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Category Archives: astrophysics

Fixing a dull ‘Personal Solar Telescope’

12 Friday Aug 2022

Posted by gfbrandenburg in astronomy, astrophysics, monochromatic, optical flat, Optics, science, teaching, Telescope Making

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ATM, Coronado, filter, Hydorgen-Alpha, Meade, Optics, PST, solar filter, Solar telescope, Telescope

A decade or so ago, I bought a brand-new Personal Solar Telescope from Hands On Optics. It was great! Not only could you see sunspots safely, but you could also make out prominences around the circumference of the sun, and if sky conditions were OK, you could make out plages, striations, and all sorts of other features on the Sun’s surface. If you were patient, you could tune the filters so that with the Doppler effect and the fact that many of the filaments and prominences are moving very quickly, you could make them appear and disappear as you changed the H-alpha frequency ever so slightly to one end of the spectrum to the other.

However, as the years went on, the Sun’s image got harder and harder to see. Finally I couldn’t see anything at all. And the Sun got quiet, so my PST just sat in its case, unused, for over a year. I was hoping it wasn’t my eyes!

I later found some information at Starry Nights on fixing the problem: one of the several filters (a ‘blocking’ or ‘ITF’ filter) not far in front of the eyepiece tends to get oxidized, and hence, opaque. I ordered a replacement from Meier at about $80, but was frankly rather apprehensive about figuring out how to do the actual deed. (Unfortunately they are now out of stock: https://maierphotonics.com/656bandpassfilter-1.aspx )

I finally found some threads on Starry Nights that explained more clearly what one was supposed to do ( https://www.cloudynights.com/topic/530890-newbie-trouble-with-coronado-pst/page-4 ) and with a pair of taped-up channel lock pliers and an old 3/4″ chisel that I ground down so that it would turn the threads on the retaining ring, I was able to remove the old filter and put in the new one. Here is a photo of the old filter (to the right, yellowish – blue) and the new one, which is so reflective you can see my red-and-blue cell phone with a fuzzy shiny Apple logo in the middle.

This afternoon, since for a change it wasn’t raining, I got to take it out and use it.

Verdict?

It works great again!

Hopewell’s Ealing Mount is Working Again – After 8 Months!

09 Saturday Jul 2022

Posted by gfbrandenburg in astronomy, astrophysics, Hopewell Observatorry, Optics, Telescope Making

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Android, Arduino, DM524, ealing, electronics, MaxESP, motherboards, OnStep, signal, stepper drivers, Stepper Motors, TB6600, Telescope, Telescope drive

 Guy BrandenburgJul 6 

 At long last, we have finally got the venerable, massive Ealing telescope mount at Hopewell Observatory working again, after nearly 9 months, with a totally different, modern, electronic stepper motor drive based on Arduino.

My first post to the OnStep group ( https://onstep.groups.io/g/main/message/37699 ) was on October 21, 2021, over eight months ago. In it, I wrote that I had decided to give up trying to fix the electro-mechanical synchronous drive and clutches on our Ealing-Byers mount at Hopewell Observatory, and asked the folks on the OnStep message boards for help in choosing the best OnStep combination to drive such a mount. 

Since then, it’s been a very long and steep learning curve. We only fried a couple of little slip-stick drivers and maybe one MaxESP board. We got LOTS of help from the OnStep list (not that the posters all agreed with each other on everything)!  We ran into a lot of mysteries, especially when we found, repeatedly, that configurations that worked just fine on our workbench wouldn’t work at all when the components were put into the mount!

But now it works.

Let me thank again in particular:

* Prasad Agrahar for giving me the OnStep idea in the first place by showing me a conversion he had done;

* Alan Tarica, a fellow ATMer, for cheerfully partnering and persevering with me in working on this project for the past 8 months in many, many ways; 

* Ken Hunter for providing tons of basic and advanced advice and a lot of hardware, all for free; 

* Robert Benward for extremely helpful advice and drawings; 

* George Cushing for providing some of the original boards we used;

* Khalid Bahayeldin for lots and lots of OnStep design features;

* Howard Dutton for designing, implementing, and supporting this whole project in the first place; and 

* Arlen Raasch for bringing his wealth of trouble-shooting experience and a lot of nice equipment up to Hopewell, spending full days up there, and saving our asses in figuring out the final mysteries. Among other things, he kluged (by the way, “kluge” is German for “clever”, not clumsy) a level shifter to make it so that the 3.3 volt signals from our MaxESP3 board would actually and reliably communicate with the higher-voltage external DM542T stepper drivers that controlled the very-high-torque NEMA23 steppers, rewiring some of the jumpers on our already-modified MaxESP boards, and making the wiring look professional, and other stuff as well, thus essentially pushing us over the finish line. 

