November 2nd 2023 At 5:30 AM…

Why an off-axis stop-down mask?

“Often the effects of poor sky stability can be countered to a certain degree. Larger aperture scopes are adversely affected by atmospheric turbulence more than smaller scopes. The cylinder of light of parallel light rays collected by an 8-inch object is subject to a larger cross section of the atmosphere than is that of a 3-inch. The greater the amplitude of of variation in air parcel boundary layers perceived by the system, the more this refractive aberration manifests itself as image wavering. “For certain deep-sky objects (notably double stars) one needs to trade light gathering ability for turbulence reduction. The aperture of the telescope can be reduced by employing a mask over the light gathering end…..” by TL

Tom Lorenzin “1000+ The Amateur Astronomer’s Field Guide to Deep-Sky Observing”

There is science and calculations as to how large the reduction mask should be, and that it should not extend over the light path of the secondary of a Newtonian. However, in past applications, from my experience, going beyond the path of the secondary has never presented a problem. Now there are limits, as common sense would dictate. So, I’d suggest no more than one-inch over the path of the secondary might be a good rule of thumb…if using a 10-inch Newtonian. After all, it’s just a small “crescent” cut-out over the path.

So for my 10-inch Newtonian, this time, I’m using a 5 1/8-inch reduction diameter hole. In the past, my 4.25-inch reduction hole, has worked great for some difficult and very close double stars.

I’ve never tried or attempted to see the companion to Sirius, known as Sirius B with a Newtonian reflector, but anxious to give it a try with my 10-inch f/4.5 Newtonian with an off-axis stop-down mask.

November 2nd 2023:

Beginning at 5:30 AM, with waning gibbous moon, almost 3rd quarter, and still pretty bright. I concluded my session at 7:20, approximately 30 minutes before sunrise. I was able to see the companion, but with difficulty due to poor seeing. I was hoping for a better view of the companion, as it could be seen only intermittently, and Sirius was really ragged and moving.

I kept hoping for that perfect “snapshot” view….one that I can never forget, from that night in March 2016, looking through a friends 100 mm f/8 Takahashi fluorite refractor. Memorable for sure!

Surprisingly, I could still see the companion just as well at 7:20 AM in very “dim daylight” and still with a fairly bright moon, as when I began almost two hours earlier. This would show and prove that double stars can be enjoyed with a moon and light pollution.

The mirror was not cooled down, so I added a fan shortly after beginning, which helped a lot!

If you’ll notice, the companion is near it’s most widest position from Sirius, so if you’ve never seen Sirius B, now is the perfect time, or actually for the next two or more years. So you have plenty of time.

I always keep a small plastic protractor handy, to determine “the Position Angle” for double stars. It’s very versatile, and can work for any type of telescope you’re using. If using a standard Newtonian, just turn the protractor to match your view.

However, if using a Schmidt-Cassegrain, Maksutov or a refractor with a diagonal, which have an uneven number of mirrors….just flip it over and find your actual orientation. A great device for only a couple dollars at Hobby Lobby.

My story of seeing Sirius B in 2012, and then again in 2016, using two separate 102 mm refractors, as following at different locations:

Date: March 14th 2012:

Telescope:  102 mm f/9.8 achromatic refractor, with good seeing and transparency.

I started with a magnification of 83x, but to no avail, and increased to 232x…all the while keeping my eye perfectly still. I used my astro-chair, as it’s very important to be seated for an attempt such as this, or making any deep-sky sketch.  

Knowing the position-angle really helped.  However, I could not hold the companion, or Sirius B constantly.  It was extremely difficult.  But after 40 plus years, I had finally seen the companion to Sirius.  

102 mm Takahashi f/8 fluorite doublet during March 2016

It was actually “very easy” with this scope, and with direct vision. A group of six amateurs took the test using the Takahashi refractor, and what did they see?   

Using the face of a clock, and all without sharing their perceived position of the companion until everyone had the opportunity to observe.  When the last person completed their observation, all correctly identified the position of Sirius B.  

