Telescope Toy Story

You know the story. Andy’s sixth birthday brings him Buzz Lightyear, displacing Sheriff Woody. The other toys share Woody's grief until (as always) they confront and surmount the challenges. And they lived happily ever after. 

Right now, 14:23 hours 05-July-2026, we are in the trope’s “save the cat” pages of the script. 

[Earlier versions of this narrative were posted to Cloudy Nights discussion “New 70mm Maksutov from Spectrum Optical Instruments” started by Jim Riffle on December 3, 2022 in the Cats & Casses Forum. My comments there are #321, #323, and #335.] 

Back left: white: Explore Scientific 102-mm doublet refractor
Front left Astronomers Without Borders 130-mm Newtonian 
At right: Spectrum Optics Tour Star Pro Maksutov-Cassegrain.

The Newt Rebellion

June 27: For the past couple of weeks, I have been getting out more with my “tabletop Dobsonian” from Astronomers Without Borders. It is a Newtonian reflector 5 inches (130 mm) in diameter and it comes without a tripod but it does have a Vixen mount for universal compatibility and I put it on a ES First Light Pan-Tilt Mount.

The AWB dob needed collimation (aligning the primary and secondary mirrors) but it was not too far off and it pretty much stayed that way night after night. The time before last, I tweaked it again and made it dead-on to within a gnat's whisker. The next afternoon (June 28), the Spectrum Optics Maksutov Cassegrain telescope arrived from Astronomics and I set it up. 

Left: AWB 130 on ES First Light Mount.
Right: Meade StarPro 70 mm.
They got along fine.  

Set-up was easy. I intended to take out the AWB reflector to compare the views. When I looked in the collimation eyepiece, the view was horrific: the entire primary mirror was two-thirds off center, ten times more wrong than it ever had been. I adjusted the three primary screws at the back. That was ineffective. I adjusted the three secondary hex bolts up front. The changes were not the ones I sought. I loosened the main mount of the secondary mirror mount. It only got worse. I took the AWB 5-inch reflector and two cases of small tools into the house. 

Unexplained Sightings 

June 29. After the unusual failure of the 130-mm Newtonian from Astronomers Without Borders, I took out the Explore Scientific 102-mm doublet refractor. To other stargazers, I identify this as “my grab-and-go.” On its mount, with accessories, the package is 20 lbs (9 kg) and it always works. Tonight, the red-dot LED finder scope would not come on. 

Click. Click-click...pause...wait... do it again... 

Easy enough, I got another battery. Nothing. Click. Click-click...pause...wait... do it again… Batteries fresh from the pack seldom fail, therefore the LED on the finder must be dead. (Later, I checked the battery and it still had high potential at 3 volts.)

Next, I chose a Celestron 51630 Star Pointer from inventory. With dabs of white-out, I match-marked the On-Off and Up-Down and went out and ran errands. A couple of hours later, I went to the telescope to check the alignment on the red dot finder and the On-Off switch was broken: it clicked Off but rotated fully through On without clicking On. and there was no red dot.

Explore Scientific 102-mm refractor.
Note at right on the eyepiece mount 
is a Stellarvue Correcting Prism with fine focus.
(I think that taking this off the ES-102 and putting it
on the Mak-70 was a point of contention among the scopes.)

Portland Cement on a Horta

July 3. I filled out a request slip and gave my tool check to the guy at the crib for an AstroTech Multiple Reticle finder the same as I use on my AstroTech 115 mm  Extremely-low Dispersion Triplet refractor. Then I found a new base to fit both the ES 102 telescope and the new finder. I settled on the closest match and superglued the plastic bases to each other. 

Homepage ad from Spectrum Optics
At $159 it was very competitive in its class.
Astronomics had these for $100. 
So, I bought five for four friends and myself. 

