Saturday, March 28, 2015

The Design: ...and The Rest

There was an old U.S. sitcom called "Gilligan's Island" that aired in the mid to late 1960's.  It had a sort of ensemble cast and a catchy theme song that introduced the primary characters, but for the first season the song only introduced five of the seven cast-aways, ending the introductions with "...and the rest...".  There were only two actors left to introduce, but they just sort of raced to the finish and did not mention then.

I always think of this when something is nearly completed, but then sort of rushed through right at the end.  There are probably lots of reasons someone would spend a fair amount of time on 5/7ths of a project, only to rush the last 2/7ths at the end.... in my case, I've realized I just won't ever finish documenting my design choices if I write a full description of each.

When I was in the midst of making the decisions, writing the entries was a way for me to explore my own decision making process and was part of the excitement of the project.  Now that it's done, and I've been using the scope, there are other things I'm more excited about, like making the scope perform better, adding an equatorial platform and maybe some DSC's, so the final documentation of the parts that are already done been languishing.

I've already covered the reasons I decided to build rather than buy, what I selected for the size and primary mirror supplier, and my what I chose on how to hold all the bits together.  So, in rapid fire style, here is some information on what I actually ended up buying for the remaining parts, and why.

Secondary Mirror

Selecting a secondary for me was all about the tradeoff between directing as much light as possible from my nice big primary to the eyepiece, and shadowing that exact same nice big primary.  I am building the telescope for visual use, so having the entire field evenly illuminated is not as critical as it would be for imaging.  The link below really helped me think through this tradeoff and ultimate decide on a 3.1" major axis secondary.

This link also contains a super-handy table which has already calculated various primary/secondary combinations.  According to the table, to achieve 0.5" illuminated circle at the eyepiece with my 16" f/4 and secondary placement, I would need a 3.16" mirror.  Since secondary mirrors come in a few standard sizes, I rounded down to a 3.1".  This gives me a central obstruction of 3.7%.  Not too shabby!

Here is a copy/paste from my original worksheet.  The prices are several years out of date, but it shows the suppliers/options I narrowed it down to:

Antares Opticalpyrex3.11/14 p-v$180
Protostarpyrex3.11/10 p-v$195
Astrosystems.bizpyrex3.11/10 p-v$175
Astrosystems.bizpyrex3.11/14 p-v$195

I ended up going with the Antares Optics 1/14 p-v pyrex secondary, and it's performed wonderfully!


Daniel Steel at, where I purchased the structural kit for my telescope, also sells accessories for the telescope builder.  I decided on a three curved vane spider and he gave me a great price and included it in the shipment with my kit.  A curved spider seemed like a good idea, it spreads the energy from the diffraction of vanes out into a larger area, removing the "spikes" from stars resulting from the diffraction of straight vanes.

For smaller scopes, perhaps a curved vane spider is a workable solution.  In hindsight, for a scope of this size, I would have gone with a standard straight vane spider.  Overall curved vanes have more vane in the light path, so more diffraction overall, even if it's spread out and less noticeable.  Additionally, I feel like, at least some, of the collimation drift I experience as I move the scope in altitude is a result of the curved vanes not holding enough tension to keep the secondary firmly in place.  Early on I adjusted the mounting to put as much tension on the curved vanes as I reasonably could, and this helped quite a bit, but I'm still pretty sure it's angle is changing slightly as the telescope moves.

There are a number of things I want to modify about the telescope now that I've been using it for a while.  Not that it's performing poorly, just that I think it could be better.  Replacing the spider is high on the list.


The focuser is really the user facing bit of any telescope.  I knew I wanted something really solid, with a nice feel. sells two really quality brands, Moonlight and Feathertouch, and I think I would have been well served with either.  I went with the Moonlight two speed 2" focuser and it performs fantastically.  It's well made, super-solid, with a great feel as you are using the knobs.  It's got squaring adjustments, is internally baffled, comes with a nice 1.25" adapter and uses compression rings all around.  I can heartily recommend Moonlight focusers!

I did play with the idea of getting a Feathertouch with integrated Teleview Parracorr.  With an f/4 scope I probably could use a coma-corrector, and integrating one into the focuser is a clever idea.  It's also almost $1000 USD..... and coma does not bother me that much :-)


To round out the package I decided on a two finder system.  I've always liked having a zero magnification finder, like a red-dot or Telrad to get the scope roughly pointed, in combination with a magnified finder for more detailed star hopping or even observing certain extended targets.

For this scope, I decided on, in my opinion, the best zero mag finder there is; the venerable Telrad.  It's a solid design, I like the reticle indicating various FOV's and it's so common many astronomy programs and charts include it's reticle as a default.  It's also not all the expensive and dims down really nicely, something I've found lacking with some cheaper red dot finders that always seem a bit too bright, even at the lowest setting.

I had a RACI 10x50 finder from Orion telescope which performed pretty well which I ended up re-using for this scope initially.  Those of you following closely may remember a sweet 80mm finder I purchased at PATS way back in 2012.  Indeed it has been sitting in my closet all this time, as I left a crucial part back in the U.S. when I moved to Australia.  This simple $15 part cost almost three times this to ship to Australia and I could not find any local suppliers.  I kept holding off purchasing a new one, hoping I could get someone to bring it to me.

