November to run through in O’Meara’s book.

**************

I did go back on the 17th. Beautiful night again, though it got cold. John E and I were there just after sunset and I stayed until a little after 9 PM. John still had an object he wanted to sketch before leaving.

I was able to finish up the remaining 16 Herschel objects for November. There were some nice open clusters, but it was mainly a night of searching for dim galaxies.

On the way home, a deer ran part of the way across the Texas 16 and I reacted with a hard pull on the steering wheel. My right two tires left the pavement at 60 mph. I got back on the highway without rolling the truck. Uhhh.... That was not the way I had planned on reacting to a deer.

But I got home without a scratch on the truck or the scope. Needless to say, it was not hard to stay awake after that!

Dark Skies,

Rick

Binocular Box For The Eyes of Texas

Ever since I built the Couch Potato Telescope chair, I have wanted to get a larger binocular. For a discussion on why, the patient reader may want to go back and read my blog titled “Binoculars” in June of 2009. I have looked at several different binoculars since that time and finally decided to get a medium priced 80mm binocular. Two weeks ago, I was quite pleased to see that the price of the Celestron 20x80 binoculars with braced mounting had gone from the mid $200 range to $130. At that price, the binocular was a steal!

The binocular arrived this week and a quick back-yard check of its optics was impressive. So I decided to give it a welcome home present. I should give it a name too – and what would be better than “The Eyes of Texas.”

The Eyes of Texas are upon you,
All the live long day.
The Eyes of Texas are upon you,
You cannot get away.
Do not think you can escape them,
At night, or early in the morn'.
The Eyes of Texas are upon you,
Till Gabriel blows his horn!

The binocular came in a cardboard box, with foam padding, not Styrofoam. That offered the possibility of building a good looking and practical wood instrument case for the binocular. The foam padding could be recycled as the instrument case padding.

In my building the eyepiece warming box the previous week, I had learned a couple lessons about plywood. The main learning point was that I needed a hollow ground blade for my circular saw instead of the all-purpose blade I had made the previous box with. I was tired of the badly frayed edges on some of the plywood cuts.


I wanted to dress the box up a little, so I went to the local hardware store (Home Depot) and picked up some brass colored hardware. I chose a pair of hinges of reasonable size, two bail latches, a handle, and a set of eight brass corners.

After measuring the foam block, I set about designing the box sides from ½ inch hardwood ply. I joined the sides with countersunk brass screws. Because I wanted the lid to be a little like a briefcase lid, I put a lip on the top 1-1/2 inches deep.

To the two rectangular box pieces, I screwed a top of ¼ inch Luan plywood. I varnished the wood components inside and out and set it out to dry for a couple hours. Unfortunately, there was a thunder storm at lunch time on Sunday and it took a little longer for the pieces to dry than I wanted. I was impatient to get the hardware on the box.


I put the hinges, latches, and handle on. Lastly, I screwed on the corners. This ended up being a very handsome box for The Eyes of Texas and she seemed to enjoy it.

Last night, Matt R and I went out to Hill Country State Natural Area and did some star gazing in a dark sky. Conditions were not perfect – there was a lot of moisture in the air – but I had a couple involuntary “Wow”s after I attached the binocular to the rotating binocular chair. I don’t believe I have ever seen M31 to the extent that I saw it through that binocular last night. M110 was easily visible in the same field along with M32. I scanned through the Messier objects in Sagittarius and the Milky Way above it and was quite pleased with my purchase and with first dark sky light on those Big Eyes.

Warm Eyepiece Box

When I was at the Eldorado star party last month, I listened to a talk on dew heaters. It was appropriate because the dew at this party was hard to deal with. This was the first time that I needed to break out my hair dryer for optics.

One of the problems I had was the new mount for my eyepieces on the side of the Looking Glass scope. The eyepieces, sitting there radiating all their heat into a clear sky cooled very quickly and began to collect dew.

I was able to cope with that a little by laying a clean sock over the top of eyepieces with a hand warmer in the sock. However I knew there must be a better way. So I began to think of options.

Two weeks ago, I finally sat down to build a small box that can hang on the side of my scope. It has room for my three most often used eyepieces and the three-hole receiver can be removed so that a hand warmer can be dropped into the bottom of the box.

I have used the box several times now. I have not had to use a hand warmer, as the dew has not been so bad again, but I have discovered that I spend less time watching folks at public star parties. Having those eyepieces in a container makes me worry less about them.

It’s a Big Galaxy Out There

Last month, I was trying to remember how far away an open star cluster was. I was showcasing NGC 457 at a state park star party. This cluster is a cute appearing cluster in Cassiopeia. It is called the ET cluster or the Owl cluster. For kids these days, I call it the WALL-E cluster.

Since I could not remember its distance, I came up with something that seemed like it might make sense. I said that it was probably a couple hundred light years away. Boy was I wrong. I should have just said that I could not remember. Now there are maybe a dozen kids and parents roaming the world thinking that ET is a lot closer to home than he really is…

Of course, hundreds of light years away is still a long, long way.

Here is one way of thinking of these distances. It is about 3000 miles from the east coast of the US to the west coast. The circumference of the earth is about 24000 miles. Light travels at about 186000 miles in one second.

That means it would take about 1/7 of a second for light to circle the earth. 1/50th of a second is all it would take for light to make it from the left coast to the right coast of the US.

The moon is about 240,000 miles from the earth on average. So it takes about 1-1/3 seconds for light to travel from the moon to the earth. The sun is about 93,000,000 miles from earth. So it takes about 500 seconds or 8-1/3 minutes for the light from the sun to reach the earth.