Right now, the mount for the finder is narrower than the draw of the clamp attaching it to the stand. So, now, I am looking for shims. Passing up scrap aluminum and plastic, I tried folding and rolling paper, then turned to plastic soda straws before cutting to lengths a cardboard stylus for cellphones. To hold the shims, I used SuperGlue gel. It is not a permanent repair but it will work until I get new finders from Explore Scientific. Now, I can use the grab-n-go for all of the deep space objects in my southern skies from 10:00 PM to 2:00 AM and continue to test the Maksutov against the near competitors in my shed.

[Sunday. July 11. 23:30. Like the Official Dog in Eric Frank Russell's "Alamagoosa," the patch failed under gravititic stress. The telescope is back in the shed under wraps "until I get new finders from Explore Scientific."]

[Tuesday. July 14. 16:03. I bought three replacements from Explore Scientific. (I have another 102-mm refractor like this one but longer.) The trees that they are on do not fit the slot in the telescope. I got out the shoebox with new and used finder bases and found a close match. After sighting and aligning on a nearby chimney, when I go out again, I will have to remember that "center" is down and to the left of the red dot.]

 

The salient problem remains: Why all the failures? 

Notes: 

Astronomers Without Borders branded their entry-level hobbyist instrument in the name of John Dobson, a problematic Vedanta Hinduist who sought to unify religion and science by building large telescopes from scrap parts and taking them to the streets of San Francisco to show people the skies they did not know.  

A Sidewalk Astronomer, documentary film by Jeff Jacobs: 

https://www.youtube.com/watch?v= bVbX19kabNc

Tribute by the Planetary Society

https://www.planetary.org/profiles/john-dobson

Wikipedia of course

https://en.wikipedia.org/wiki/John_Dobson_(amateur_astronomer)

Dmitry Dmitrievich Maksutov was serving in the USSR military when he invented this design. Like the Cassegrain and Schmidt, the Maksutov design benefits from a folded optical path, allowing twice the focal length or half the tube size. Moreover, the "negative miniscus" of the secondary optics corrects for spherical aberration. However, the Maksutov design allows aberrations when the diameters of the component mirrors exceed 100 mm (4 inches). So, these tend to be small and lightweight, which is perfect for hobbyists. Moreover, the telescope is sealed: there is nothing for you to adjust. 

PREVIOUSLY ON NECESSARY FACTS

A Good 70-mm Refractor 

National Geographic 70-mm Refractor Field Test 

A Good Entry-Level Telescope 

New Telescope Familiar Sights 

Targets in Scorpius (also Messier 22)

I got out for the first time since March 25. Nominally clear-ish, everything was faint with city lights and water in the air. Aside from Scorpius, Sagittarius, and the Big Dipper, I counted about 80 stars.

[Posted to The Sky Searchers astronomy discussion board.]

Telescope: Explore Scientific 102 mm doublet refractor on Twilight-I Alt-Az manual mount. Eyepieces: Meade 5000 82-degree 14mm and TeleVue 7mm Series 1. 

2234 - Zuben el Genubi

2339 NGC 6231

0006 Lesath and Shaula

0009 Messier 7 Ptolemy's Cluster

0017 Messier 80 - 47X

0022 Messier 80 - 94X 

0026 Messier 4 - no joy. 

0032 Messier 22 in Sagittarius

0039 Messier 6 Butterfly Cluster

The tube was wet. So, I packed everything up and put it all on the porch in case I can go out again later this morning before sunrise.

Thanks and Clear Skies,

Mike M.

Commentary: 

Zuben el Genubi. Claw of the South. Also now designated Alpha Librae because of the Roman compulsion for Twelves which added Libra to their zodiac and made the Scorpion fold up his claws. In a small telescope, this is an easy double star: two Main Sequence F stars about 76 light years from Earth. For myself, I learned of it at a show at the Hayden Planetarium in the summer of 1969. The other claw is Zuben al Schamali and I never get tired of saying their names.

NGC 6231.  An open cluster of about 100 stars mostly traveling together, though of the easily spotted bright pair one is only 15 ly from Earth and not in the group. 

