Archive for September 2022

The 8-Inch “Orange Tube” Schmidt-Cassegrain f/10 Telescope, Founder Tom Johnson, And Other

September 26, 2022

I pulled the following photo of (Leonard Nimoy) “Spock” and his “Orange-Tube” 8-inch Celestron Schmidt-Cassegrain telescope, from Phil Harrington’s vintage telescope advertisement post.

This is the telescope, that changed the world of amateur astronomy, with its introduction in 1970. 

Amateurs wanted a more compact and portable telescope, and the 8-inch Schmidt-Cassegrain f/10 fit the bill.  I’ve owned two SC scopes over the years, but as for me, this design is not my favorite.  

However, the Schmidt-Cassegrain telescope is the choice of telescope for many amateurs, for their own personal reasons. I’d suggest mostly for portability, and astrophotography.

Newtonian Reflectors:

It’s my opinion, a 10-inch “equatorially mounted” (solid tube) reflector, is the largest reflector that can/could be considered portable.  And that’s a stretch, as I have a very heavy 10-inch EQ reflector (solid tube) so this is based on my experience.  

However, this is not the case for a Dobsonian design, as many take 20 to 25-inch Newtonian’s, and sometimes “even” larger to star parties on a regular basis.  

My experience with a 20-inch Dobsonian: 

I’ll never forget being at a star party near Blowing Rock/Boone, North Carolina, and climbing a “really” tall ladder, to observe through a 20-inch Dobsonian.  To make things worse there was a 15 mph wind, and “of course” in total darkness.  I couldn’t wait to get back on ground, and decided my 10-inch reflector was all I needed!  I just never thought astronomy should be a hazardous hobby, even greater than road cycling!

I’ve always preferred the simplicity of both a Newtonian and refractors:  

For me, growing up looking at big Cave Newtonian’s (advertisements) and other brands, with massive German design equatorial mounts, was what an astronomical telescope should look like.

We can never escape our early years, and thoughts.

Roger Ivester 

The following is an excerpt from Wikipedia, concerning Tom Johnson and Celestron telescopes. 

…..Johnson, who had a strong interest in amateur astronomy, originally created Celestron as the “Astro-Optical” division of Valor Electronics in 1960.[2][3] Around 1960, Johnson had been looking for a telescope which could be used by his two sons, but found no such child-friendly models on the market at the time.[2] Johnson built a new telescope, a 6-inch reflector telescope, by himself, in 1960.[2] He was visiting his brother in Costa Mesa, California when he came upon his nephew, Roger, trying to grind the 6 inch diameter lens he purchased from the clearance table at a local hobby shop. Roger was tired of the project and offered the lens-grinding kit to his uncle. Thomas Jasper took the kit home and after several days of hand grinding, he invented a machine that would grind the lens for him. Thus, by accepting the lens grinding kit from his nephew, Roger L. Johnson, “TJ” (as the family called him) created that first lens of many.

On July 28, 1962, he publicly unveiled a new invention, a portable 18+34-inch Cassegrain telescope, at the party held by the Los Angeles Astronomical Society on Mount Pinos.[3] The new transportable telescope proved so groundbreaking that Johnson’s invention was featured on the cover of a 1963 issue of Sky & Telescope.[3]

Johnson’s interest in telescopes soon became a full-fledged business.[2] Johnson’s new company, Celestron, which descended from the “Astro-Optical” division of Valor Electronics, soon began selling more sophisticated Schmidt–Cassegrain telescopes in models ranging from just 4 inches to 22 inches.[2] However, the Schmidt–Cassegrain telescope proved difficult to mass-produce because the models needed Schmidt corrector plate, an advanced aspheric lens, which could be hard to manufacture.[2] To solve this production problem, Johnson and the company’s engineers invented a new type of telescope, the Celestron 8, in 1970.[2] The Celestron 8 was more compact, affordable and easier to manufacture than traditional telescopes, like the Schmidt–Cassegrain.[2] Johnson’s new telescope proved very popular in the amateur astronomy and educational industries, allowing the hobby to rapidly expand and reach more consumers.[2]

Johnson sold Celestron in 1980.[2]

NGC 6751 Planetary Nebula In Aquila: September 2022 Observer’s Challenge Object: #164

September 23, 2022

Fall: September 22nd, 2022 And Watching The Shadow As The Sun Begins Its Crossing Of The Celestial Equator, Heading South. The Cooling Of The Northern Hemisphere Will Soon Follow.