Well, finally it's happened and I have the 80mm finder, a telescope in it's own right with swappable eyepieces and a nice set of optics, mounted on my new dob.  Just last month I took it out to the ASV Messier Star Party.... and of course it rained.  I've yet to use it as a finder, but I'm really looking forward to the next new moon.

Sunday, March 9, 2014

ASV 2014 Messier Star Party

This past weekend I was able to take a day off of work, and head on out to the Astronomical Society of Victoria's (ASV) Messier Star Party.  This is an event held around the first new moon in March, at the Leonard Mow Dark Sky Site.  The LMDSS is an observing enclave maintained by the Society for the benefit of it's members... and a wonderful benefit it is!

As it so happens, about one year ago was my first visit to the LMDSS, also for the Messier Star Party.  It's been an eventful year, but I've still been able to make the trip five times or so in the intervening months.  Every time I have the chance to go out and combine two of my favorite things, camping and stargazing, it's a huge plus for me and really helps my state of mind.  Sometimes, when I'm lucky, my partner will even indulge me and come along, despite her troubles with insects.

Several times a year the ASV opens the LMDSS to the public.  This particular event, as the name implies, is ostensibly about running a Messier Marathon, although I did not meet one person that was trying one :-)  Mostly, it's a good time to catch up with members, enjoy some local wine and food from invited vendors, and take in a good night of observing.  I wanted to extend the single Star Party night into two nights of observing, so I left Melbourne around 15:00 on Friday to head up.

Friday Night

It's a very scenic two hour drive from Melbourne, but the Friday traffic extended it to three and made it a but less pleasant.  I arrived around 17:00 and was surprised to find a half dozen groups there already.  Some people had even arrived as early as Thursday!  There was still plenty of good places to camp, and the large observing field had plenty of space, so it did not take long to get everything unloaded and arranged.

The LMDSS is separated from the Melbourne basin by a bit of a hilly/mountainous feature and is quite inland, so the weather is very different.  I've been fortunate that every time I've made the trip, no matter what the weather was in the city, or when I arrived at the site, by nightfall the clouds have rolled away and left the sky clear.  Transparency will vary with humidity, and potentially bush fires, but the sky has always been clear...

Sadly, my lucky streak did not hold out, and the clouds never really left.  They would slack a bit, and open up sucker holes, then close in just when I got the scope pointed somewhere.  Shortly after dark lighting started far away from the North and lit up the clouds very consistently for several hours.  Since there was no observing to do, I setup the camera to take some shots of the beautiful, but pesky, clouds.

Lightning and Stars at the LMDSS

Once I got over the disappointment of a missed night of observing, the sky was almost hypnotic to watch and I had a chance to chat with the other sullen observers on the field.  As we were chatting, the sky opened up enough to see the Large Magellanic Cloud, so I setup a quick timelapse to capture it and the clouds.

Not the night I had hoped for, but fun and better than a day at work and a night back at the apartment!


Saturday started wonderfully, there was enough cloud cover to keep things cool so I could sleep in, and I had a great view of some ravens as I made and ate my breakfast.  

A couple of Ravens mucking about

The rest of the day passed somewhat slowly, I spent a lot of time pouring over and annotating a Souther Sky Messier Marathon list from the (Grupo de AstrĂ³nomos Mendocinos Aficionados).  While not an Australian club, they share roughly the same latitude as Melbourne and thus the same sky.  Since some of the Messier objects are simply not viewable from the southern hemisphere, and many are very difficult, this modified list was a big help.  

My plan was to run the marathon on Friday night, sleep in on Saturday to catch up, and then have an early night of observing on Saturday to make sure I was in good shape for work on Monday.  This would have worked out perfectly, as Saturday was the public night and it's tough to power though a long and dense observing list and do outreach at the same time.  Since my Friday plans were thwarted, I decided to work my way though the list focusing on things I may not have seen before, but not try to run an actual marathon.

As night fell, the sky opened up and it turned out to be a good night for observing.  Not perfect, the humidity in the air limited transparency a bit, but still pretty darn good as the image below shows.  This is the area to the north of Crux, the Southern Cross, and rich portion of the Milky Way which includes the Eta Carina nebula.

Milky Way - Eta Carinae Nebula

After checking with some folks around me, I setup the camera for what I hoped would be a nice timelapse of the same basic region.  The movie below starts in the same basic region as above, and ends up with Crux in the top-left quadrant of frame.

I did manage to log some actual observing, although I did not make it very far through the list.  Items in bold are new objects for me:

SMCSmall Magellanic Cloud - Irregular Galaxy
0362Globular Cluster in Tucana
0104Globular Cluster(47 Tuc) in Tucana
1316Radiogalaxy in Fornax
2168035Open Cluster in Gemini
7078001Crab Nebula
2068078Bright Nebula in Orion
1976042Orion Nebula
1982043Orion Nebula
1904079Globular Cluster in Lepus
Globular Cluster in Columba
LMCLarge Magellanic Cloud
30 DoradusTarantula Nebula
2632044Beehive Cluster

It was a great night, and I ended up splitting my time between observing and socializing with the public and other club members setup around me.  Sometimes I enjoy the solitude of a night of observing, and I used to get this when I would observe from my cabin in Joshua Tree, California. Sometimes it's nice to share the experience with others, and this is what most of my experiences at the LMDSS have been like.  Each one is a mini star-party, and there are always other people observing and sharing the sky.