* All of the Hopewell members for supporting this project 

* Bill Rohrer and Michael Chesnes who physically helped out with soldering and wiring work at the observatory.

I plan to write up a coherent narrative with a list of lessons learned, and perhaps I can help make some of the step-by-step directions in the OnStep wiki a bit clearer to the uninitiated. Obviously I’ll need to write a user guide for this mount for the other Hopewell members.

If Alan and I had gone straight to our final configuration, this project would have been quite a bit cheaper. In addition to what’s inside the mount and control box at the observatory, we now have on hand something like this list of surplus items:

* four MaxESP boards in various stages of construction and functionality; 

* a dozen or more different slip stick stepper drivers we aren’t using; 

* four or more external stepper drivers, mostly TB6600;

* five or more stepper motors of different sizes; 

* a hand-held digital oscilloscope;

* lots and lots of wires of many types;

* lots of metal and plastic project boxes of various sizes;

* lots of tiny motherboards; and 

* lots and lots of sets of various mechanical electrical connectors (many were used, later cut off, and then ended up in the trash).

Yes, one does need spares, and yes, lots of this stuff has multiple uses, but this has not been a ‘green’ project. On the third hand, it has been extremely interesting and fun to learn all these new skills.

The final substantive changes that got the Ealing mount up and running were made during the Fourth of July fireworks down in the valleys on each side of the ridge that our observatory sits on. What were the changes? (1) switching the black and white leads from the mains power leads (they original, scavenged, cord had the white lead as Hot!) and (2) reversing the Declination motor direction. It also helped that I was not zoned-out and punchy from lack of sleep, as we had been when Arlen and I had last worked on it.

On July 4th, it at long last worked properly!

This Ealing mount’s original, labeled, built-in manual RA and DEC setting circles make it quite easy to put the scope into Home position before you turn on the power. One just loosens the clutches and moves the axes to 6:00 hours exactly in Right Ascension and 90 degrees exactly in Declination. From there, I found the OnStep system behaves very nicely. It accurately slewed to a number of bright, obvious targets of various sorts on both sides of the meridian. However, when I tried to get it to aim that night at M13, it refused, sending an error message that it was too close to the zenith for safety. And it was (altitude 87 degrees)! Very impressive – a safety feature I hadn’t even known about!

None of the objects that I slewed to was far from the center of the field of view, even when the scope slewed across the meridian. I was using an old, 2-inch diameter 50 mm Kellner eyepiece on an f/12 six-inch aperture D&G refractor.

I found that the Android app to be **much** better for initial setup than the SHC. Arlen, Alan and I all found that setting the correct latitude, longitude, UTC offset and so on from the SHC was a real brain-twister because of its unfortunately not-very-friendly user interface. Using the OnStep app on a cheap, old Android tablet made the whole initialization process very much easier and faster, especially after I let the tablet discover what time it really was from my iPhone’s wireless HotSpot. 

However, I found that the hand paddle is much better for fine-tuning of pointing and so on, because the bright display on an Android, no matter how dim one makes it, will destroy one’s night vision, and one cannot reliably feel where the directional buttons are on a flat screen while staring  through an eyepiece. Obviously, one can feel the buttons on the SHC quite well, maybe even with gloves. A joy stick would be even better…

Alan and I and the  other Hopewell members still have many more OnStep features to learn.

However: if I had known this project would take over eight months of hard work, I think I might have tried fiddling with the original Ealing clutches some more. 

Oh well, we have a mount that has much more capabilities than it ever had, and Alan and I have learned quite a bit of electronics! I’m proud of what we did!