Some were very skilled observers, but a couple or more were not, however, all could “easily” locate and see the companion. 

Roger, thanks so much for the off-axis mask idea….wonderful.

Sirius B:

After several or should say “many” attempts I spotted Sirius B in May 2020, using averted vision. My eyes were tearing, cloth over my head and let Sirius pass through the eyepiece. However, after 45 minutes of struggle, I saw the companion.

To-Date: I have now found and seen the companion, also known as Sirius B several times, but it’s still never an easy. It is important to have a stable and clear sky, and good seeing is “absolutely critical” if you are considering taking on this task.

Interesting; I found if Sirius is in the west and after sunrise, seeing Sirius B is actually easier, which might be surprising to many. Roger Ivester, mentioned the same in his report.

1971 class reunion: October 11th 2025: And a great time was had by all! It was a breezy (windy) and really cool Saturday afternoon.

The 2023 event follows 2025….just keeping scanning down.

I missed getting a “face-on” picture of Debbie. How was that possible? So, I thought I’d just share a photo of Debbie and Sophie from May 2025.

Photos of the 2023 Burns High School class reunion are as following: Much appreciation to Charlotte Sinclaire for taking the lead in organizing this fabulous event. Everything was perfect! A memorable class reunion for sure.

In the following photo…Five guys began 1st grade at Polkville in August 1959, and graduated together at Burns. We were the first class at the new school, and went all four years.

However, after the 5th grade, some of us parted ways for three years, some went to Casar and some went to Piedmont…but back together again at the new Burns High School in the fall of 1967.

Left to right: Charles Melton, Roger Ivester, Rob Pendleton, Bill Ledford and Don Bridges.

Bortle Dark Sky Scale: The Bortle Dark Sky Scale was developed by John Bortle “based on nearly 50 years of observing experience,” to describe the amount of light pollution in a night sky. It was first published in a 2001 Sky & Telescope article.

Depending on the device you are using, it may be necessary to slide the chart to the right to see in its entirety.

Number Code

Map Color Code

Label

Sky Mag.

Naked Eye Limit Mag.

320mm Limit Mag.

M33 visible?

M31 visible?

Central Galaxy visible?

Zodiacal light visible?

Light Pollution

Clouds

Ground Objects

1

excellent dark sky

22.00–21.99

≥ 7.5

> 17

obvious

.

casts shadows

striking

airglow apparent

.

visible only as silhouettes

2

average dark sky

21.99–21.89

7.0–7.49

16.5

easy with direct vision

.

appears highly structured

bright, faint yellow color

airglow faint

dark everywhere

large near objects vague

3

rural sky

21.89–21.69

6.5–6.99

16.0

easy with averted vision

.

complex structure

obvious

LP on horizon

dark overhead

large distant objects vague

4

rural/suburban transition

21.69–20.49

6.0–6.49

15.5

difficult with averted vision

obvious

only large structures

halfway to zenith

low LP

lit in distance

distant large objects distinct

5

suburban

20.49–19.50

5.5–5.99

14.5–15.0

.

easy with direct vision

washed out

faint

encircling LP

brighter than sky

6

bright suburban

19.50–18.94

5.0–5.49

14.0–14.5

.

easy with averted vision

visible only near zenith

.

LP to 35°

fairly bright

small close objects distinct

7

suburban/urban transition

18.94–18.38

4.5–4.99

14.0

.

difficult with averted vision

invisible

.

LP to zenith

brilliantly lit

.

8

city sky

< 18.38

4.0–4.49

13

.

.

.

.

bright to 35°

.

headlines legible

9

inner city sky

.

≤ 4.0

.

.

.

.

bright at zenith

.

.

My view to the east (last night @ 9:15 PM, November 18, 2023 from my back deck) showing the light pollution at about 15º above the treetops.

I always try to observe deep-sky objects at least one hour or two from the meridian.

It is difficult to see the Pleiades “visually” at this low altitude. I was using an iPhone 14 “handheld” to make a photo for illustrative purposes.