Saturday, December 7, 2013

Done! : 490 days, One Scope, Few Posts, and First Light

490 Days, One Scope

For those of you who may have joined us recently, this blog is called One Year One Scope because that was my plan.  You can read all the details here, but the short of it is I wanted to buy/build/find a new telescope in one year.  Well, here it is 490 days (1.34246 years) later and I have something like the better scope I set out to build.

So I missed my one year goal, but considering I moved to Australia in the interim, I'm actually pretty pleased.   It took a while to ship the parts to Australia once I realized I was here long term, building the scope in my apartment was challenging, and works has been a bit crazy.  Progress was definitely slow....But the telescope is done, and after using it for one night, I think it's pretty darn good, with the potential to be a lot better.

Few Posts

Looking back I've not posted anything for eight months.  Terrible, terrible.  Some of that time I had little to report, the scope parts were sitting on a boat, or sitting in a corner and I was otherwise occupied with life.  However, I've been actively building the scope for just about four months.  I could have posted a bunch of work in progress stuff, but my propensity for order held me back...

I had this orderly, and seemingly wonderful, plan for this blog when I started.  Every post would be an organized signpost along the journey, and it started off well.  I figured out what I wanted, listed requirements, figured out a budget, decided to build, worked out some details of the design. You can check it all out on the right hand side there.  It was nice and tidy.

Then things sort of got messy.  I did research, made decisions and  found opportunities to get specific parts before I could write posts detailing the process.  Each time I wanted to post about some new milestone, I thought about all the other stuff I should post about first, so that everything would be a nice, tidy narritive; 'Well, I can't really post about buying the secondary mirror before I post about secondary mirror sizing...'.  So I ended up writing very little.

Now that It's done there are definitely things I am going to share, but if I could have gotten over my desire for orderliness, I could have probably documented a lot more of the process, as it happened, for myself and anyone else who was interested.  Hopefully, I've learned my lesson; A somewhat temporally disorganized post that actually gets posted, is better than the perfectly ordered post that never does

First Light

It's with this lesson in mind, that I'm posting about my first impressions of the telescope even before I've covered what I bought for all the parts, and how I built it.  I will follow up with all that for anyone who's going to start a similar journey (and I really think you should!) but if I keep waiting to get it perfect, it will never come.

That's me and the Telescope

Last night I went out to the yearly ASV Star-Be-Cue party at their dark sky site about 150km north of Melbourne.  I was racing all week to finish the scope up, and I did not complete the assembly until Saturday morning.  The final details took longer than I hoped and I was on the road a bit late, but I arrived by 5:30 and had plenty of time to setup the telescope and wait for darkness.  It was a great night of observing, and I'll definitely post more about it, but here are my first impressions.

The View is AWESOME: There is a lot of fine tuning to do, but the views really blew me away.  The Orion and Tarantula nebulas were incredible, with lots of fine detail visible.  I came back to them several times and I spent a good part of the night just taking them in.  47 Tucanae with the 13mm Nagler was resolved to the core with pinpoint stars.  It was really breathtaking.

The motion is good, but could use work: It moves well, but it takes more force than I would like and it's not balanced in the altitude axis.  Like most scopes, this one will take some tuning.  The design is solid, and I think with some balancing, a couple of minor position changes of the teflon pads and a bit of wax, it will be smoooooth and easy.

The scope is large, but manageable: I opted for the 'Easy Transport' option when I ordered the kit from DobStuff and I'm glad I did.  Since I don't own a car, I use a car share service and this time there were no larger cars available.  Breaking the scope down I was able to pretty easily fit it into the Hyundai i30 hatchback I had reserved.  This is along with my camping gear, food, and my C6 with a surveyor tripod.  The optical tube, even when shortened, can be a bit unwieldy due to the weight of the mirror, but it's actually easier than I had imagined.

Assembly and setup and collimation is pretty easy: It takes maybe 15 minutes to unload and setup the scope.  There are no tools required and almost everything is captive.  There are three bolts that are loose which I'll need to figure out a good way to keep track of, but everything else is large assemblies.  I sprung for a laser collimator since I knew I'd have to do it every time I setup, and it made the job relatively painless.

I'm going to be busy: On the way home I thought of a half dozen changes I want to make right away.  Most are minor and not a reflection on the kit, but rather my build of it or my personal preferences.  I think I can make it through a large portion of them before the next new moon when I hope to take the scope out again.  Visually, It already performs like a champ, but I think these few things will really improve my comfort using the scope.

I'm really looking forward to the first weekend in January when I can take the scope out again.  Until then, Clear Skies to everyone!

Tuesday, April 2, 2013

One Year One Scope - Now in Australia

A Lot Can Happen in a Year

I posted my first entry here on August 5th, 2012, just about seven months ago.  This blog was started as a way to record and share my efforts to build My New Telescope and my plan was to do it in one year.  A few weeks before that first post I was at the Golden State Star Party (GSSP) and I decided that the next time I attended, presumably in 2013, I would have a new telescope.  In fact, I had grand dreams of attending several summer star parties; GSSP, the Oregon Star Party, Calstar, maybe even the Riverside Telescope Makers Conference in May if the telescope was done early enough.