Jupiter is hanging high in the evening sky right now. It is about 484 million miles from the sun. That is five times as far as the earth is from the sun. One way to talk about distances in the solar system is to measure in Astronomical Units (AU). One AU is the average distance of the earth from the sun. Jupiter’s distance from earth ranges from 4 AU to 6AU. In light minutes, Jupiter’s distance from the sun is about 41 minutes. But when I look at Jupiter right now, the time it takes for light to leave the sun, travel to Jupiter, reflect off the clouds and come back to my eye is closer to 80 minutes – almost an hour and a half.

I was pointing out Neptune to one of our club members from the light polluted city streets of San Antonio last week. Neptune is 4.5 billion miles from the sun. That is about 6.7 light hours from the sun. When I was pointing out Neptune, its light had been traveling for more than 13 hours since it left the surface of the sun. Another way to think of Neptune’s distance is that it is about a million times as far away as the distance across our country.

But that’s just peanuts.

The second nearest star is about 3 light years away. That’s 2000 times as far away as Neptune. Sirius, the brightest star in our sky is about 8-1/2 light years away. Star clusters are much further away. The Pleiades are a close cluster and are about 440 light years away. Maybe that is what I was thinking when I told my listeners that the ET cluster was several hundred light years away. As it is, the light from the Pleiades left those young suns about the time that Galileo was born.

But the ET cluster is a lot further away. When I finally looked it up while hiking yesterday, I was taken back when I read that this cute little open cluster is about 9000 light years away. The light I looked at the other night started heading this way about the time that people first began writing in Mesopotamia and the Chinese began making wine.

That’s a long time ago, and the galaxy we live in is a big place.

Astronomers look out for themselves

I've been at the Eldorado Star Party for the last couple days. The weather has been nice, with clear skies and pleasant temperatures. There was some rain in the last week and that has made dew a bit of a problem, and hair driers are frequently heard on the starfield at night.



Last night, Matt R. And I began the Texas Hash list. It is a lot harder than most of the TSP lists I ran last spring. We got through 15 objects we attempted last night, with only one object we could not find. We have another 10 to go tonight if we decide to proceed with the list.

It was sometime yesterday, while cleaning up camp to leave for lunch, that the title of this post occurred to me. We were talking about the fact that astronomers were a pretty honest crew. Nevertheless, it is never a good idea to leave expensive items lying around. We were cleaning up, "Because astronomers look out for themselves."

I laughed at the appropriateness of the words, because that is exactly what we do. Instead of looking at pictures of stars in books or the Internet, we stay up late at night to find and admire those objects ourselves. That is why it is about.

National Night Out

Last evening, I remembered that it was our Texas version of National Night Out (NNO) when I saw the 6PM news coverage of some events near San Antonio. Some months ago I had decided that the NNO might make a great time to have a neighborhood star party.

I walked to the front of the house and saw that the sky was relatively clear. We have recently had a lot of clouds, and I was a little surprised that there were few clouds in the sky.

It took almost 5 minutes to set up my Orion XT10 in the driveway and focus it on Jupiter. With a 10 mm eyepiece, the magnification was 120 times and the brightness was such that the bands of Jupiter were clearly visible.

Three star-like moons were arrayed to the right of Jupiter, toward the East it turns out. Jupiter would slip off the left side of the field of view every couple minutes. The fourth major moon of Jupiter was not visible behind its disc.

The top equitorial band (the southern one) had a great lump in its top edge. There was a small dark spot just to the right side of the lump within the band. In moments of clarity and improved seeing, I could make out the internal border of the Great Red Spot. Over the course of the evening, that Red Spot moved leftward (westward) until it seemed to be falling off the left side of the Jupiter "marble".

During the two hours I had my scope up, different groups of my neighbors that had been at the formal celebration of NNO at our pool walked past the house. I genially called them over to take a look at Jupiter. One group of kids, with their mom, spent quite a bit of time learning how to readjust the scope to put Jupiter back in the center of the field of view.

They had lots of good questions. How big is Jupiter compared with Mars and with Earth? How far away is it? Why are the moons in a line? What causes the bands on Jupiter and the Great Red Spot?

I had done some thinking since a couple recent star parties, and decided to try to answer the questions with the purpose of helping them to think about the process of science instead of a science text book. The same way that I had helped them learn to find Jupiter when it slid out of the field of view, instead of doing that myself, I wanted them to think about the answers to their questions.

So I helped them think through their questions instead of giving them textbook answers. How could one find out how big Jupiter is? How would it be possible to find out how far away Jupiter is? How long does it take for light from Jupiter to get to the earth? Why would you believe my answers when there are good ways of finding out answers?

It was interesting to see their reaction. They clearly expected to be told the answers to their questions - just like I was some kind of encyclopedia or Google search engine. But when I started asking questions in return, they either took it well or did not. Some were interested in the guy with the telescope that asked questions and some were bored.

I hope the effort will encourage some kid to get a little more interested in science questions. Maybe they will become interested enough to take a little more science than they were expecting to take in school. Maybe they will make a little better citizen or jurror in a case that involves scientific testimony. Maybe one of them will invent the cure for whatever disease or injury is going to try to do me in 20 years from now - or one of my children or grandchildren.

It felt good to challenge my charges a little.

Dark Skies!
Risk

Astronomy and Fitness

Over the last eight or nine months, as I have become more and more interested in astronomy, I have taken less time to hike and walk and ride my mountain bike. Unfortunately, I found that this had an effect on my weight and my waistline. My weight rose from about 185 to 215 pounds. At first, my 36 inch waist pants got tight and then intolerable. I moved to 38 inch waist pants and then they got tight too!

It is time for me to become a shadow of my present self. I need to weigh less. I need to be in better shape.