The Pleiades was my first deep-sky object when I was 12 years old. I remember so well, walking out in my front yard in about mid-November and seeing this cluster rising above the treetops.

At that time, I had no clue as to what this group of stars were.

A year or so later I found out it was the Pleiades, M45 and my interest in amateur astronomy began, which continues to this day. Interesting to note: This was Leslie Peltier’s first deep-sky object also, as probably so many others.

The following photo:

Andromeda is difficult for me visually, and requires averted vision. At the meridian, it can be fairly easy, but averted vision still works best.

The following photo using my phone, presents the galaxy quite a bit brighter than naked-eye.

So, I estimate the Bortle Scale from my backyard to be ~6.5. I think we can all agree, the Bortle scale is not a definitive number, but using this criteria can describe an observing site pretty accurately. I’d say John Bortle developed an excellent, simple and objective measurement system for judging different observing sites, and for comparison with others.

Meade introduced their Deep-Space telescopes in about the early 1980’s which caught my eye in magazine advertisements.

I was looking for something larger than my 4.5-inch reflector which I was using at that time. The Deep-Space series consisted of two telescopes: A 10-inch and 16-inch f/4.5 telescopes with equatorial mounts.

This was at a time when Meade was building their serious Newtonian’s in their Costa Mesa, facility, which included grinding and polishing mirrors. All of the hardware, bolts and Allen heads on these telescopes and mounts are SAE (Society of Automotive Engineers) and not metric.

Meade, at about this time had just built a state of the art facility in Irvine, California. They were building their Schmidt-Cassegrain telescopes (complete) including the mirrors, coring and the mounts. And at this time they began to make their full line of high-quality refractors with ED glass. This included their German EQ style GoTo mounts, and also the Meade ETX Astro 90mm Maksutov-Newtonian telescopes.

The ETX 90 was a novel idea: To build an incredibly low priced high-performance telescope with all the money and effort going into the optics. The base and arms were made of plastic, but the optical tube was beautiful anodized aluminum.

The ETX 90’s (the ones built in California) indeed had excellent optics. I purchased one shortly after they were introduced, and can attest to the quality of the optics. The later ones that were built in China and Mexico might have been equally as good, but never had the opportunity to test one.

Meade would later send all manufacturing to China and Mexico. Meade, began having quality issues and customer service became nonexistent. However, as a disclaimer (this information is from hearsay) or from online, or other articles. This might be considered the beginning of the end for a former great American company that was started in 1972 on a kitchen table. Orion Telescopes and Binoculars, would later purchase Meade, but would declare banruptcy a few years later.

The following is a Meade advertisement from almost 40 years ago as of 2024:

My local astronomy club (at that time) had a DS-16 which was a two-person job to set up.  I could take the 16-inch and use at any time. However, this thing was a monster, and where would I store this behemoth of a telescope? I didn’t and still don’t have a permanent observatory, and how would I set it up by myself? The 16-inch was definitely not for me!  The 10-inch seemed to be the perfect larger aperture telescope and with an equatorial mount. I had always liked the simplicity of a Newtonian, and an equatorial mount was a must.

Astronomy Magazine test and evaluation:

Astronomy Magazine tested a 10-inch DS-10A (The 10A was an updated version with a 2-inch focuser, setting circles and RA drive) with Astronomy Magazine giving the test mirror a rating of a B+.  

So, in February 1992, I purchased the 10-inch from Pauli’s Wholesale Optics, in Danbury Connecticut. It was Fred (the owner of Pauli’s) that recommended this telescope.

And now with over ~2,000 hours under the night sky and over 1,500 deep-sky pencil sketches and even more observing notes. I made the right decision and 33 years later as of 2025, I continue to use and enjoy this telescope, which is still in pristine condition. (See the photo below)

I have spent over ~2,000 hours at the eyepiece as of 2025. This would be the equivalent to 50 weeks working a job at 40 hours per week, which makes for a good prospective or comparison.