"The original New General Catalogue was compiled during the 1880s by John Louis Emil Dreyer using observations from William Herschel and his son John, among others. ...  https://en.wikipedia.org/wiki/New_General_Catalogue#Index_Catalogue

"This cluster is estimated to be about 2–7 million years old,^[2][3] and is approaching the Solar System at 22 km/s. The cluster and association lie in the neighboring Sagittarius Arm of the Milky Way. Zeta¹ Scorpii (spectral type O8 and magnitude 4.71.^[7]) is the brightest star in the association, and one of the most radiant stars known in the galaxy.^[8] NGC 6231 was used to measure the binary fraction of B-type stars: 52%±8%, indicating that B-type stars are commonly found in binary systems, but not as commonly as in O-type stars.^[3]

NGC 6231 also includes three Wolf-Rayet stars: HD 151932, HD 152270,[9] and HD 152408.[10]". Wolf-Rayet stars are considered unstable and likely to go nova at any time.
-- https://en.wikipedia.org/wiki/NGC_6231.

Lesath and Shaula are the two stars in the Sting. 

Messier 7. Noted by Claudius Ptolemy in the 1st century of our era, it is visible to the naked eye, even in the city under forgiving skies, though not so tonight. It is to the left (East) of Lesath and Shaula. It is an open cluster of about 80 stars, with 20 to 30 easy to tally.

Messier 80 - A globular cluster of several hundred thousand stars packed into a sphere 95 light years in diameter. It is 32,000 light years from Earth. Globular clusters like this orbit the plane of the Milky Way. Current theory is that the disk (as with all "Grand Design" disk galaxies) condensed out of the halo of globular clusters. The Milky Way has about 125 of them now, likely many more earlier, and other galaxies have significantly more globular clusters. In a small telescope, it looks like a roundish patch of lighter gray. It is in the more or less open area between the eastern claw star "Graffias" (gripper) beta Scorpii and Antares in the center of the body. It is fairly easy to find, even on a bad night.

Messier 4 -- No joy. Technically brighter than Messier 80, it is much larger so its light is spread out and it is not always easy to find. I was told, "Messier 4 does not respond well to light pollution." 

Messier 22 -- Big, bright and easy to find in a small telescope, it looks like a dandelion gone to seed. You cannot miss it. It is above the "knob" in the "top" of the "Teapot" which everyone else calls Sagittarius. Just over 10,000 light years away it is one of the "closer" globular clusters. It contains at least 72,000 stars and likely twice that many, as well as several to many black holes swallowing stars. For myself, M22 is the Bay Shore Highway around Traverse City, Michigan. Tourist shops sell M22 decals. We have ours. I also have an M22 coffee cup. 

Messier 6 - The Butterfly Cluster. Maybe more than 30 of the 120 stars are easy to see at 47X with a 4-inch telescope in the city. Likely 1590 light years from us, it is about 12 ly in diameter. It is only 94 million years old and so it has highly metallic stars with abundant elements more complex than helium. 

PREVIOUSLY ON NECESSARY FACTS

Solar Imaging 

Amateur Astronomy for Pay 

Measuring Your Universe: Alan Hirschfeld's Astronomy Activity Manual 

The Perfect Machine 

Setting Up and Using Three Small Telescopes

21-March-2026 General Observing - 14:00 - With a weather forecast of clear and warm (70F) tonight, I took out my usual telescope, an Explore Scientific 102mm doublet refractor. I also unpacked my 5-inch Celestron tabletop Dobsonian reflector from Astronomers Without Borders. I even took out the Sears 6307B/4 60-mm refractor that Laurel found on the street in 2023. My goal was to use this one with my iPhone 15 on a NexYZ adapter to take pictures, at least of the crescent Moon. 

The extra gear was too much weight for the 1962 hardware. I did get to see the Moon at 35X with the 20mm Huygens and then 46X with the 15 mm Kellner oculars. I had other telescopes set up and waiting for use, so I stopped fussing with the camera. With clear nights ahead and no work in the morning, this could be a project. All of us old guys on the astronomy boards started with telescopes like this. (See Mr. Olcott’s Skies: An Old Book and a Youthful Obsession by Thomas Watson, on Cloudy Nights as desertstars.)