For a while, I was completely on track.  I ordered a mirror that should have been done around February, bought a kit that was finished in November and started on research for all the remaining parts.  There is a good chance the scope might have been completed right around this time, actually.  However, all of that changed when my work asked me to go to Australia for a few months.

Australia is Great

Well, I've been in Melbourne, Australia for over four months now, and it's wonderful.  The city is great, I've joined a local club and I even got out for some observing recently.  Originally, I was going to be back in Los Angeles around the end of May.  It would have been tight, but I probably would have made the GSSP.  Then the movie I'm working on got pushed a bit, and more work came in, which is fantastic, so I agreed to stay through September.  Obviously, this doomed any hope of actually completing my telescope in one year.

Fortunately, in more ways than one, my work offered me the chance to move to Australia long term.  How long term is sort of up to me, but it's going to be at least several years, so it's pretty long term.  This is exciting for two main reasons; First, I really like Melbourne and it's exciting to think about settling into a new city half way around the world... Second, in a strange turn of events it means I might actually make my One Year deadline.... Just in Australia.

Wrap it up and Ship it Out

After deciding that I'm moving here for the duration I started putting together plans to ship some things out here.  Along with two of my co-workers, who are moving out here, I arranged a shipping container from LA to Melbourne.  It's going to be nice to be able to keep a lot of my furniture and there should be room for all my clothes and other miscellaneous things.

Of course, among those things will be all my astronomy accessories, including my telescope kit!  Dennis from finished my kit late last year and has been holding on to it for me awaiting my return.  This week he was kind enough to ship it out to my apartment in LA so it can be included in the container.  I've also been accumulating other parts that I need to complete the scope.  I should be in good shape when everything arrives in six to eight weeks.

The one big piece missing is my primary mirror.  Shortly after I came here to work, Terry Osahowski contacted me with a status update on my mirror.  At that time I figured I would not be back for several months, so I told him to take his time and he shuffled some other work in front of mine.  I've contacted him recently about my relocation and the possibility of shipping the mirror to Australia.  If all goes well, it should arrive around the same time as my shipping container.

So Will I Make It?

Right now it seems like I might have everything in my hands at the start of June.  That gives me just about one month to put everything together and get that new scope under the stars.  This is probably just doable, as I think a few solid weekends of work will get me there.... but... One of the reasons I set the one year deadline was to make it to the GSSP with my new scope, which is almost certainly not going to happen.

What I will aim to do is make it to the Astronomical Society of Victoria dark sky sight on the same weekend as the GSSP, which is July 7th this year.  This is the date of the new moon in July and should be a great time to try out the new scope under new skies.  I just hope it's as portable as I think it will be as I'll be stuffing it into a rental car and driving 150km!

I'm really going to miss going to the GSSP, it's been the highlight of my astronomical year since my first visit.  There must be some big star party near Melbourne I can schedule in to fill the void.  Let me know if you are a local astronomer who can recommend a local event.

Wednesday, March 13, 2013

ASV Messier 100 Party Observing Report

Welcome Back

After a very long hiatus, I finally had a chance to get back under the stars this past weekend.  I've been in Melbourne Australia for just about four months now, and I had not been observing for at least a month before I left California. All together it has been almost half a year.  Being under the stars, a new set of stars for sure, felt wonderfully familiar and exciting.

I'd been hoping to get out and do some observing for some time, but a variety of circumstances from work to brush fire warnings had kept me locked under the light dome of Melbourne.  Over the long labor day weekend my opportunity finally came in the form of the Astronomical Society of Victoria (ASV) Messier 100 Party. 

Welcome to the ASV Messier 100 Star Party

The Messier 100 party (I'm assuming only 100 are visible from in one night from this far south, but I'd like to check on this) is a yearly public event hosted by the ASV at their Leon Mow Dark Sky Site (LMDSS).  It's located roughly 150km (93m) north of Melbourne in some kind of natural preserve area, and is easily darker than my usual observing site in Joshua Tree 240km (150m) east of Los Angeles.  For me and my partner it was a short and scenic two hour drive in a rented car.  This was our first time driving in Australia, but after riding a bike here for several months it was not too unnerving to take to the (opposite side of the) road in a car.

Memorial / Dedication marker for the LMDSS

We arrived a bit before dusk and the camping area was already fairly full as the site was open to the public on this night.  It took a while to find a spot and setup camp, but it's a beautiful area that is pretty well laid out.  There is a clubhouse with some bunks and a kitchen along with toilets and showers.  I was itching to get out to the observing field and setup my kit before dark.  Sadly, I was in such a hurry to setup camp and get my gear unpacked that I forgot to get any pictures that evening.  Every picture in this post is from the following morning and things had already thinned out a bit.

180 Degree panorama of our campsite

When I went home for Christmas I brought back my C6 Travel Kit and this is what I packed with me for this outing.  It's a nice scope; In it's travel configuration it's a bit under mounted, but still rather functional.  I grabbed the bag and headed for the observing field. 

Road to the Visual Observing Field

There were already roughly 20 scopes on the field, with a large section in the center reserved for the club's 25" Obsession which had yet to be setup.  The horizon was not perfect, there are several large trees surrounding the site that are being preserved as part of a nature reserve, so I tried to pick my spot carefully.  If you are not at one side or another of the field visibility is good above 15 degrees, so all in all it's a nice spot.