This week, my wife persuaded me to start joining her in regularly attending a health club. She has been very good at getting exercise for most of a year now, and finally I am on the way back to health too. I thank her for the encouragement and inspiration.

We decided to plunk down the money to join the local Spectrum health club after visiting the local clubs. Spectrum was lighter, a little less crowded, and smelled better than the other club we visited. It is close enough that I can get there after working my day job, instead of just wishing that I could drive to Lackland AFB to use their gym for free. Yeah, it was also a little more expensive.

So, here I am a few days later with some soreness of my muscles and I’m slowly starting my way down the weight loss path again. (I am reducing portion sizes and abandoning all snacks too.) I know it will take a number of months to get back down to fighting weight, but the journey has started.

Astronomy is a great activity, but the problem with it is that there is not much activity to it. If you are having as much fun under the dark sky as I am, maybe a review of your other activities is in order – like it was for me. We want to enjoy the sky for as many years as possible. Staying in shape and staying healthy is part of that equation.

Huff and puff,
Dark skies too,

Rick

Free Tools – Cartes Du Ciel and Virtual Moon Atlas

One of the premier tools available free to the amateur observer is the planetarium program that goes by the French name “Cartes Du Ciel.” True to its name, this program is a Sky Chart system that incorporates many of the features of full feature programs costing hundreds of dollars.

I have a number of sky charts that I find to be very useful in book form. When I am searching for a double star or a Messier Object, I really like these bound versions of sky charts. However, for some purposes, a software program is very handy. That is especially true when trying to track down comets, planets, and asteroids. The planetarium program can be set for today, or for next week when I will be out at a dark sky site. It can give different magnification levels, and I can create both right side up views for my finder scope as well as upside down and backwards views for my Dobsonian scope. Fact is, the program will also create right side up and reversed left right views for SCT scopes too!

For planning a Messier Marathon, the program is a great way to create a set of star hopping charts or to add to a published set, as I described in my Messier marathon piece last winter.

My preferred set up is to use a black on white format. It prints very well. With a red filter on a laptop computer it is also easy to read in the dark.

One of the ways I use the program is to print out a full sky chart to use instead of a planisphere for a certain time/place/and date. It is a little easier to show constellations to folks with this round version of the sky than a squished planisphere version – it also is more accurate than most planispheres for my south Texas observing location.

One of the things I like most about the Cartes du Ciel program is the ability to scale to any magnification and to add or subract star detail. This allows me to create simple charts and detailed charts on the fly. If I am interested in seeing very dim stars near where an asteroid is to be found in an eyepiece view, I can do that. If I am interested in seeing the overall picture of a full constellation, I can do that too.

Switching gears, I might as well mention the lunar equivalent of this planetarium program. The “Virtual Moon Atlas” is a great tool for locating almost all the small objects that one might be interested in on the lunar surface. It is a searchable atlas, and will identify any crater or feature that I click on the picture of the moon. There are several levels of complexity of the moon atlas. I have always used the biggest version. I really don’t know how limited the other versions might be.
Again the cool thing about this atlas is that it follows the libration of the moon, the phases of the moon, and the visible portion of the moon from any observing location. The view can also be adjusted up/down and left/right for any sort of scope.

Both programs can be downloaded from the Internet. Google search for them, download, install, and enjoy.

Astronomy Picture of the Day

While I am an incurable fan of looking at my own personal set of photons given off by deep sky objects, I can also be attracted to beautiful photographs of the same sky objects. I grew up with black and white versions of long photographic exposure time pictures that showed much more than I can see with my eye. These days, color photos and false color photos are all the rage. They are beautiful.

Sometime last fall, I decided to take an online course offered free by Robert Nemiroff (Michigan Technical University) from the upper peninsula of the state. It was an online collection of the lectures used for a college course. They were offered completely free as long as no college credit was needed. Dr Nemiroff is one of the editors of the Astronomy Picture of the Day (APOD). This is a NASA hosted site where one photograph or piece of art is featured each day. In the course, the students were responsible for knowing something about each one of the APODs for their testes.

I started taking a closer look at the descriptions under the pretty pictures. It turns out that the writing about the photographs is as well done as the photography. Here is a recent example:

“Why take a picture of just the Badlands when you can take one that also shows the spectacular sky above it? Just such a picture, actually a digital stitched panorama of four images, was taken in late June near midnight, looking southwest. In the foreground, the unusual buttes of the Badlands Wall, part of the Badlands National Park in South Dakota, USA, were momentarily illuminated by flashlight during a long duration exposure of the background night sky. The mountain-like buttes visible are composed of soft rock that show sharp erosion features from wind and water. The South Dakota Badlands also contain ancient beds rich with easy-to-find fossils. Some fossils are over 25 million years old and hold clues to the evolutionary origins of the horse and the saber-toothed tiger. Bright Jupiter dominates the sky on the left just above the buttes, while the spectacular Milky Way Galaxy runs down the image right.”

When I take a careful look at this prose, it is as illuminating as the photograph it described. Here is another recent description from the APOD site:

“Sprawling across hundreds of light-years, emission nebula IC 1396, visible on the upper right, mixes glowing cosmic gas and dark dust clouds. Stars are forming in this area, only about 3,000 light-years from Earth. This wide angle view also captures surrounding emission and absorption nebula. The red glow in IC 1396 and across the image is created by cosmic hydrogen gas recapturing electrons knocked away by energetic starlight. The dark dust clouds are dense groups of smoke-like particles common in the disks of spiral galaxies. Among the intriguing dark shapes within IC 1396, the winding Elephant's Trunk nebula lies just right of the nebula's center. IC 1396 lies in the high and far off constellation of Cepheus.”