SOLD: Antique 6″ f/14 Refractor With Good Optics Available No Longer

05 Monday Oct 2020

Posted by gfbrandenburg in astronomy, astrophysics, History, Hopewell Observatorry, Optics, Telescope Making

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Tags

achromat, brass, Carl Kiess, doublet, John Brashear, optical tube assembly, refractor, Telescope

The Hopewell Observatory had available a finely-machined antique, brass-tube 6″ f./14 achromatic refractor.

The mount and drive were apparently made by John Brashear, but we don’t know for sure who made the tube, lens, focuser or optics.

We removed a lot of accumulated green or black grunge on the outside of the tube, but found no identifying markings of any sort anywhere, except for the degrees and such on the setting circles and some very subtle marks on the sides of the lens elements indicating the proper alignment.

The son of the original owner told me that the scope and mount were built a bit over a century ago for the American professional astronomer Carl Kiess. The latter worked mostly on stellar and solar spectra for the National Bureau of Standards, was for many years on the faculty of Georgetown University, and passed away in 1967. A few decades later, his son later donated this scope and mount to National Capital Astronomers (of DC), who were unable to use it. NCA then later sold it to us (Hopewell Observatory), who cleaned and tested it.

The attribution of the mount to Brashear was by Bart Fried of the Antique Telescope Society, who said that quite often Brashear didn’t initial or stamp his products. Looking at known examples of Brashear’s mounts, I think Fried is probably correct. Kiess’s son said he thought that the optics were made by an optician in California, but he didn’t remember any other details. His father got his PhD at UC Berkeley in 1913, and later worked at the Lick Observatory before settling in the DC area. The company that Brashear became doesn’t have any records going back that far.


When we first looked through the scope, we thought the views were terrible, which surprised us. However, as we were cleaning the lens cell, someone noticed subtle pencil marks on the edges of the two lens elements, indicating how they were supposed to be aligned with each other. Once we fixed that, and replaced the 8 or so paper tabs with three blue tape tabs, we found it produced very nice views indeed!

The focuser accepts standard 1.25″ eyepieces, and the focuser slides very smoothly (once we got the nasty, flaky corrosion off as delicately as possible and sprayed the metal with several coats of clear polyurethane). The workmanship is beautiful!

Top: tiller for hand control of right ascension. Middle: counterweight bar (machined by me to screw into the mount) with clamps to hold weights in place. Bottom: detail of 1.25″ rack-and-pinion focuser.

We have not cleaned the mechanical mount, or tried it out, but it does appear to operate: the user turns a miniature boat tiller at the end of a long lever to keep up with the motions of the stars.

The mount and cradle (with size 12 feet for scale)

The counterweight rod was missing, so I machined a replacement, which has weight holder clamps like you see in gymnasiums. Normal Barbell-type weights with 1 inch holes fit well and can be adjusted with the clamps.

Unfortunately, the whole device is rather heavy, and we already own a nice 6″ f/15 refractor made by Jaegers, as well as some Schmidt-Cassegrain telescopes that also have long focal lengths. Putting this scope on its own pedestal, outside our roll-off roof, with adequate protection from both the elements and from vandals, or figuring out a way to mount it and remove it when needed, are efforts that we don’t see as being wise for us.

Did I mention that it’s heavy? The OTA and the mount together weigh roughly 100 pounds.

However, it’s really a beautiful, historic piece with great optics. Perhaps a collector might be interested in putting this in a dome atop their home or in their office? Or perhaps someone might be interested in trading this towards a nice Ritchey Chretien or Corrected Dal-Kirkham telescope of moderate aperture?

Anybody know what might be a fair price for this?

Guy Brandenburg

President

The Hopewell Observatory

Some more photos of the process and to three previous posts on this telescope.

Partway through cleaning the greenish, peeling, grimy layer and old duct tape residue with a fine wire brush at low speed to reveal the beautiful brass OTA.
This shows the universal joint that attaches to the ’tiller’ and drives the RA axis
Do you see the secret mark, not aligned with anything?
Aluminum lens cover and cell before cleaning
Lens cell and cover, with adjustment screws highlighted, after cleaning
It works!

Videos on Telescope Making from Gordon Waite

03 Thursday Jan 2019

Posted by gfbrandenburg in astronomy, astrophysics, flat, optical flat, Optics, Telescope Making

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figuring, flats, Gordon Waite, machine, optical, Optics, parabolizing, Polishing, Telescope Making, testing optics, Waite Research, youtube

Gordon Waite is a commercial telescope maker who has made a number of very useful YouTube videos on his grinding, polishing, parabolizing, and testing procedures. I thought some of my readers might be interested in viewing them. The link is here, or else you can copy and paste this:

https://www.youtube.com/user/GordonWaite/videos

Math – How Come We Forget So Much of What We Learned in School?