360 Degree panorama of the Visual Observing Field

I picked what seemed like a good spot and setup my kit.  It went pretty quickly and the telescope was in reasonable shape for having travelled almost 13,000km in the belly of a plane.  The travel kit fits in a carry-on suitcase, and I've flown with it before, but there are weight restrictions for carry on bags that have never caught me before.  On my last flight they weighed all the carry-ons and I ended up needing to check my bag.  I was pretty happy when I retrieved it from the baggage carousel and it was all in one piece.

As you can see from the picture below it's mounted on a robust photo tripod, but it's still not the normal surveyors sticks I use at home.  I don't extend the legs to help with the shaking, but it makes for a very low setup.  The foldable stool works well for most angles, but observing near the zenith can be a real pain.  Once I was all setup I went back to camp to have some dinner and await the darkness.

My observing setup

Brand spanking new australia made camp chairs

The Sky at Night

Right as we were finishing dinner we could hear someone at the clubhouse announcing that the Sky At Night talk would being in a few minutes.  We walked over and gathered around a group of perhaps 50 people for a tour of the night sky.  The weather had been cloudy all day, and there were still patchy clouds around as the night darkened, but the presenter (Perry Vlahos, I believe)  managed to work around them and point out some of the key constellations of the southern sky.

After a few minutes my eyes adapted a bit and the dusk faded enough for me to get my first look at the large and small Magellanic clouds.  There were both obvious and easily visible with direct vision.  The large cloud is almost as bright as parts of the Northern Milky Way, and in binoculars it's easy to see some brighter and darker regions.  The small cloud seemed to me like an elongated spiral galaxy viewed through a telescope, but it was right there in the sky.  The Andromeda Galaxy is the closest object I can compare it with, but Andromeda is much smaller and dimmer in the sky.  I was really pleased to be out observing again.

Once Perry had oriented us, he pointed out a few nice binocular objects, mainly open clusters, but also one or two globulars thrown in.  They went fast, and I was more interested in looking than logging so I'm not entirely sure what I observed in that first hour or so.  One think I could see is that the Southern Milky Way is rich with wonder indeed!  I'm not sure if it's just that there is so many NEW things to see, or if there are just more of them, but scanning the plane of our galaxy with binoculars seemed to reveal a train of open clusters, rich star fields, and faint nebula.

As the tour was wrapping up the clouds cleared from the western horizon and Perry took the opportunity to point out Comet Lemmon low in the sky.  I could not find it with the naked eye, but it was easily visible in Binoculars.  It had a distinct and visible tail along with a tight nucleus and I tried to note it's location in the sky so I could return to it later with the telescope.

After the tour I returned to my scope and decided to run down a list I had hastily cribbed from the Astro League Southern Sky Binocular Program.  While cooking dinner I had scrawled down most of the globulars, galaxies and nebula on the list.  I was really not as prepared as I would have liked to be, particularly considering how little I knew of the sky, so this list seemed like a fair place to start.

My First Southern Observing Run

First on the list was 47 Tucanae (NGC 104), a big and bright globular cluster.  This one is nestled close to the SMC and is actually pretty easy with the naked eye.  It appears definitively non-stellar and I was surprised at how bright and obvious it was.  It gave a great view through the scope, with a nicely condensed core and good resolution of the edges with my 13.5mm.

I moved on next to Omega Centauri (NGC 5139), one of my favorite, but usually very elusive, globulars.  From just about everywhere I've observed, this one is low on the horizon in the murk, but still looks beautiful.  Even though it was early, and would climb much higher later in the evening, it was already close to 40 degrees above the horizon and very visible.  In the scope it resolved almost completely into a riot of stars.  It is pretty massive by globular standards, and is not strongly condensed so it gives a really nice view.  Seeing this somewhat familiar object in a whole new way really made me feel like I had a lot of wonderful experiences ahead of me observing from the southern hemisphere.

Clouds were starting to be a bit of a problem, and I had a hard time orienting myself under the unfamiliar sky with only partial views.  I decided to go grab a peek through the club's big gun, the 25" Obsession.  They had it pointed at the Orion Nebula and I thought it would be a kick to compare the view with my C6.  I climbed the ladder and looked through the eyepiece.  They had a good bit of magnification right on the Trapezium.  All five main stars were easily visible, and a nice bit of dark nebulosity carving out the edge of field.  My 7mm eyepiece was still back home, so I could not muster as much magnification on my C6, but it was still very nice view.  I actually enjoyed the extra context and the nebulosity is bright enough to be beautiful in any scope.

Since it seemed like an easy catch, I turned my attention to the Tarantula Nebula, an HII region in the LMC.  It's easily identifiable in either binoculars or a finder scope as a knot of increased brightness embedded in the diffuse glow.  Through the scope it showed a nice bright nebulosity that showed some nice variation and subtle detail with continued viewing.  I'm looking forward to visiting this again with a wider variety of eyepieces and maybe a filter.  Certainly I'd love to have a long look with a larger scope!

As the clouds continue to occlude various parts of the sky, I tracked down two more globular clusters, NGC 362 and 419 in Tucana.  I was searching for 362 specifically, but ran across 419 as a nice surprise.  They were both quite nice, with 419 much dimmer than 362 but still easily identifiable as a globular.

By this time most of the sky was clouded over, but through a small opening to the east I could see Saturn had risen, so I decided to end my night with my favorite planet.  The view was not fantastic, the combination of thin clouds and low altitude presented a low-contrast and roiling view, but it was still very satisfying.