September 22, 2022

During the Vernal Equinox (March 20th 2022) my grandson, John-Winston and I constructed solar devices (from different locations) to watch the shadow of the sun with the changing of seasons.

It’s fun having a joint project with my oldest grandson, talking about the sun shadows, and watching the changes from week to week, and month to month.

See the following photos:

The yellow mark at the (9) was the suns shadow on the March 20th Vernal Equinox. Our first measurement.

The white mark on the (2) was placed on the first day of summer (June 21st)

The red mark was placed today, September 22nd at 1:00 PM EDT, or 12:00 Noon EDT. All marks were made at 1:00 PM EDT.

Note: The 12-inches of a metal tape measure is used for a reference only…when discussing, or communicating.

For contemplation:

If you are an amateur astronomer in any sense, which you are, or you’d not likely be reading this post, consider doing the same with a young person. And you will never know what will result from the seed “you might have planted” in the future.

You will “for sure” get more out of this project, than the student.

The shadow today as following:

While Observing Last Night, A Strange Thing Happened. Two Kids Walked Up In Their Halloween Costumes: Find Out What Happened.

September 21, 2022

Last night (September 20th, 2022) I was planning a brief observing session, primarily to view the faint open cluster, NGC 6791 in Lyra. It’s been almost ten years since observing this cluster the last time. However, just after getting my telescope ready, a couple of kids walked up “seemingly” dressed in their Halloween costumes. I thought it was a bit too early for Halloweenbut you know kids.

It was dark, so I really couldn’t see them, but invited them up on my deck. They didn’t say a word. I asked if they’d like to look through my telescope and both nodded their heads. One seemed to be very familiar with telescopes, and actually picked up a clip board and started sketching the Andromeda galaxy. The one wearing a white sheet…just looked on.

I went inside to get Debbie to come outside, to meet the pair, but when we returned, both were gone. How did they “get gone” so fast? Strange indeed….

I’m glad I took a photo of the kids, as otherwise, I might have thought I was hallucinating…possibly due to a very hard and hilly bicycle ride in 90º heat, only a few hours earlier.

Unfortunately, I was unable to observe open cluster NGC 6791, as the sky had become completely cloudy. And also, one of the kids took my small clipboard, extra 5 x 8 sketch pads, and also two pencils. You can see one of the pencils being held in the big ones mouth.

A strange night for sure, but one I’ll always remember.

I’ve always adhered to the following quote:

So, whoever shows up and wants to look through your telescope, even if they are dressed in a Halloween costume, a bit too early…let them!

A Simple, Cheap And Easy Way For The Suburban Back Yard Amateur To Observe, Despite That Neighbor’s Pesky Porch Light Or A Terrible Street Light. Interested?

September 15, 2022

I’ve been a humble visual observer for more than forty years, and have never owned or had a permanent observatory.

Why? My back yard has never been worthy of the investment, so I have to observe from different locations in the yard, based on the location of the deep-sky object.

Example: Any object with a south latitude, requires that load up my telescope and supporting equipment and drive to a dark site. However, in recent years I do this very seldom. I just don’t like all of the effort required, loading and driving to a remote dark-site, all by myself and beyond cell phone range.

So, for those more southern objects, I take my telescope and equipment out into the back yard, but often have a neighbor that will leave their back porch light on. And, also there is a distant street light that shines into the corner of my eye. Such an annoyance…

Last month, I had problems locating and seeing the Observer’s Challenge object, which was planetary nebula, NGC 6772…but finally was successful, but without a good view due to ambient light.