My other telescopes include a 102 mm refractor, 6-inch f/6 reflector, 80 mm f/5 refractor, Celestron 76 mm reflector First Scope (anniversary edition) and a couple others.

Shown below is the original mount, which I use when observing deep-sky objects that can’t be observed from my back deck. Only objects greater than +05º north declination (my house gets in the way) and allows me to use the Celestron CGE-Pro mount. It’s just not portable enough to use beyond my deck. Southern objects require that I use the original Meade mount, which I consider very portable.

The original medium-duty EQ mount:

For efficiency, I use both the RA and Declination circles to get me within ~1/2º degree of my target. At this point, I use a star atlas to zero in on my deep-sky object. Note the 6-inch Parks Optical declination circle and a fabricated index pointer.

The low pedestal mount is perfect for use with an astro-chair, when making observing notes and pencil sketches at the eyepiece. As for me, it’s impossible to observe and sketch while standing.

The original mount as pictured below is a medium duty mount, but is remarkably sturdy, due in-part to the very short pedestal. After spending so many years star-hopping to locate deep-sky objects, my favorite mount to use is the Celestron Pro mount, which I’ve had for only eight or so years. Again, can only be used for objects +05º north declination and greater, due to my house.

Both mounts, side by side for a comparison:

The Celestron mount is too large and heavy to take in and out of the house, so this Rubbermaid shed on my deck works well for storage. I also cover (inside the shed) the mount with a soft blanket and a piece of auto-marine fabric for extra protection.

The original mount is fairly easy to carry in-and-out, and can be stored in the corner of an extra bedroom.

A sample of a few of my sketches, using only a pencil, and a 5 x 8 blank notecard. My “humble sketches” are all raw sketches, as they appear to me through the eyepiece, without any computer enhancements. I try to make my sketches as accurate as possible, with any embellishing.

IC 5146 “The Cocoon Nebula” In Cygnus

NGC 2024 Nebula in Orion

M42: Orion Nebula Complex

M106 Galaxy in Canes Venatici

NGC 3079 Galaxy in Ursa Major

Messier 20 In Sagittarius

Messier 85 and NGC 4394

Comet Hale-Bopp: Charcoal pencil on black card stock, showing all three-tales; the gas tail, dust and anti-tail. April 1997

Messier 81 with spiral arms

NGC 7479 Galaxy in Pegasus

The Rosette Nebula

NGC 5689 Galaxy in Bootes

Messier 33

My wife (on occasion) uses the 10-inch to take photos of the moon:

I continue to ride, but “absolutely certain” I’ll not be able to ride another 100,000 miles. My rides in recent years are quite a bit shorter and much slower, but more fun.

Date: October 9th 2023:

I’ve went from an 80mm f/5 refractor to this 10-inch Newtonian in just a matter of days. So, I’m proud of the progress I’ve make, from never using a camera with a telescope, to “at least” an image of the moon. And all within a week!

I changed some settings on my camera, something I’d never done before. It had been set on ISO 100, for my everyday snapshots, and changed to ISO 400 this morning for this moon shot. I was amazed how much brighter the moon was when focusing through the camera using this 10-inch versus the 80mm refractor.

For sure a lot easier to focus with the brighter view due to the size of the telescope.

The field using this telescope is really narrow and small as this photo shows. Now I’ve got to figure out how to set the “exposure time” for some small and bright deep-sky objects.

I’m actually amazed that I could do this...and hopefully more and better to come. Debbie

Telescope: 80mm: 400mm Focal Length: f/5

Camera: Nikon D3300

Nikon T-Adaptor

Camera Setting: Manual

Vixen GP Equatorial Mount

The following photo was made after sunrise

Nikon T-Adaptor

I also made a photo as following using a 10-inch f/4.5 EQ telescope. Roger had using this telescope during an early morning 4:00 AM observing session of a galaxy. So, before bringing it back into the house, he suggested I try a moon photo with this telescope. This is my photo.