27 Monday Aug 2018

Posted by gfbrandenburg in astrophysics, education, History, Math, science, teaching, Telescope Making, Uncategorized

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education, engineering, forgetting, France, mathematics, scientists, USA

This was a question on  Quora. Here is an answer I wrote:

In the US, judging strictly on what I’ve seen from my time in the classroom as both a student, a teacher, and a visiting mentor of other math teachers, I find that math and science was very often taught as sort of cookbook recipes without any real depth of understanding. The recent National Council of Teachers of Mathematics prescriptions have attempted to correct that, but results have been mixed, and the Common Core has ironically fostered a weird mix of conceptual math marred by teachers being *OBLIGATED* to follow a script, word-for-word, if they want to remain employed. Obviously, if students are really trying to understand WHY a certain mathematical or scientific thing/fact/theorem/theory/law is true, they are going to have questions, and it’s obviously the teacher’s job to figure out how best to answer said questions — which are not likely to have pre-formulated scripts to follow in case they come up — and which are going to take time.

Another thing that is true is that not everything in mathematics has real-world applications in every single person’s life. I taught a good bit of computer programming (aka ‘coding’ today), geometry, arithmetic, probability, algebra, statistics, and conic sections, and in fact I use a LOT of that every week fabricating telescope mirrors to amazing levels of precision, by hand, not for a living, but because I find telescope-making to be a lot of fun and good mental, aesthetic, manual, and physical exercise. But I’m a pretty rare exception!

Most people obviously don’t dabble in math and physics and optics like I do, nor should they!

In fact, I have made it a point to ask professional scientists and engineers that I meet if they actually use, on their jobs, all the calculus that they learned back in HS and college. So far, I think my count is several dozen “Noes” and only one definite “Yes” – and the latter was an actual rocket scientist / engineer and MIT grad and pro-am astronomer (and wonderful, funny, smart person) who deals/dealt with orbital rocket trajectories. (IIRC).

In France, when I went to school there 50 years ago and in my experience tutoring some kids at the fully-French Lycee Rochambeau near Washington, DC, is that they go very deeply into various topics in math, and the sequence of topics is very carefully thought out for each year for each kid in the entire nation (with varying levels of depth depending on what sort of track that the students elected to go into (say, languages/literature, pure math, or applied sciences, etc), but the kids were essentially obligated to accept certain ideas as factual givens and then work out more and more difficult problems that dealt with those particular givens. No questions allowed on where the givens came from, except to note the name of the long-dead classical Greek, French, Italian or German savant whose name is associated with it.

As an American kid who was mostly taught in American schools, but who also took 2 full years of the French system (half a year each of neuvieme, septieme, premiere, terminale, and then passed the baccalaureat in what they called at the time mathematiques elementaires, I found the choice of topics [eg ‘casting out nines’ and barycenters and non-orthogonal coordinate systems] in France rather strange. Interesting topics perhaps, but strange. And not necessarily any more related to the real world than what we teach here in the US.

Over in France, however, intellectuals are (mostly) respected, even revered, and of all the various academic strands, pure math has the highest level of respect. So people over there tend to be proud of however far they got in mathematics, and what they remember. Discourse in French tends to be extremely logical and clear in a way that I cannot imagine happening here in the public sphere.

So to sum up:

(a) most people never learned all that much math better than what was required to pass the test;

(b) only a very few geeky students like myself were motivated to ask ‘why’;

(c) most people don’t use all that much math in their real lives in the first place.

 

 

What a Great Night!

05 Monday Mar 2018

Posted by gfbrandenburg in astronomy, astrophysics, Hopewell Observatorry, monochromatic, Optics, Safety, science, Telescope Making, Uncategorized

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Just got back from an exciting astro expedition to Hopewell Observatory with one of the other members. Great fun!