It took me extra time to observe, sketch and make notes of NGC 6772, so I was not able to observe, the September challenge object, planetary nebula, NGC 6751, also in Aquila.

However, for all deep-sky objects greater than -02º S latitude, I can observe from my back deck, using my GoTo mount, which is great, and without having a problem with lights.

I just don’t know why, I’ve let this mount, a Celestron CGE-Pro Mount sit in the corner of my living room for at least eight years. I have panels and light blocks built on my deck, so lights are not a problem. And it’s so easy to move the mount only 10 feet, and bolt down via inserts in the deck.

I’ve increased the number of support posts under the deck, to insure there are no vibrations while observing. I have a custom stainless steel base for the Pro mount with wheels and large levelers, but at a weight of almost 200 pounds. This base in now in storage, as it’s no longer needed.

My new location for storing the above equatorial mount: A Rubbermaid plastic storage building, located on my back deck, and only feet away from the deck inserts.

Back to my back yard, and my “easy” to make, and set-up…light block panel.

I was not going to deal with that “pesky” street light which “almost” ruined my observations of NGC 6772, so I did the following, and taking less than 30 minutes to construct. And today, I’ll take it down…maybe taking less than 10 minutes.

Materials required:

Two 8-foot metal fence poles, from Lowe’s Home Improvement Center.

25 feet of HD nylon, and two plastic tent pegs, also from Lowe’s…also a few wooden clothes pins.

At one time I was associated with a company that manufactured marine fabrics. A Very heavy black woven cloth, with a backing. No light can shine through this fabric!

So, last night I was successful in “easily” locating, and seeing the planetary nebula NGC 6751 , also making a decent sketch and notes, which “again” is the September Observer’s Challenge object.

So easy!

This is the medium duty mount, I use when observing with my 10-inch reflector, from the back yard. It’s heavy, but not that heavy.

So, if you are a suburban observer, and have trouble with “pesky” lights…give the portable light block a try. Roger Ivester

Organizing My Pencil Sketches And Notes, However, It’s Taking Much More Time Than I Thought.

September 14, 2022

Several months ago, it occurred to me that I needed a more organized system of filing my pencil sketches and notes. I was just filing my 5 x 8 sketches in plastic boxes, without having a directory, and having to look through hundreds of sketches to find the one I might be looking for. I have spent about sixteen hours to-date, and with many more hours to go.

I am using a laminator, lamination plastic, a paper cutter, plastic page protectors, and plenty of 3-inch loose leaf notebooks. When finished, there will be a directory in front of each notebook, then a master list to find the notebook needed, and then the page number.

This is a preliminary post, and I will be adding more information when the task is finished. At this point, I have five complete notebooks. I have all of my sketches digitized for the past fifteen years, but nothing like a “hard-copy.”

Four books now completed, with the fifth, just beginning. There is no way, I can laminate all of my sketches, and notes, as they are in different formats, journals, and too many small 3 x 5 cards to count.

Maybe a thousand or more small note cards ( 3 x 5) filed in plastic boxes, by constellation. So they are just fine, and easy to locate…the object I might be looking for.

The following are the books to-date with Debbie’s hand holding.

NGC 253 – Galaxy In Sculptor: It’s Far South -25º South Declination Deters Many Amateurs From Observing. However, It’s Possible To Be Observed From Anywhere in The Continental US.

September 9, 2022

Richard Nugent and Bruce Berger saw the galaxy from Maine at +45º N latitude.

Pencil Sketch as following by Bertrand Laville from France, using a 25-inch Reflector:

Image by Mario Motta:

The data was collected in 2019, counting the number of subs, I have 70 min both Blue, and red filters, and 60 minutes Lum Filter. Green filter was only 40 minutes, likely it began to set in the west too low and could not get more.