I like the idea of the nebula sprawling across the heavens instead of many more prosaic ways of saying the same thing. I might have written something like “IC1396 I several hundred light years in diameter.”

I got into the habit of looking at the APOD each day while I was taking the course last fall. I keep a link to the APOD on my blog site. It is one of the great internet archives of both beautiful photographs and instructive descriptions of deep sky objects. There is a lot of cosmology to be learned just by reading the descriptions from a month’s worth of the APOD library. Enjoy them.

The daily APOD can be found at

http://apod.nasa.gov/apod/

Risk Management in Astronomy

One of my nicknames is Risk. Hence, “Risk’s Wildly Successful” series of helpful insights. The way I came across that nickname was my function in an Air Force laboratory as the champion for Risk Management.

Life would be pretty boring if risk was always eliminated or minimized. My goal has never been to eliminate risk, but to control it – and to never let risk control me. I enjoy the heart pounding experience of pushing my limits on a mountain bike, teeth chattering as I descend a rocky trail. I enjoy the experience of standing in front of 300 people with a brand new talk, knowing that a few of those people may know more about the subject than I do. I enjoy reading people’s faces and knowing whether I am talking over their heads, or whether I am being dreadfully boring. These sorts of things are the spice of life.

Something happened this weekend which brought back to my mind the necessity of practicing Risk Management in Astronomy. We were on the way back from Hill Country State Natural Area. My son was in the pick-up with me and his fiancée was in our Corolla with Diane. It was about midnight.

Somewhere on Bandera Highway, Diane fell asleep for a moment. She was driving the car and drifted left of the yellow line. Ashley was sleepy but awake enough to know that Diane was not playing a joke on her. She quickly woke Diane and both of them drove the rest of the way home with a fresh pile of adrenaline in their veins!

Its not that our family is unaware of the dangers of driving sleepy. I personally think it is now more of a problem than “driving drunk” for our society. Driving drunk may have been more of a problem in the past, but most people now know the severe penalties for driving drunk and avoid doing so.

That brought to mind the kinds of risks that we astronomers need to control in our sport. We all know the risk of looking at the sun with a telescope. It will instantly and permanently ruin eyesight to look at the sun with aided optics. But how many of us are very careful when moving a scope around during the daytime? I remember one time this summer when I happened to glance down the tube of a reflector to see how much dust was on the mirror. The sun’s reflection hit me hard in one eye! Stupid, stupid, stupid! It took 5 minutes before I was convinced that my eye was not damaged.

Driving around at night, we not only run the risk of falling asleep, but we have to stay on the alert for large animals in the roadway. Here in Texas, that means deer and pigs. Driving back from Hill Country, Diane and I have counted up to 17 deer next to the highway.

We have to be careful about heavy scopes hurting our backs, tripping over tent stakes, and letting large scopes crush fingers and hands. These are not idle threats. As I have written, the reason I got a nice camping spot at the Texas Star Party this year was that a fellow tripped over a tent stake going to a restroom and broke his leg.

We need to be careful about being alone in lonely places. The only people who have bothered me while observing at the side of the road have been policemen. But other observers have not been quite as lucky. We need to be ready to defend ourselves while in lonely places. We also need to make sure that we have permission to be observing. One significant form of my risk management is developing friendships of folks that are willing to allow me to observe from their property instead of stopping along lonely roads like I used to do.

But learning to only drive while awake remains the most important risk management technique. There are two means of controlling this problem. The first is to learn how to stay out all night. This takes some equipment and experience. The second control mechanism is to learn to stop driving whenever I get sleepy – before getting so sleepy that I nod off. It does not matter if I am 10 miles from home or 1 mile from home. There is ALWAYS someplace where I can pull off the road and take a short nap. Even a 10 minute nap will give me many more minutes of awake time. It is always OK to stop to sleep. Dad is not at home looking at his watch. Go to sleep after the wheels stop rolling. Really. Please.

Satellite Observing

Sometimes it is a challenge to find something to do after the scope is set up at a remote location and before the sky turns inky black. One thing that an observer can do while waiting for regular observing is to look for low earth orbit satellites. The activity can be done alone or with groups. Diane and I find it especially nice to work together. We share the tasks: reading a list of times and azimuths for satellites that will come over, and recording times when the satellite passes celestial landmarks. We also compete with each other to be the first to see a satellite.

There are several tools available for finding satellites. All of the tools I use involve computers and internet resources.

One easy source for finding out what bright satellites can be seen is Heavens-Above (http://www.heavens-above.com). You tell the site where you are and it will tell you what bright satellites will be visible in the coming evening and morning. Heavens-Above lists both the satellites that are on the publicly available lists and other satellites which are not published. Most of these are the so called “spy satellites” put up by our country and others. They are often big bright satellites, the size of the Hubble Space Telescope, but aimed at earth instead of at the stars.

I have an Ipod Touch. One day I will have an Iphone if I am good and have enough patience. These devices have a couple “apps” that are handy for satellite observing. I downloaded the free ISSLite program from VosWorx. It downloads orbital information from the web and helps folks that want to watch the International Space Station and any Progress spacecraft or Space Shuttle passes. The program lists the passes that will be visible for a location for the next week and it gives two views of the orbital movement of the spacecraft. One view is the traditional view seen at Houston mission control – the sinusoidal wave of the space craft position. The other view is a 3-D rendering of the earth (and the earth can be spun around) which makes for a pretty good tool to explain the traditional view.