I am going to make this joke again: With a 60mm doublet refractor and Huygens eyepieces, I can see what the universe looked like in 1750. 

The AWB Newtonian needed collimation after over a year in storage. The process was the easiest it has ever been. I went in to the archives here under \Astronomy\OtherInstrumentManuals\Collimation and found 63 files. I chose Astro Babys Guide to Collimation. After the introductory materials,  they say on Page 3: 

Rule 1 – Before starting collimation don’t assume that anything is out of kilter and check each element before adjusting anything. About 90% of collimation errors are down solely to the primary mirror so don’t jump in and start meddling with the secondary unless you are sure that there is a problem. Each stage of this guide will show you how to check the various elements – only if they are out

of alignment will you need to make adjustments.[The red is in the original.] 

They continue with a reminder to get all the tools you need before you begin and allow enough time to work this through slowly and do not over-tighten anything. Then on Page 4, they jump right in adjusting things that don’t need attention. “Collimation Step 1 – The Spider Vanes and Secondary Mirror Holder.” So, I put that aside and went to my bookshelf. Philip S. Harrington’s Star Ware: The Amateur Astronomer’s Guide to Choosing, Buying, and Using Telescopes and Accessories.  A quick look at his directions agreed with Astro Baby’s preface. Sighting through the collimating eyepiece and rotating the three adjustment screws and their set-screws, it was easy to put the donut in the center view. 

21:23 - with Meade 5000 14mm 82-degree. Messier 41. 

21:55 Messier 42 - Trapezium sharp. Then, Messier 41, Sigma Orionis, and. Mintaka. 

(There was a lot of playing with the Red Dot Finder on the AWB. I finally got it aligned into agreement with the telescope.)

Put the reflector on a different tripod and put it back in the storage shed with the Sears.

Continued with the ES-102. 

22:29 - Jupiter. wavery; in and out of focus; lots of atmosphere. 

Spent ten minutes lying on the picnic table bench looking up at Leo because it was not distinct at first. The view did not get any better with exposure.

22:32 - a last look at Sigma Orionis; another look around: the Big Dipper was behind the oak tree. I put everything away.

Overall, although I made no personal discoveries it was a good night out following an afternoon of setting up two telescopes that I had not used in over a year. 

PREVIOUSLY ON NECESSARY FACTS

Observation Log (December 28, 2023) 

Virgin Galactic VX01 VX03 

The Structure of Scientific Revolutions 

Tunguska, Chelyabinsk, Berlin, and New York  

Sigma Orionis

We think of Orion as a winter constellation because with shorter days it appears in the early evening sky. It is on the median at 9:00 PM on February 5, but even on April 21, it is just above the western horizon. In September, Orion rises above my eastern tree line by 5:00 AM, and before the Sun erases the night sky at 6:00 AM, it is high in the east. The group associated with Sigma Orionis just below the Belt of Orion consists of stars that are gravitationally bound as well as others that just happen to be there from our point of view.