The total tally was four globulars, two galaxies (LMC/SMC), two nebula one planet, seven meteors and one flyover of the ISS.  All in all a really wonderful first night and more than I hoped for considering the weather and my inexperience with this new starscape.

Packing Up

I decided to leave the scope on the field and pack it the next morning.  It's a little finicky to get everything back in the suitcase and I felt secure at the club site.  I walked back to bed and had a pretty good sleep in my new tent, with new sleeping bag, new pad... basically new everything as I did not bring any of my camp gear from the US.

The next morning I woke up pretty early and went out to retrieve my scope.  As I was so excited to get some observing in the previous night, I took this opportunity to grab some pictures and really get a good look around.  The LMDSS is a great site, and I'm really looking forward to getting my membership so I can use it on a regular basis.

The LMDSS is situated amongst some beautiful bushland

There are actually three fields, one for visual, one for astrophotography and there is an additional section for radio astronomy.  I did not have a chance to get a good look at the radio astronomy gear, but I wandered out to the photographic field to see how it differed from the visual field.

Wide view of the Photographic Field 
Four of the dozen or so piers in the Photographic Field

It's set further away from the clubhouse, to avoid any light contamination, and has a good number of piers for mounting rigs.  There is also a dome which houses the clubs permanent astro-imaging setup.  Next time I'm definitely bringing my DSLR for some wide field astrophotography.

I wandered around a bit more and finally decided it was time to pack up my kit.  It was quick work in the daylight but I was glad I did not attempt it at night.  I have to really take everything apart and its important to make sure everything is packed well to avoid any damage.  In the picture below you can see the scope with the mount below it in frame and the tripod above.  The blue bag is for my 8x50 finder and the green fingerless gloved to the lower-right hold and cushion the star diagonal.  The whole thing is topped off with some bubble wrap tucked between all the metal parts and it's zipped and strapped shut.

The C6 travel kit, all packed up

My C6 travel kit is airline carry-on friendly, except for the weight

Let's do it again

After such a long time it was so refreshing to be observing again.  It made me crave another outing as soon as I can muster it.  I've applied as a member to the ASV and I expect to get my membership approved shortly which will allow me access to the site almost any time.  If my work, finances, and the weather cooperate I could observe once or twice a month around the new moon and I'm really looking forward to it.

Anyone have any suggestions for what should be on my next observing list?  Here's hoping for clear skies for all the observers out there.

Thursday, December 20, 2012

The Design: Structure

All Systems Go!

A month or so before I left for Australia to work for a while, I placed an order for my primary mirror.  It's a 16" F/4 from Terry Ostahowski which should be ready sometime in March.  With this key decision out of the way, I can pretty much order everything else for the scope as my funds and time allow.

One of the key reasons I decided to build my own telescope was so that I could choose exactly which parts met my particular balance of cost, quality and portability.  I have a good handle on the basic components needed, and some time to figure out exactly which specific part will best serve my needs.  After the mirror, the next thing seemed to be the overall structure... the stuff that would hold all the other stuff together.

The Criteria

Just like the overall criteria for my new scope, the structure itself needs to be portable, and economical, but there are a few more specific requirements:

  • I want it to be as small and light as reasonable to firmly and stiffly support the optical system.  
  • Ideally it will be quick and easy to take apart and put back together.
  • It should have great motion;  Pointing a scope is a big part of using a scope and stiff or irregular movement on either axis can be a frustration.
  • Like most things, being aesthetically pleasing is a plus.
  • Of course it should be as inexpensive as possible while meeting the above criteria.
Any structure will be some compromise of all these competing criteria.  Some of them, like 'great motion' are tricky to evaluate without seeing one in person.  I've already decided that some variation of the Dobsonian mount.  This is mainly due to my desire for ease of use, but also helps a lot with the budget.  An equatorial mount for a 16" telescope would pretty much consume it entirely.

The Options

The first option is to built it all myself.  This sounds like a fun project, I do have some woodworking experience, and there are good plans of various designs available on the Internet.  In theory, it would be the least expensive monetarily, but would take a large amount of time.  Practically, I don't have a wood shop so I would need to purchase quite a number of fairly expensive tools to really do the job.  There is also a good chance I would not get it anywhere near right on the first try, which would mean putting up with something sort of usable, or spending the time and money to re-do it.... maybe more than once!

Although building from scratch was initially appealing, after a bit of thought, the option of a commercial kit seemed like a much better choice.  I'd love to be able to say with pride that I crafted this great telescope by hand, but even if I produced the structure, I knew I was not going to make the mirrors, focuser, cell, or any of the other pieces that go into a working telescope.   Some sort of kit really fit in with my plan for the scope; To assemble it from the specific pieces I feel meet my criteria best.