Having up-to-date information on satellites is important. Their orbits change over time, and sometimes the change is rapid. Orbits are defined by a series of numbers – there are several that are important to plug into equations to allow calculation of the satellite’s position in space and the viewing angle from an observer’s location. Fortunately, the computer programs that I am writing about here know how to import the numbers – officially called orbital elements or Keplarian orbital elements – and work the advanced math necessary to calculate where a satellite may be visible. As an observer, I need to tell a program where I am on the surface of the earth, and I need to download a current version of the “keps” which are also sometimes called the NORAD Database or the “els”.

There is an advanced version of the ISSLite program that will follow a much larger group of satellites – amateur radio sats, and bright visual sats among the group. That program is also distributed by VosWorx and is called ProSat. It cost about $10 to download. It is worth every penny IMHO.

There are also programs available for laptop computers. One that I have been using recently is Earth Orbiting Objects or EOO. This program, written by Steve Boucher, allows download of recent keps, allows one to store multiple observing locations and does everything that the ProSat program does. It goes one step further. It allows me to see a view of the sky with the simulated satellite going past the starry background. That is, it contains a planetarium program which shows the movement of a satellite across the sky. It can be set up so that it will show in near-real time where a satellite is. That is really good for both finding a dim satellite and for replaying a satellite passage to remember the pass with greater accuracy.

One activity involving satellites and telescope has been a real challenge for me. It is an activity for the nimble observer. On a space station passage, try following the station with a telescope at about 120-150X magnification. For me, it took using a Telrad, a finder scope, and quick reflexes. I was rewarded with a series of views of the station with enough resolution that I could see a distinct rectangular shape and a different color for the station’s wings than for its central occupied core.

A second activity can be done either at dusk/dawn or sometimes in bright sunlight. That is the observation of Iridium flares. The Iridium satellites (used by the global telephone system of the same name) have very bright mirror like sides and they can “flash” an observer with surprisingly bright flares of light. At a maximum they may reach -8 magnitude – much brighter than Venus. The best source of information about Iridium flares for me has been the Heavens-Above site mentioned at the top of this piece.

So, next time you see me with my scope all set up and the sky not yet dark, if no one has engaged me in an interesting conversation and you wonder what I might be doing with all those pieces of paper, my iPod, and a voice recorder… well now you know the rest of the story.

Observing Chair/Step Stool

When I get sawdust and plane curls going in one project, it often leads to another.

Having just finished the base for Looking Glass, I decided to solve the problem that Diane had looking at M13 the other night. Hercules is nearly at the zenith in the evening this time of year, and My first mate was not quite tall enough to see through the vertical scope and that led to contortions as she tried to keep her toes on the rungs of my observing stool, holding onto my shoulders to not fall over.

I remembered a chair that I had taken at the Texas Star Party, made by StarMaster. My neighbor at the TSP had a used one for sale and I thought the idea was clever.

I thought about that design and decided that I could make a similar device for about 5 dollars in materials. I made the two "ladders" from 2x2s. The total lumber was four of these inexpensive boards. I had a scrap of 3/4 inch plywood from the scope project, and that made a good platform.

The step can be moved to any of the "rungs" on the seat. That allows Diane to stand on a low step for a quick observation. The same usefulness will probably be enjoyed by kids at public star parties. The four foot height of the rails may give them something to hold onto instead of the scope too. But the design is also an observing stool with multiple levels.

My thanks to the folks at StarMaster who built the version that I saw. I recommend their design as a great way to show people wonders and for the observer to sit down and enjoy an object.

HyperLightbridge Base

Last week, my Meade Lightbridge (aka Looking Glass) arrived in Helotes, TX. I had ordered it with the plan to rebuild it, and this weekend I had the chance to do so. I had previously practiced building some of the design features on the Resurrection scope – large diameter altitude bearing and a small base. So, on my way home from work on Friday I picked up a 4x8 sheet of birch plywood ¾ of an inch thick with great expectations for construction.

I had drawn up a sketch of my idea and a cut plan for the sheet of plywood:

Sketch

Cut Plan

On Saturday evening, the first thing I did was to cut out the two three-foot-diameter semi-circles with a router and a circle cutting jig. This jig was a piece of Masonite cut and drilled to fit the base of my router with an arm that extended out toward the operator. (I got the idea for this by searching the Internet for “router circle cutting jig”.) I measured from the inside edge of a straight router bit to a spot 18 inches down that arm and drilled a hole that would be the center of my 3 foot half circle altitude bearing. I screwed the jig ¼ inch from the edge of the plywood and 18 inches from one end. I then cut through the plywood about a quarter inch at a time around the arc.

After cutting these two half circles, I cut a strip of bumpy fiber reinforced plastic (FRP) ¾ of an inch wide and as long as the half circumference. That was about 57 inches (pi*18). I coated the back surface of the FRP and the round surface of the altitude bearings with two coats of contact cement. After about 10 minutes of dry time, I began at one end of the strip and pressed the strip on the edge. After getting the whole strip on, I used the floor to press the strip on very securely by rolling the semi-circle against the garage floor. Then it was time for a night’s sleep.

The next morning, I used a plane to trim the width of the FRP to the width of the plywood, which is actually 1/16 of an inch under ¾ of an inch.

Then I set about cutting the box pieces to hold the sides of the light bucket. I unscrewed the mirror cell from the bucket walls and lifted the top of the bucket off the mirror cell. I put the mirror cell in the house, away from saw dust. (I also took this opportunity to adjust the mirror holding brackets so that they do not press too firmly on the edges of the mirror.) I measured the diameter of the bucket several places and decided that it was very close to 19 inches. I added the width of my plywood to that and came up just below 19-3/4 inches. I knew that I wanted four identical pieces of plywood 12x19-3/4. I also needed a base and a ground board.