Anybody living on the East Coast in March 2018 has just lived through a very strong, multi-day gale. The same weather system brought snow and flooding to the northeast, and here in the DC-Mar-Va area, it was cut off power to many (including my mother-in law) and caused almost all local school districts to close — even the Federal Government! Two of my immediate neighbors in DC had serious roof damage.

Today, Sunday, Paul M and I decided the wind had calmed enough, and the sky was clear enough, for an expedition to go up and observe. We both figured there was a good chance the road up to the observatory would be blocked by trees, and it turns out that we were right. My chainsaw was getting repaired – long story, something I couldn’t fix on my own – so I brought along work gloves, a nice sharp axe, loppers, and a 3-foot bowsaw. We used all of them. There were two fairly large dead trees that had fallen across the road, and we were able to cut them up and push them out of the way.

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However, there was a large and very dangerous ‘widow-maker’ tree (two images above) that had fallen across the road, but it was NOT on the ground. Instead, was solidly hung up on the thick telecommunications line at about a thirty-degree angle to the ground. The power lines above it didn’t seem to be touched. You could easily walk under the trunk, if you dared (and we did), and you probably could drive under it, but of course the motion of the car just might be enough to make it crack in half and crush some unlucky car and its driver. Or maybe it might make the phone line shake a bit …

No thanks.

So, we didn’t drive under.

I called the emergency phone for the cell phone tower (whose access road we share) to alert them that the road was blocked and could only be cleared by a professional. I also attempted to call a phone company via 611, without much success — after a long wait, the person at the other end eventually asked me for the code to my account before they would forward me to somebody who could take care of it. Very weird and confusing. What account? What code? My bank account? No way. We will both call tomorrow. Paul says he knows some lawyers at Verizon, whose line he thinks it is.

But then: how were we going to turn the cars around? It’s a very narrow road, with rocks and trees on one side. The other side has sort of a ravine and yet more trees. Paul realized before I did that we had to help each other and give directions in the darkness to the other person, or else we would have to back up all the way to the gate! Turning around took about four maneuvers, per car, in the dark, with the other person (armed with astronomer’s headlamp, of course) yelling directions on when to turn, how much to go forward, when to stop backing up, and so on. Success – no injuries! We both got our cars turned around, closed them up, got our cutting tools, gloves and hats, and then hiked the rest of the way up, south and along the ridge and past the big cell phone tower, to the Observatory buildings themselves, moving and cutting trees as we went.

As we were clearing the roadway and walking up the ridge, we peered to the west to try to find Venus and Mercury, which had heard were now evening planets again. It wasn’t easy, because we were looking through LOTS of trees, in the direction of a beautiful multi-color, clear-sky sunset featuring a bright orange line above the ridge to our west. Winter trees might not have any leaves, but they still make the search for sunset planets rather tough. Even if you hold perfectly still, one instant you see a flash that’s maybe a planet, or maybe an airplane, and then the branches (which are moving in the breeze, naturally) hide it again. So what was it? Paul’s planetarium smartphone app confirmed he saw Venus. If the trees weren’t there, I think we also would have seen Mercury, judging by Geoff Chester’s photo put out on the NOVAC email list. I think I saw one planet.

In any case, everything at the observatory was just fine – no tree damage on anything, thanks to our prior pruning efforts. The Ealing mount and its three main telescopes all worked well, and the sky and stars were gorgeous both to the naked eye and through the scopes. Orion the Hunter, along with the Big Dog and the Rabbit were right in front of us (to the south) and Auriga the Charioteer was right above us. Pleiades (or the Subaru) was off high in the west. Definitely the clearest night I’ve had since my visit to Wyoming for the solar eclipse last August, or to Spruce Knob WV for the Almost Heaven Star Party the month after that.

Paul said that he and his daughter had been learning the proper names of all the stars in the constellation Orion, such as Mintaka, Alnilam, and Alnitak. As with many other star names, all those names are Arabic, a language that I’ve been studying for a while now [but am not good at. So complicated!] Mintaka and Alnitak are essentially the same Arabic word.

After we got the scopes working, Paul suggested checking out Rigel, the bright ‘leg’ of Orion, because it supposedly had a companion star. {Rajul means “leg”} We looked, and after changing the various eyepieces and magnifications, we both agreed that Rigel definitely does have a little buddy.