Besides,  I already had read about a great kit option, so I knew they were out there.  Even though I was pretty excited about the kits, I wanted to see what other options were out there.  My search was not exhaustive, but I came up with a few other options:

  • Obsession Telescopes:  I heard rumors that one could purchase some or all of a kit from Obsession, but I could not really find any information on this.  If they do sell them, I bet they are pretty nice, and rather expensive.  
  • AstroSystems Telekit:  This seems like a nice kit, and it actually comes basically complete with spider for the secondary and a mirror cell.  The cost for a 16" kit is $1670, which after subtracting my budgeted cost for spider ($120) and primary cell ($250) is $1300.
  • Hubble Optics: As indicated in this review Hubble Optics will sell you the structure of their ultra-portable dobs.  The price is listed in the review at $1195, which includes the spider and cell, I assume.  This is a bit better than the AstroSystems, and is very lightweight.  I had researched Hubble Optics as a potential supplier of the entire scope, but it seems there is some work to be done to make their scopes really perform, and I'm looking for something solid, even if it weights a bit more.
  • DobStuff offers kits in a variety of sizes and configurations.  By default it's the structure only, but they also produce mirror cells and sell various lines of parts.  Kits include all the wooden elements, the strut poles, and bearing surfaces (ebony star/teflon) required to build the scope.  All I would have to do is sand, finish, and assemble.  The 13"-16" strut kit is $696.  I saw a few in action at the Golden State Star Party and was impressed.

The Decision

DobStuff kits were high on my list when I started this project.  In a way, it's sort of what inspired it by getting me daydreaming about building a large dob; Knowing I could get the precut parts to assemble made the whole enterprise seem doable.  After exploring the options above, I sent an email to Dennis Steele inquiring about prices and lead time.

He was very helpful and the prices were as quoted on the site.  It also turns out his workshop is near my primary observing locations in Joshua Tree, CA, where the scope would be built and spend most of it's time.  Graciously, he agreed to allow my to pickup the scope from his shop to save some shipping.

I placed an order for a 16" strut kit with the easy transport option for even more portability.  While I was communicating with him I also found that he produced nice aluminum floating mirror cells as well.  I'd already done a fair bit of research on mirror cells, which I'll describe in another post, and I felt his price/quality/design made sense, so I added a mirror cell to the order.

I believe the initial lead time he quoted was something like 4-6 weeks, which seemed fine since my mirror would take four months anyway.  This would still give me plenty of time to work on finishing and assembling the structure before the mirror was ready.  Turns out, he was able to piggy back my order with another 16" kit and cut the parts all at once.  This shortened the lead time to just a week and a half!

On October 20th, Dennis sent me an email with a picture of my completed kit, ready for pickup!

DobStuff 16" kit with mirror cell.  Strut poles are included but not pictured.

It was around this time that I learned I would be going to Australia for several months.  Exciting, but a bit of a bummer at the same time.  I was really looking forward to sanding that bad boy up nicely and figuring out what stain/finish I wanted to use.  When I emailed Dennis to let him know I could not pickup the kit as planned and to arrange for shipping, he kindly offered to hold the kit for me as long as I needed for no additional cost.  That's great customer service!

Current Status

As of now I have almost 2/3rds of a telescope. budget wise at least.  Here is my updated budget with a few the few things I've ordered slotted in with actual pricing.

16" Primary Mirror$2450Terry Ostahowski 16"
Secondary Mirror$220
Mirror Cell$200DobStuff Flotation Cell
Structure$700Dob Stuff 13"-16" Kit

For anyone keeping track, this is about $1200 more than my original budget.  This is pretty much due to my mirror choice.  I had originally planned on going with a more mass produced JMI 16" f/4.5 mirror with secondary for only $1439, which is a very good price.  However this would have made the scope too long and put the eyepiece out of reach for me when pointing towards the top of the sky.

I could have gone with a smaller mirror, and therefore a shorter scope, but once I left the JMI mass produced mirror behind, I was in custom territory and the prices went up considerably even for smaller mirrors.  I ultimately decided to spend more now so I would not be as tempted to upgrade again later or regret that I did not get the scope I really wanted after all was said and done.

So that is where the project stands.  I have a mirror on order, perhaps even being ground by now, a finished DobStuff kit waiting to be picked up, and me out of the country.  I knew waiting would be tough, and being on an overseas adventure of sort has made the time go by more quickly, but I am anxious to get started.  I miss observing in Joshua Tree and knowing I could be working on the scope during the day, and observing at night over the holidays, makes it all the tougher to be away.

I hope the holidays find you in good spirits and provides some wonderful winter observing opportunities.  Clear skies and warm fingers!

Saturday, December 15, 2012

The Geminids and The Astronomical Society of Victoria

So yeah, hmmm.... it's been a while since I posted.  Looks like it's been almost a month since my last post, and that was just a quick note about moving to Australia for a while.  If you discount that, it's been almost two months.  It's been a busy time, but I'm finally feeling settled into the new city and the job duties are smoothing out, so I'm hoping to write a bit more.

I've certainly not stopped dreaming about astronomy, or my future telescope, but dreaming is about all I've really been able to do.  I'm under a whole new section of sky, with so many and varied wonders to be seen, and I've not been able to take advantage of it... yet.  A few things have been lacking so far, Time, Equipment, and Knowledge.

Time and the Geminids

I think the time issue will  only get better from this point, at least for a while.  The new studio I'm here to setup is really coming together; I'm now usually free on the weekends and I'm not working very late in the evenings.  In fact, last Tuesday, the sky was very clear, the moon was gone, and I took my new Southern Skies edition of the Night Sky out on a walk.