I very carefully measured and drew cutting lines on the plywood. First, I cut the plywood with a circular saw so that I had a 48x48 inch piece. I then divided that into two 24x48 inch pieces and then two more cuts gave me four 24x24 inch pieces. Two of those pieces I cut to 19-3/4 inches long, and then each of them was divided to one foot widths. I put the two remaining 2x2 foot pieces to the side until I discovered exactly what size the base would need to be.

I routed the long edges of each of the box sides, top and bottom, with a round off router bit. Then I drilled and countersunk three screw holes on one end of each of the box pieces. I assembled the box, making sure to drill a pilot hole for each of the 1-1/4 inch drywall screws.
I removed the aluminum altitude bearings from the light bucket. Then I slipped the box over the bucket and secured it to the bucket with a ¾ inch wood screw through two of the holes which had held the aluminum altitude bearings.

My plan was to have the center of my 3 foot diameter altitude bearing at the center of the upper edge of the box. I knew, from the collected wisdom of many owners that the scope was bottom heavy. I confirmed this on my scope when I attached a radian eyepiece, a Telrad finder, and a finder scope to the secondary housing. When my Looking Glass approached level, it wanted to nose dive. I also knew from the collected wisdom of the group that moving the center of the altitude bearing an inch up would make a world of difference. That was where I attached the box – with its upper edge an inch and a quarter above the center of the factory bearing. I also attached a third screw to the topside (opposite the seam in the bucket) to reduce rotary movement of the scope in the box.

I attached the half-round altitude bearings to the box with home made knobs and tee-nuts. I made the knobs by threading three 1-1/4 inch diameter ¼ inch fender washers over a 2 inch long 1/4x20 hex bolt and tightening them down with a nylon insert nut. I drilled ¼ inch holes through the bearing and the box in locations which spread the load and which gave me room to work between the bucket and the box. Then I drilled the box holes to accept a 1/4x20 Tee-nut and drew that Tee into the wood with a hex bolt and a washer. This makes it easy to remove the two altitude bearings from the light bucket without tools. A minute or two is all it takes to install or remove the large bearings. Of course, the bearings were oriented so that they allow both vertical and horizontal use of the scope.

I measured the width between the outer edges of the altitude bearings to make sure that they were parallel. They were just a little under 22 inches from side to side at three locations – ends and middle. That was very good news. All my careful cutting had paid off. Now I was able to build the base.

The width of the base would be the same as the width of the altitude bearings. I cut both the remaining 2x2 foot boards to 21-7/8 inch squares. I rounded off the corners of the ground board by using a varnish can to trace ¼ circles at each corner.

Next I needed to know how high the base needed to be at the center. I measured how far the corner of the light bucket extended outside the altitude bearing. It was about 2 inches. Allowing room for the center screw on which the telescope would rotate, I decided to make the center 3 inches tall. I marked that height at the 11 inch center of a 22 inch piece I was drawing on the part of the plywood from which I had cut the two three foot circles. I used an altitude bearing to draw a curved upper edge so that the bottom center was 3 inches tall and the sides were even. It ended up being about 6-1/2 inches on each side.

At this point, a bunch of routing was done to round off edges. The bottom edge of the rotating base board was routed. The outside corners of the two supports (with the concave rounded edges) and most of their round surface was rounded. Both top and bottom of the ground board were routed. The full edges inside and out of the altitude bearings including the FRP was rounded – the FRP only slightly.

A 5/16 inch hole was cut in the center of the base and ground boards. (To do this easily, place a straight edge from corner to corner and draw an X in the center. A 5/16 Tee nut was placed in the bottom surface of the ground board after that hole was drilled one size larger.

The side supports were screwed to the base from below with countersunk drywall screws. A brace was cut for both the front and the back of the base, adding strength to the support sides. The front was cut to length from one of the 4-1/2 inch wide pieces left over from the cutting of the box sides. The rear brace needs to be a little shorter to allow the swing of the telescope. 3 or 3-1/2 inches tall works pretty well. These braces are screwed to the sides of the supports and to the base. All holes are countersunk.

Only a little bit of work remained. I used the lazy susan azimuth bearing from the stock base, except that I also placed three felt furniture pads just outside the circumference of that bearing. I cut about half the thickness of the pads off so that the azimuth bearing is smooth, but does not turn in the wind. I attached square furniture glides on the upper rails of the supports. (I left small areas which were not routed so that the full width of the rail would support the furniture glide.) I also attached pieces of 1” aluminum bar, cut 2 inches long and drilled to be attached to the outside edges of the supports.

I cut triangular braces for the box, one for each corner, 4-1/2 inches wide. This is to strengthen the box so that a handle can be attached. The handles make it much easier to carry the light bucket. They also allow two people (I’m not strong enough to do it by myself) to lift the scope from the base after it is assembled.

I put a handle on one of the braces for the base, and it can easily be carried on one hand while carrying the bearings or the secondary housing in the other hand.

I really like the feel of the scope now. It is much easier to move around. The light bucket with mirror attached is still a heavy item. My only recourse if I had to move the scope a long way by myself would be to use a hand truck or to remove the mirror cell from the light bucket. That is not too hard, but it would still be a bit of a pain.

Resurrection Scope

A month ago, there was an announcement on our local astronomy group’s web page about a telescope that had been found in the garbage. Was anyone interested in seeing if it could be rescued? I responded right away because I had in mind a project that required an optical tube.

I made a call and got directions to come pick up the relic. The scope was rescued from the trash by a friendly fellow. He got a bike that he wanted and he knew someone in the SAAA and found out how to post a notice that he had this “partial telescope”.

When I went to collect the scope, I learned from the neighbor that the scope had been in a lady's garage since 1985. She had recently died and her extended family had thrown out several things that were considered useless by them. The home was off Ingram Rd just inside 410 in San Antonio.