I had just read in Sky & Telescope that Aristotle (from ancient Greece) may have given the first written account of what we now call an “open cluster” in the constellation Canis Major (Big Dog – that’s Latin, which I studied in grades 7 – 12) called Messier-41, only a couple of degrees south of Sirius, the brightest star in the sky. A passage in a book allegedly written by Aristotle (roughly 230 BC) seems to indicate that he could see this object with averted vision. (He was trying to establish that it was a fuzzy patch in the sky that was most definitely NOT a comet, just like Charles Messier was doing almost exactly two thousand years later!)

M41 was quite attractive. But no, we didn’t then look at M42. Been there, done that many times before. And no, what you see with a telescope does not have all those pretty colors that you see in a photograph.

Instead, we looked on a multi-sheet star atlas (that stays in the observatory) near M41 and found three other open clusters, all really beautiful. We first found M38 and thought that in the C-14 and 6″ Jaegers, it looked very anthropoid or like an angry insect, if you allowed your mind to connect the beautiful dots of light on the black background. In the shorter 5″ refractor made by Jerry Short, it looked like a sprinkling of diamond dust. This cluster must have been formed rather recently. We then found M36, which was much less rich, but still quite pretty. Lastly, we found M37, another open cluster, which has a very bright yellow star near the center, against background of much fainter stars. It seemed to me that those other stars might be partly obscured by a large and somewhat translucent cloud of dust. We saw a web of very opaque dust lanes, which we confirmed by readings on the Web. Really, really beautiful. But I’m glad we don’t live there: too dangerous. Some of the stars are in fact red giants, we read.

Then we looked straight overhead, in the constellation Auriga. We decided to bypass the electronics and have Paul aim the telescope, using the Telrad 1-power finderscope, at one of the fuzzy patches that he saw there. He did, and my notes indicate that we eventually figured out that he found Messier-46 (yet another open cluster) with his naked eye! Very rich cluster, I think, and we even found the fan-shaped planetary nebula inside!

At this point we were getting seriously cold so we moved over just a little, using the instruments, to find M47, again, a very pretty open cluster.

Realizing that the cold and fatigue makes you do really stupid things, and that we were out in the woods with no way to drive up here in case of a problem, we were very careful about making sure we were doing the closing up procedures properly and read the checklist at the door to each other, to make sure we didn’t forget anything.

On the walk back, we saw the Moon coming up all yellowish-orange, with the top of its ‘head’ seemingly cut off. When it got a bit higher, it became more silver-colored and less distorted, but still beautiful.

I really thought all of those open clusters were gorgeous in their own right, and I think it would be an excellent idea to make photographs of them, but perhaps black dots on white paper, and give them to young folks, and ask them to connect the dots, in whatever way they feel like doing. What sorts of interesting drawings would twenty-five students come up with?

I am not sure which of our various telescopes would do the best job at making astro images. I have a CCD camera (SBIG ST-2000XM), with a filter wheel. What about just making it a one-shot monochromatic black and white image? I also have a Canon EOS Revel XSI (aka 450D, I think). Compare and contrast… The CCD is really heavy, the Canon quite light. I also have a telephoto lens for the Canon, which means that I have essentially four telescopes to choose from (but not a big budget!). One problem with the C-14 and my cameras is that the field of view is tiny: you can only take images of very small bits of what you can see in the eyepiece with your naked eye. This means you would need to make a mosaic of numerous pictures.

In any case, no imaging last night! Not only did I not feel like hauling all that equipment for a quarter of a mile, after all that chopping, sawing, and shoving trees, it turns out I had left my laptop home in the first place. D’oh!

I had previously found every single one of these open clusters when I made my way through the entire Messier list of over 100 objects, with my various home-made telescopes, which had apertures up to 12.5 inches. However, I don’t think I had ever seen them look so beautiful before! Was it the amazing clarity of the night, or the adventure, or the company? I don’t know!

But this was a very fun adventure, and this photography project – attempting to make decent images of these six open clusters – promises to be quite interesting!