SIGMA ORI (Sigma Orionis). Double stars are among the amateur's favorite targets, Albireo, Mizar always on the list. Multiples are better yet, and there are few more attractive than Sigma Orionis (which has no proper name), where you see a quartet of stars, the brightest of which is also a close double. Indeed, Sigma Ori, whose five stars together shine in Orion at bright fourth magnitude (3.66) just south of Alnitak in Orion's belt, is really at the pinnacle of a small star cluster that lies a somewhat-uncertain 1150 light years away. In turn, the stars and the cluster are a part of the Orion OB1 association, which includes many of the other stars in the constellation. Sigma's main component, "AB," dominates, the two a mere 0.25 seconds of arc apart shining at magnitudes 4.2 and 5.1. Both very young hydrogen-fusing dwarfs only a few million years old, the brighter is a magnificent blue class O (09.5) star, while the lesser is class B (B0.5). The pair orbit every 170 years at a distance of about 90 Astronomical Units. After correction for ultraviolet light from very hot (32,000 and 29,600 Kelvin) surfaces, they respectively radiate at a rate of 35,000 and 30,000 Suns. Temperature and luminosity give masses of 18 and 13.5 times that of the Sun, the sum of nearly 32 solar masses making the close AB pair among the most massive of visual binaries. Together they illuminate their surroundings, causing interstellar gas to glow. The next brightest stars in the system are Sigma Ori "D" and "E," bright seventh magnitude class B (B2) dwarf stars that at magnitudes 6.62 and 6.65 are nearly identical in brightness and have masses around 7 times that of the Sun. The similarity stops there. "E" is the prototype of the weird "helium-rich" stars that have strangely elevate abundances of helium. Even odder, the helium in "E" seems to be concentrated toward particular patches that involve a combination of the rotational and magnetic field axes. They may be related to cooler magnetic stars such as Cor Caroli, but no one really understands them. The last of Sigma's stars, "C," appears to be a normal ninth magnitude class A dwarf. In projection on the sky, "C" is the closest to the AB pair, and is at least 3900 AU away, while "D" and "E" lie at least 4600 and 15,000 AU distant. While the orbit of the AB pair is stable, the orbits of the other three are not, and long before they die they will probably be gravitationally sped up and forced out. "A" will explode first and may even kick "B" (which will explode next) out of the system. The other stars, wherever they wind up, will die as white dwarfs. The cluster seems also to contain numerous low-mass stars, brown dwarfs, that have masses only a few times that of Jupiter. -- http://stars.astro.illinois.edu/sow/sigmaori.html

 

For early references to the open cluster, see, “On the supposed Variability of the closest Companion of σ Orionis” by W. R. Dawes, in the Monthly Notices of the Royal Astronomical Society for April 1860 (247 1860MNRAS..20..253W 1860/04 and “Correspondence - The Trapezium and σ in Orion” by D. A. Freeman, in the Monthly Notices of the Royal Astronomical Societyfor May 1860 (248  1860MNRAS..20..285D 1860/05). 

 

Drawn with PointPoint from a recorded observation

In 1776, Christian Mayer described σ Ori as a triple star, having seen components AB and E, and suspected another between the two. Component D was confirmed by FGW Struve who also added a fourth (C), published in 1876. In 1892 Sherburne Wesley Burnham reported that σ Ori A was itself a very close double, although a number of later observers failed to confirm it. In the second half of the twentieth century, the orbit o  σ Ori A/B was solved and at the time was one of the most massive binaries known.[22] -- https://en.wikipedia.org/wiki/Sigma_Orionis

 

PREVIOUSLY ON NECESSARY FACTS

Burnham’s Celestial Handbook 

The Andromeda Galaxy 

Asterisms 

What Color is the Orion Nebula?  

Astrophotography Session

 My instrument was an Astro-Tech 115 mm apochromatic triplet (extremely low disperson glass) on a Celestron AVX mount and tripod. The ocular was a Tele Vue 32mm Ploessl 52-degree field of view for 25X. The camera was my iPhone 15 (iOS 18.11) mounted on a Celestron NexYX carrier. I was out from 1:05 to 2:30 AM. I shot 19 stills and movies.

Messier 42: the Orion Nebula

Mintaka: double star with companion

Messier 41 in Canis Major

The Pleiades: Messier 45

PREVIOUSLY ON NECESSARY FACTS

Observing with NASA: an open forum for citizen science

Astrophotography and Me

Astrophotography is a Lot Like Love

Lunar Eclipse 8 November 2022

Jupiter-Saturn Conjunction 2020

Solar Imaging

 We are approaching a sunspot maximum for 2024/2025 and already are above statistically likely events.

 Images with Explore Scientific 102mm achromatic refractor,  TeleVue 32mm Ploessl, iPhone 15 iOS18.11.  Explore Scientifc SunCatcher filter mounted on the objective. These are two of the best six of 13.

PREVIOUSLY ON NECESSARY FACTS

Viewing Mars 

From Texas to the Moon with John Leonard Riddell 

Questions about A Brief History of Time 

Measuring Your Universe: Alan Hirshfeld's Astronomy Activity Manual