The scope was originally put together by her son, I learned. He was 16 years old when he went to China on a youth missionary trip in 1985. He contracted an infectious disease and died there. His family was unable to even bring his body back to the US because of fears of the infection. I was told they eventually got him buried in Hawaii. If anyone ends up knowing anything about this unfortunate telescope builder, drop me a line and I will update the entry here.

The scope was about a dirty as could be expected from sitting unprotected in a garage for 25 years. It was the optical tube from a reflector telescope. There was a 1.5 inch sighting scope screwed into the tube next to a broken down focuser. The secondary hung by a wire from the focuser and bounced back and forth like a scared kitten. The mirror was labeled on the back as American Optical and had a focal length of about 67 inches.

I disassembled the finder scope and cleaned the lenses. It was usable, though the mount was not of the modern type that fits into a base. The tube had a strange collection of nuts all strung out on an unreinforced two inch long 3/16 inch bolt at about the balance point. Maybe it had once been attached to a tripod by that bolt.

I removed the mirror cell and then the mirror. I submerged the mirror in a tub of water with a little detergent. After soaking, I gently removed the accumulated crud on the mirror with a series of surgical cotton balls. I used each one for a very short cleaning stroke. After cleaning the mirror in this way, I rinsed it with water out of my Culligan filter and then touched the corner of a paper towel to each water drop that did not run off the mirror surface when it was hung vertically. There was one small flaw in the mirror coating about an eighth of an inch in diameter and my work did not seem to have introduced any scratches in the coating.

I reassembled the mirror cell with double sided sticky tape and checked out the optics. Even though the focuser was very difficult to use, and the secondary holder bobbed around, I was able to see that it would focus and give me a decent image.

So I set about doing what I had intended from the beginning. I started building a large diameter altitude bearing dobsonian mount.

I designed the altitude bearing to be two feet in diameter and wrapped the tube in a box a foot long. I made the altitude bearing half moons to be removable with knobs made from bolts and washers. I built the base from two round circles 20 inches in diameter. All these were made from ½ inch hardwood plywood, with the altitude half circles made in double thickness, an inch thick.

I made the bearing surface of each axis from fiber reinforced plastic with sliders made from pieces I cut out from a kitchen cutting board.

I designed a saw blade spring secondary spider to replace the original bouncy secondary holder. The new one is rock solid. I also bought an inexpensive ($40) 1-1/4 inch focuser from Orion.

The project cost about $45 in wood, $45 in hardware, and $40 for the focuser. It ended up being a reasonable deal for a pretty nice 8 inch scope. It also helped me to explore several technologies I needed to understand for my project intended to replace the stock base of a Meade 16 inch Lightbridge.

The photograph shows all the pieces. I had taken them apart to varnish all the surfaces. It was a good photo opportunity. All edges were routed to make them approximate a half round. The bearing surface of the half circles was also routed but not as deeply.

First Light – Looking Glass

I enjoy the tradition of celebrating the first time that a telescope is pointed to the sky. Yesterday I had the privilege of assembling my new Meade 16 inch Lightbridge telescope and (miracle that it was) the sky was clear during the evening hours.

The scope went together easily. The directions were clear enough and no pieces were missing. It took me a few minutes to discover a way to easily mount the focuser/secondary ring. But once I learned that a case wedged between the base and the light bucket holds the bucket at a 15 degree angle, putting the top ring on was much easier. I replaced the screws in the secondary with a set of Bob’s Knobs.

I made the scope a little welcome home gift while I was waiting for the sky to turn dark. I made a shroud to cover its bare midriff from 1-1/8 yards of black bathing suit liner. The stretchy material was on sale at Hancock Fabrics, so the shroud cost less than $10 and fits better than a shroud sold by the manufacturer – for ten times the price. It took about 10 minutes at the sewing machine to complete the project and thread a couple bungee cords in the hem at each end of the shroud. (Thanks to the Starmaster folks for this idea on the construction of a shroud.)

I discovered that the oversize reflective cover that I bought for my 10” Texas scope at the Texas Star Party fits this larger scope just about perfectly.

Then, finally, it was dark enough to begin to look around the sky. The moon was near full and I was in my semi-dark Helotes (Texas) neighborhood, so it was not a night for deep sky observing. First object was Vega. I wanted to adjust the Telrad and finder scope for this scope. I did not hear any strains Contact or Jodi Foster's voice as I was collecting those 20 year old photons. Next up was Mizar, the visual/telescopic double in UMA.

As it grew a little darker (and several satellites later) I went back to Vega and took a left turn to look at epsilon Lyrae, the double-double. I ran through my eyepieces, including the supplied 2” 26 mm that came with the scope. It was easy to split each of the pairs with all my usual eyepieces except the 36mm Plossel, as expected. I pushed right and found the Lyrae pair at the end of the constellation. I set the cross hairs of the finder scope to the position of the Ring Nebula. Despite the washed out sky, the Ring was quite pretty. With my 10mm Radian eyepiece, it appeared to have some color. In a dark sky this may be a very pretty sight.

Luna finally rose above my neighbor’s roof top and I experimented with a moon filter. At 180X, my view of a number of mountain peaks along the terminator was pretty good. Not great, as the San Antonio heat was still warming the air near the roofs and the view was not steady. After looking around at high power, I put the 2 inch lens in and looked at the whole moon. It looked so pretty that I decided to get my simple digital camera and take some pictures with it, up next to the eyepiece. The photo at the top of this column is one of those pictures.

At 11 PM, Jupiter was above the housetops and the Great Red Spot was turning the bend toward the west. I looked in vain for evidence of the recent comet impact with Jupiter. I went to bed for a while and woke about 1 AM just to go outside and take a look at Jupiter again. Still no sighting of the comet impact. (Well… without taking a look at my computer and seeing when that impact spot would be visible, one can’t expect miracles.)