 

 

 

 

 

Australian TV Bit on Me and the DC ATM Workshop

27 Monday Nov 2017

Posted by gfbrandenburg in astronomy, astrophysics, nature, Safety, science, Telescope Making

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2017, ATM, Australia, eclipse, Stephanie March, Telescope

Some very nice folks from the Australian Broadcasting Corporation came and interviewed me on film for a bit on folks who make their own telescopes to see the great August 2017 eclipse. Here is the link:

( https://www.facebook.com/abcnews.au/videos/10157157152414988/ )

An Eclipse Seen in Wyoming

27 Sunday Aug 2017

Posted by gfbrandenburg in astronomy, astrophysics, Math, nature, Telescope Making

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eclipse, Lander, luggage, Math, solar, sunspots, totality, travel, Wind River Indian Reservation, Wyoming

I was fortunate enough to have the time and cash to go to Wyoming for the August 21 eclipse. It was truly wonderful,. in large part due to the fact that I had made a 6″ diameter, f/8 Dob-Newt travel telescope that could play three roles: as an unfiltered projection scope onto a manila folder before and after totality; with a stopped-down Baader solar filter during and after totality; and with no filter at all during the two minutes or so of totality.

No photographic image that I have so far seen comes anywhere near the incredible details that I was able to see during those short two minutes.

Here is my not-very-expert drawing of what I recall seeing:

solar eclipse

The red rim on the upper left is the ‘flash spectrum’, or chromosphere. It was only visible for a few seconds at the very beginning of the eclipse. The corona is the white fuzzy lines, but my drawing doesn’t do them justice. On the bottom, and on the right, are some amazing solar prominences — something that I don’t recall having seen in 1994, my first successful solar eclipse. The bottom one might not have been quite that large, but it really got my attention.

Here are a few photos I took before and after totality:

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IMG_8105
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IMG_8120
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I started planning this expedition over a year ago, and hoped to attend the Astronomical League meeting in Casper, WY. I quickly found that there were absolutely no rooms to be had there, even a year in advance.

Wyoming has fewer people than my home town (Washington DC), and not many populated places in the path of totality. However, I did find a motel in tiny Lander, Wyoming, very close to the southern edge — a location that I had previously found to be very good for viewing eclipses. One of the fellows in our telescope-making workshop, Oscar O (an actual PhD solar astrophysicist) decided he would bring some family and friends along and camp there to view it with me. So he did (see the group photo).

The night before, we went to a site near Fossil Hill, WY to look at stars. The Milky Way was amazing, stretching from northern to southern horizon, and the sky was very, very dark. We met a baking-soda miner (actually, a trona miner) and his 10-year-old daughter; she had a great time aiming my telescope, via Telrad, at interesting formations in the Milky Way. My friends from DC whipped up an amazing dinner on their tiny camp stove. There were LOTS of people camping in the back country there; I bet most of them were there to view the eclipse!

On the eve and morning of the eclipse, after consulting various weather ‘products’, we decided that the predicted clouds in Lander itself would be a problem. (I had been clouded out before, with my wife and children, back in 1991, in Mexico! It really spoils the experience, I assure you!)

So we drove north and west, through the Wind River Indian Reservation, and picked a spot just east of the tiny town of Dubois at a pulloff for a local fish hatchery. Along the drive to that location, we saw lots of folks had set up camp for the event at various pulloffs and driveways to nowhere. (If you didn’t know, Wyoming is mostly devoid of people, but has lots of fields and barbed wire fence. Many of those fields have driveways leading to some sort of gate, most of which are probably used at least three times every decade, if you get my drift….)

Not only is Wyoming largely empty (of people), but the path of totality in the United States was so long that I estimated that if the ENTIRE population of the USA were to decide to go view the eclipse, and somehow could magically spread themselves out evenly over the 70-mile-wide, and 3000-mile-long, path on dry land, that there would only be about 3 people per acre!

Here’s the math: 70 miles times 3000 miles is 210,000 square miles. The population of the USA is about 330,000,000. Divide the population by the area, and you get about 1600 people per square mile. But there are 640 acres in a square mile, so if you divide 1600 by 640, you get less than 3 people per acre, or 3 people on a football field (either NFL or FIFA; it doesn’t matter which).

(…looking to the future, the next decent eclipse doesn’t seem to occur anywhere in this hemisphere until 2024, when it will cross from Texas to Maine…)

As you can see from my photos, the little travel scope I made, called Guy’s Penny Tube-O III, performed very well. Before and after totality, we used it both for solar projection onto a manila folder, through the eyepiece. I also had fashioned a stopped-down solar filter with a different piece of cardboard and a small piece of Baader Solar Film. With both methods, we could clearly see a whole slew of sunspots, in great detail (umbra and penumbra) as well as the moon slowly slipping across the disk of the sun. Having the sunspots as ‘landmarks’ helped us to watch the progress!