I did not get anywhere very dark, mostly just around my hotel, ducking into shadows to avoid street lights.  There is a park nearby I've got my eyes on, it's walking distance, and is large enough to at least offer some relief from local light sources... maybe next time.  On my short excursion I was at least able to look at the sky and try to orient myself.  Even fairly close to the center of Melbourne, there are still significantly more stars visibile than in Los Angeles.  I'm going to chalk it up to less particulate in the air, and about half the population density.

There are some familiar sights here, I spotted Orion almost immediately, but it took me a minute or two to realize what should have been obvious.  He's upside down.  At least from the way I'm used to seeing him.  The constellation was low on the North/East hoizon, and his sword was hanging 'upwards' towards the zenith pointing the way to a whole area of sky completely unfamiliar to me.  It was strange to think that the rest of the sky I'm familiar with is down below the horizon in the direction of his, now upside down, head.  

My attempts at finding constellations were not all that successful, this first time out.  I'm hoping to spend some more time studying the sky next week if the weather cooperates.  Even though it was a short observing session, from a terrible location, I was rewarded with one gem.  A very bright, and fairly long lived, Geminid!

At least it seemed like a Geminid.  It was several days before the peak of the shower, but it seemed to be going the right direction, in the correct area of sky, so I'm pretty confident.  It was surprising to me considering I was a few days early, it was pretty early in the evening, and I was under light polluted skies.  Under a dark sky, I imagine it would have been awesome.


I have several potential solutions to this one.  First, as I came to realize by taking the time to actually go outside and look up, eyes are pretty good on their own.  There is a lot for me to observe with the standard issue equipment.  There are whole new constellations and wide starscapes to learn and appreciate

Second, I found an optics shop that has what looks to be a decent pair of binos at a resonable price.  I've not found many reviews, but the few I have found are positive.  New binoculars have been on my list for a while, and I'd love to get under a dark sky here and try them out!

Third, when I return to Los Angeles for the holidays in about a week, I'm going to come back with my C6 travel kit.  At 6" (152mm) in diameter the scope is smaller than my workhorse XT8, and much smaller than the 16" (406mm) I'm working on building.  I'll also have to travel light, with the collapsable photo tripod and a limited set of eyepieces and accessories, but it will still be a heck of a lot more kit than I observed with for years.  I expect great things from that little scope!

Knowledge - Enter the ASV

To tackle the last item I'm going to join the Astronomical Society of Victoria (ASV), which is the local astro club here in Melbourne.  The way things stand right now I'll be here for 4 months or so after the new year.  That's maybe 8 weekends of good dark sky observing when the moon won't be an issue.  Weather might cut into that number even more, so it's important I know where to go to observe, and what the "Can't Miss" objects are.  I need to meet people who know the geography and the sky.  Also, maybe they can give me a ride... driving on the left is a little intimidating.

Joining an astronomy club has been on my todo list for a long time.  In Los Angeles, my work schedule and lack of automobile always seemed to interfere with getting to any of the local club meetings to check them out.  By a wonderfully strange set of coincidences, here in Melbourne, I'm staying a block or two away from the regular meeting place of the ASV, and my work runs from 8-6, rather than 9-7.

I missed the meeting in November due to work and ignorance of the location, but I was able to attend the December meeting last Wednesday.  Right before the meeting was scheduled to start I found the room in the National Herbarium and rushed in.  There were something like 50 people in attendance and the meeting started promptly at 8:00pm.

The president of the club started with some announcements about committee memberships, meeting schedule changes and information about the yearly Star-Be-Cue they hold at their dark sky site during the new moon in December.  He then went on to describe the building of a wooden hybrid tripid/dobsonian mount he built for his 6" refractor.  It was a very interesting presentation and hearing about it made me yearn for the chance to get started on my 16" scope.

Being the last meeting of the year, the majority of the time was dedicated to slideshows and videos from the last year's events.  I could not have picked a better time for my first visit!  It was a fun and fascinating to hear about the events the ASV has sponsored including monthly star parties, a viewing of the transit of Venus, and the total solar eclipse visible from the northern tip of Australia.

A few of the recaps included wide field, time lapse photography of the sky from their dark sky site.  It's only about 1.5 hours from the city, but judging from the video, it's got much better skies than my normal dark sky site 3 hours from Los Angeles.  Even though Melbourne is not all that far south, at 37 degrees latitude, they had a strong Aurora during one of the most recent star parties.  Sadly, this is very uncommon, so I'm not likely to see anything like it while I'm here.  Still, it was beautiful, even on the time lapse.

When the meeting was breaking up I had a chance to introduce myself to the club president and speak to him for a few minutes.  He, like everyone I met, was very friendly and enthusiastic about both their club and the night sky.  Before attending the meeting I was somewhat apprehensive, but it was a wonderful experience to be around so many people with a common interest.  I look forward to attending again in January.

When I get back into Melbourne after my holiday trip home, joining the ASV is first on my todo list.  For a $70AU membership fee, I'll have access to their dark sky site and, more importantly, a group of very knowledgable people to help me make the best of my observing time here in Melbourne.  I'll probably end up renting a car for the trips, but it will be nice knowing that I have a dark and friendly place to head to.

Attending the meeting also showed me what I am probably missing by not making the effort to make it to one of the local Los Angeles clubs.  When I get back I'm definitely going to find some way to make it work for me.  If you have not at least explored one of your local astronomy clubs, I really suggest you do.  You might enjoy it as much as I did.

My next post will definitely return to my telescope build, I've got some exciting new via email to share!