It was a great evening with a new scope. I woke this morning just a little tired from the loss of an hour of sleep. It was worth it. As I thought about a name for this scope while I was taking my shower, several names came to mind. Big Bertha seemed apt, because I am overwhelmed by the size of the mirror. But I have seen other scopes that REALLY are big. This one is just handy-large. I thought that Big Momma, my name for UMA could be right – after all, the second object I looked at was Mizar. Big Ben or Gentle Ben were good names. But then I thought about why I had ordered this scope – to better see the dim Hershel list objects. It was about this time that “Looking Glass” came to mind. Along with that name came Alice and her Wonderland. Those happy thoughts persuaded me. “Looking Glass” it is.

Building a Telescope

The hardest part of building a telescope is beginning.

Fortunately, I had a good reason and a good example late last winter to take on this project. There was a competition fostered by one of the forums on the CloudyNights website to build a telescope that cost less than a hundred dollars. Matt, my San Antonio astronomy friend, posted the details on our local Yahoo group. He mentioned that he had found a place to buy a 4 inch mirror and a diagonal for $40 including shipping.

On a whim, I ordered the mirror and started thinking about how to build a scope. I decided that my goal was not only to design an inexpensive scope, but one that would be easy to build too. Maybe a family or a school science club would take up plan and build one of their own.

After the mirror had been sitting in my hobby room for a month or more, I began thinking of actual plans for building a scope. It seemed like I needed to divide the project into several areas: Optics, Furniture, and Mechanics.

For the Furniture portion, I thought of different ways that I could build a simple Dobsonian scope with as little use of wood working equipment as possible. I knew that a base could be constructed much like the base of my XT10. I needed to think about a way to build an optical tube. After scouring the local hardware store, I came up short on tubes that would fit the mirror, without being way too big. I decided that the easiest way to create the tube was to make a long box with open ends using standard lumber.

Next, I started working out the optics. On a clear night with a bright moon that shone nearly overhead, I put the mirror on my driveway, just in front of my garage door. My garage faces south, so I was able to find the moon’s reflection from the concave mirror on a piece of paper that I held along the door frame. I moved the paper up and down until the image was in focus on the paper. When it was, I made a small mark on the door frame and then measured the distance from the surface of the mirror to the mark. It was 36 inches, and I knew that the optical length from the mirror to the underside of the eyepiece needed to be very close to that distance.

The mechanical distance needed to be the distance from the eyepiece to the center of the secondary mirror plus the distance from the center of the secondary to the surface of the mirror itself. Knowing that distance, I knew that the optics needed three pieces of machinery. I had to find a way to hold the secondary mirror, a way to move the eyepiece in and out to focus, and a way to columnate the secondary mirror.

For focusing, I decided that I would use the oldest and cheapest focus trick: I would have a friction fit between the optical tube and the eyepiece so that I could move the eyepiece in and out for fine focus. How would I achieve such a fine tolerance? By applying just the right number of layers of duct tape to the inside of a hole cut with a 1-1/4 inch hole saw.

For the secondary mirror, I borrowed an idea from the web: using hack saw blades to spring fit a spider into the optical tube. However, with a four sided tube as I envisioned, I would need to have a spider with four legs, each leg resting in a corner of the tube. To make the spider, I slotted a piece of PVC to receive two crossing hack saw blades. I measured the distance from corner to corner and cut each hack saw blade an inch short of that measurement. I fit a piece of dowel into the PVC pipe with a 45 degree angle cut at its end. I used some clear silicon bathtub calk to attach the secondary mirror to the angle cut on the dowel. That gave me a platform that I could move around in the tube to have the secondary under the eyepiece, and in which I could rotate the secondary to correctly reflect the primary into the eyepiece.

For the eyepiece holder, I elected to make the eyepiece hole in one corner of the optical tube box. I used a hole saw to make the hole, making sure that it was pointed straight at the far corner when I was cutting the hole. After measuring twice, I cut the hole about 2-1/4 inches from the open end of the optical tube.

I jumped past the primary mirror cell construction in my description, though it was actually the first thing I made. I cut two pieces of 2x6. One was square and one was just a little longer, so that it could be attached to the sides of the “tube” made with 1x8 standard lumber.

For the cell, I suspended the square by counter sinking 1-1/2 inch bolts in the floating square, and then placing a spring between the floating square and the cell frame. I used wing nuts to adjust the floating mirror holding square from the bottom of the scope. For the springs, I obtained a screen door spring and pulled the spring until it came a little “unsprung”. I cut the spring at three coils for each of the adjusting bolts.

The tube itself was four 1x8 pieces of lumber 3 feet long.

The base was created from several pieces of 1x12. The two rotating base boards are 11” square. I originally used an old record as my turning device, and later found that it worked even better to use three furnature glides on the bottom board turning against the record. There are two vertical pieces to the base, braced by a piece of 1x6 on the forward end.

The tube turns in altitude on two 4 inch PVC pipe caps.

A piece of pipe can be used to aim the scope, or perhaps a red dot finder can be added to the set-up.

That is a building history for the wood box scope. Since I came up with the idea in Helotes, Texas, I began calling the design the Helotescope.

My friend Matt did mostly the same design. He added a used focuser instead of my friction device. That works very well too! The picture at the beginning of this blog shows our two scopes at a meeting of the San Antonio Astronomical Association this last winter.

I have taken this scope to several public star parties. It never fails to attract some young men that look carefully at the scope. I can see the wheels turning in their minds. However, I have not yet seen the third Helotescope.