Then, during totality, after the end of Baily’s Beads and the Diamond Ring, I took off the filter and re-adjusted the focus slightly, and was treated to the most amazing sight – a total eclipse, with coronal streamers to the left and right; the ‘flash spectrum’ appearing and winking out on the upper left-hand quadrant (iirc); and numerous solar flares/prominences.

I got generous and allowed a few other people to look, but only for a few seconds each! Time was precious, and I had spent so much work (and airfare) building, and re-building, and transporting that telescope there!

Planets? I didn’t see any, but others did. Apparently Regulus was right next to the Sun, but I wasn’t paying attention.

The corona and solar flares were much, much more pronounced than I recall from 1994.

That afternoon, the town of Lander had the largest traffic jam they had ever had, according to locals I talked to. Driving out of there on that afternoon was apparently kind of a nightmare: the state had received a million or so visitors, roughly double its normal population, and there just aren’t that many roads. I chose to spend the night in Lander and visited from friends I had gotten to know, who are now living in Boulder, on the night after that. Unfortunately, on that next day, I got a speeding ticket and a citation for reckless driving (I was guilty as hell!) for being too risky and going too fast on route 287, trying to pass a bunch of cars that I thought were going too slow…

When I did fly out from Denver, on Wednesday, all the various inspections of my very-suspicious-looking and very-heavy luggage caused me to miss my flight, so I went on standby. It wasn’t too bad, and I was only a few hours later than I had originally planned. And my lost suitcase was delivered to my door the next day, so that was good.

I am now in the process of making this travel scope lighter. I have removed the roller-skate wheels and replaced them with small posts, saving several pounds. I have begun using a mill to remove a lot of the metal from the struts. And I will also fabricate some sacks that I can fill with local rocks, instead of using the heavy and carefully machined counterweights! (Rocks are free, gut going over 50 pounds in your luggage can be VERY expensive!)

 

By the way: unless you like to travel with no luggage at all, NEVER use Spirit Airlines! They may be a few dollars cheaper, but they will even charge you for a carry-on bag! What’s next? Charging you for oxygen?

 

 

Actual images of various rovers on Mars — as well as aftermaths of unfortunate crashes

23 Friday Jun 2017

Posted by gfbrandenburg in astronomy, astrophysics, History, monochromatic, science

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Tags

Mars, Moon, rovers

Proof once again that yes, NASA and the ESA and the Russians have indeed sent rovers and spacecraft to Mars (as well as to the Moon) – photos taken by various orbiting satellites.

Telescope Fix, Scudding Clouds Over Moon, Tom Turkeys Hiding, and Successful Cloud Chamber!

12 Monday Dec 2016

Posted by gfbrandenburg in astronomy, astrophysics, science, Telescope Making, Uncategorized

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Tags

cloud chamber, Digital Setting Circles, dry ice, Isopropanol, Moon, Sky Wizard, Turkeys

I had a productive 24 hours!

  • Night before last, I think I finally got Sky Wizard Digital Setting Circles installed on the 14″ alt-az telescope we were most generously donated by Alan Bromborsky. (That’s me, in the operations cabin  at Hopewell Observatory, taking a break and a picture, long before completion.)img_6169
  • So I went out to look at the sky at 1 AM. I saw no stars, but the 80% gibbous moon appeared to race dramatically through the clouds
  •  That afternoon, as I was driving out, I saw 5, maybe 6 tom turkeys playing hide-and-seek with me behind the trees. Believe me, they are REALLY GOOD at hiding behind little saplings, logs, and rocks! Or if you don’t believe me, ask anyone who’s tried to hunt them.
  •  Late that evening, I got a dry-ice-and-isopropanol particle detector working for the first time. (I had tried and failed, when I was a teenager, some 50 years ago, and failed several other times since then as well.) If you look at my little video, you can see the particles more easily than I could with your naked eye as I was filming it. Don’t ask me yet which ones are muons, which are alpha particles, and which are beta particles, because I don’t know yet. But you could look it up!

Productive 24 hours!

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