This was taken with my 32-inch scope from Gloucester MA, with a ZWO ASI6200 camera.

Processed in Pixinsight

Image by James Dire:

Date/LocationNovember 15, 2009 Wildwood Pines Observatory, Earl, NC
Camera and SettingsSBIG ST-2000XCM CCD Camera -10°C
TelescopeOrion 190mm Maksutov-Newtonian f/5.3
MountParallax HD150
Exposure60 minutes (6 x 10 min)
ProcessingCCDOpts, Image Plus 3.0, Photoshop
OtherMag. 7.1 spiral galaxy in Sculptor. 26.9 x 4.6 arc minutes.

Pencil Sketch by Roger Ivester from North Carolina:

14.5-inch reflector at 125x, from a local dark-site in North Carolina at +35º N latitude on October 22nd 1995. I made the following sketch using a white charcoal pencil on black card stock.

South is up, and East is to the right.

Pencil Sketch by Sue French from New York at +43º N latitude:

10-inch reflector at 68x

Equatorial Mounts With Stiction, and How to Fix. What is Stiction?

September 2, 2022

Stiction: Physics = “The friction which tends to prevent stationary surfaces from being set in motion”

I have an older Meade “medium duty” equatorial mount.  Last night (August 31, 2022) was beautiful with low humidity, and temps in the lower 60’s.  It’s been a while since I’d used this mount, and when locating planetary Nebula NGC 6772, but last night, the RA and Declination shafts were “jerky” or sticking, called “stiction.”  

This mount has teflon/nylon split bearings, and over the past 30 years, knowing that a petroleum based lubricant can attack plastics, nylon and teflon. I have always disassembled and used paraffin.

It occurred to me to use some Mobil 1 synthetic motor oil in a tiny plastic dropper. 

So, today…with another great night coming up, I had to correct the problem, without disassembly.  I removed the counter weights, and flipped the RA and Dec shafts in all angles, and dripped small drops of Mobil 1 synthetic motor oil into areas that would allow permeation of the internal surfaces. 

I learned about Mobil 1 for lubricating bushings, spacers and other, by cleaning and reassembly of Zipp Carbon Fiber Road Bike Wheels. Zipp advocated the purchase of their “special” Zipp Wheel lubricate for internal spacers, and warned not to us a Petroleum based.  But, somehow, I found out that the Zipp Special Lubricate “might be similar” to synthetic motor oil, like Mobil 1.  

I’ve cleaned and disassembled many Zipp wheels, for myself and others for more than 10-12 years, and lubricated the internal parts of the freehub assembly with Mobil 1, and all are doing fine.  The carbon fiber wheels are hand-built, with each “individual” wheel requiring many hours (maybe 25 or more hours per wheel) to manufacture.

How did the lubrication work?

The Meade Medium Duty mount seems to now work beautifully, but with the waxing moon, I’ll have to wait till the 2nd or 3rd quarter moon to attempt NGC 6751 again.

Hopefully this post might be of benefit to others with “sticky” equatorial mounts.

I have also found out others are using Mobil 1 in astronomical applications also.

Information from Mario Motta, as following:

Hello Roger,

Once a year I carefully clean off old grease from my 32-inch drive gear, and add back Mobil 1, which gives me a much smoother tracking.

Mario Motta

The declination gear is aluminum alloy made by a machinist in Alaska in 2004. It is 16.6-inches in diameter with 360 teeth.

The RA gear is a beauty, made by Byers. (There is a long story behind this gear). It is 23-inches in diameter, and has 718 teeth. 

It is extremely accurate as all Byers gears are. I was originally using my Byers gear from my previous observatory, 15.5-inches, but just a bit too small for a 32-inch telescope. 

Byers got in touch with me just before he closed his shop at age 91, and gave a special offer, which I gladly accepted!  

Mario Motta

Byers advertisement from 1975

The passing of Edward Byers: