A 4-Inch (102 mm) Refractor Can Be An Excellent Deep-Sky Telescope: Finally Sirius B and Barnard’s Galaxy…

After almost 20 years, I finally replaced the original 6 x 30 finder with an 8 x 50.  My preferred method of locating deep-sky objects is by “old fashioned” star- hopping.  

Glenn Chaple, contributing editor at Astronomy Magazine:  In his March 2016 column “Observing Basics” Glenn wrote about a double star marathon, rather than the conventional Messier event.  This sounded interesting, so I knew that a larger finder would be essential for attempting such a project. 



At current, I’m working through Chaple’s Double Star list, taking my time to sketch, note the colors, check the position angle, and also drawing other stars within the field of view.  I’m also using an Orion correct image 90º diagonal.  I’ve always found a mirror image view via a standard 90º diagonal, whether a refractor or a Schmidt-Cassegrain impossible to scientifically draw any deep-sky object.  


Please note my double star system below.  With the employ of  “The Cambridge Double Star Atlas” by James Mullaney and Wil Tirion, I’m drawing a circle that matches my 8 x 50 finder and numbering it by the star sequence number.  This allows me to be quite a bit more efficient when locating the double stars.  

I’m enjoying taking my time and accumulating some good information to save, discuss, and share with others.

After my preliminary program, will I be able to go back and attempt the Double Star marathon….I’m not sure?  


All 110 stars are encircled in the atlas, with the designated double star sequence number being noted.  The number is also recorded on the observation card beforehand.  I can then quickly go to the proper atlas page with efficiency. 

I also wanted to share some of my deep-sky notes from years past.  Documenting what I have observed has proved to be very rewarding.  The following represents only a portion of my observing notes, sketches, and articles.     


Example of Pencil sketches using a No.2 pencil, a 5 x 8 notecard, with the colors being inverted via a scanner.  Some made with a 4-inch refractor, others with a 10-inch EQ reflector. 

Gamma Virgo - Revised

Scanned Image 161780000

Scanned Image 160920001

SN in M82 Revised -1

Pacman Nebula - NGC 281

I’ve always believed that a 102 mm refractor and a 10-inch reflector were the perfect combination of telescopes.  Not being one to be consumed by new equipment, I’ve spent most of my time observing rather than looking at new equipment.  The following vintage reflector is 25 years old, and I’ve had my 102 mm refractor twenty years.  I’m very proud to say, that I’ve spent 2,000 plus hours at the EP(‘s) alone over the past 25 years.  We can easily calculate this, which would be the equivalent of 50 work weeks @ 40 hours per week.  Hey….this is a full year of observing as related to a job.  This does not include thousands of hours spent cataloging notes and sketches, writing astronomy club NL’s articles, co-authoring the Las Vegas Astronomical Society Observer’s Challenge, articles for Orion Telescope and Binoculars, and other astronomy related sources.


Seeing Sirius B: 

“Finally….after more than 35 years, I was able to see Sirius B, better known as the “Pup.”

Date of observation:  March 14th 2012

Telescope:  4-inch (102 mm) Orion/Vixen f/9.8 achromatic refractor

Conditions:  Excellent seeing and transparency 

Location:  My moderately light polluted backyard in the foothills of North Carolina   

How did I become interested in this famous star and its faint companion?  

I purchased my first serious telescope in 1977, which was a 4 1/4-inch f/10, Edmund Scientific reflector.  Even though this was not my first choice for a telescope, it was the best my budget would allow at the time.  My first choice would have been the 6-inch Edmund f/8 EQ (Super Space Conquerer) reflector.  

I started reading anything and everything about astronomy, and was fortunate to find “The Edmund Sky Guide” by Terence Dickinson and Sam Brown.  In this book was a paragraph concerning Sirius and its companion which caught my attention.  Double stars were something new to me at that time, and my knowledge was very much lacking.  

Due to the extreme and overwhelming brightness of Sirius as compared to the much fainter companion, it can be extremely difficult to see the dimmer star.  I tried for at least a couple of years in a feeble attempt to see the companion (a.k.a the “Pup” or Sirius B) with my humble 4 1/4-inch Edmund reflector, but without success.   

During the fall of 2011, double star expert, astronomy author and lecturer, James Mullaney informed me that he had heard of an amateur being able to see the companion using a 4-inch refractor.  Mullaney and I have been good friends for at least 25 years.  We shared hand written letters discussing various double stars many years before the internet. 

I had pretty much given up on seeing Sirius B in 2012, thinking it was not possible with an amateur scope.  However, after hearing that an another amateur had been successful at seeing the companion gave me the idea that I should try again.  It was my plan to use the 102 mm refractor.  This telescope has allowed me to separate many close and difficult doubles over the years, often achieving or exceeding “Dawes Limit.”   

When Sirius B was at a relatively wide separation during the 70’s, again, I was using a spherical mirror, 4 1/4-inch f/10 reflector, not exactly the preferred telescope for accomplishing this feat.  

Last night, (March 14th 2012) using the refractor, I made preparations to observe Sirius.  After letting the telescope cool down for at least an hour, and making a few visual test….the seeing was excellent!  

Could this be the night?  The excitement was building as it had been a long time since first reading about Sirius and Sirius B during the mid-70’s.  

I had casually observed Sirius on many occasions over the years with a variety of telescopes, but never seriously looking for, or expecting to see the companion.  Afteadjusted my astro-chair, removing the diagonal, I started with a magnification of 83x, but to no avail.  I increased the magnification to 232x….keeping my eye perfectly still.  It was very surprising to see a beautiful airy disc surrounding Sirius.  It was quite amazing…no turbulence, and Sirius was almost pin-point, not the large bloated star that I was so used to seeing over the years. 

I looked very carefully for a few minutes, and there it was!   

After almost 40 years, I had finally seen the companion to Sirius, however, it should be noted I could not hold “Sirius B” constantly.  I must say, it was very difficult.  I glimpsed Sirius B the previous month (February 2012) but conditions were not all that good, and just had to have another observation to confirm my sighting.  

One of my first reference books many years ago, was “The Finest Deep-Sky Objects” by James Mullaney and Wallace McCall.   I had observed all 105 objects many times, accumulating over 600 or more, 3 x 5 note cards, complete with notes and sketches.  However, one of the objects of this list was missing…the companion to Sirius.  After the visual sighting of Sirius B, I now have notes and sketches of all objects listed in “The Finest Deep-Sky Objects.”

After seeing Sirius B, I went to bed smiling, as another observing goal had been accomplished.  It was a great feeling. 

Have you seen Sirius B, better known as the Pup?  Why not give it a try?  

Sirius. “A dazzling blue-white sapphire with famed white-dwarf companion!  Orbital period 51 years.  Now widening but still not an easy split most nights.  Mags -1.5/8.5  Sep.  7”  “The Cambridge Double Star Atlas”  by James Mullaney and Wil Tirion

I have always been interested in the possibilities of using a small telescope, especially a good quality refractor.  A refractor can present pin-point star images and a velvety black background which can improve the contrast of most deep-sky objects.  The superior contrast of a refractor can often times allow views of deep-sky objects that rival or even exceed larger telescopes of more complex designs.  

It should also be noted that a low surface brightness, extended object can often times be better observed at low magnification with a small refractor.  A good example of this would be NGC 6822 (Barnard’s Galaxy) in Sagittarius. 

“A weak glow but definite glow in 6 cm, where it appears elongated N-S and shows a very slight central concentration.  In 25 cm motion of the field helps in showing the low surface brightness galaxy, but it is difficult and ill-defined at best.” Observing Handbook and Catalog Of Deep-Sky Objects by Christian B. Luginbuhl and Brian A. Skiff.  

Finally…after almost 25 years (many years I tried with my 10-inch reflector) but had never been successful.  In September 2014, I was able to sketch and make notes of elusive galaxy, NGC 6822, using the 102 mm refractor.  Many amateurs seem to have little problem seeing this galaxy, but it has been difficult for me.  Much of my problem has been due to light glow from a pesky unshielded street light in close proximity to my backyard.  A dark sky is critical for locating and observing this faint low surface galaxy.  Another difficult object checked off my list. 

The following sketch was made using the refractor and nothing more than a No. 2 pencil with the colors inverted using a scanner.
Rogers NGC-6822

The following image:  courtesy of Dr. James Dire of Hawaii using a 190 mm Orion Maksutov-Cassegrain telescope.


The complete Las Vegas Astronomical Society Observer’s Challenge Report of NGC 6822: AUGUST 2014 OBSERVERS CHALLENGE – NGC-6822

One of my favorite all-time reference books: “The Observing Handbook and Catalog of Deep-Sky Objects” By Christian B. Luginbuhl and Brian A. Skiff

I like the descriptions by the authors describing the views with various telescopes, especially with a 60-mm refractor.  This causes me to want to follow their observations and see what’s possible for me using a 60 mm refractor, however, I don’t have one.  No problem.  I have a home-made 60 mm stop-down mask for use with the 102 mm refractor.  This allows me the opportunity to observe the object with a 60 mm refractor, without having to add another telescope.  I can then make visual observing notes and sketches for two scopes.  

I purchased the 102 mm f/9.8 achromatic refractor in 1997.  It’s easy to set-up, and when the night gets late, it’s a lot easier to take down….far easier than my 10-inch equatorially mounted reflector.  


My older brother purchased a 60 mm f/15 EQ Jason Refractor in the mid-60’s, when I was only twelve years old.  This was the telescope that got me interested in astronomy.  I would set it up in a weedy field beside of my house in a very rural area of Western North Carolina.  I had difficulty finding anything other than the moon, Venus, Saturn and Jupiter, but eventually my observing skills did improve.  I’m really glad that I persevered and stuck with it. 

Maintenance of a refractor:  I have always kept the lens capped on the 102 mm refactor, when not in use and the OTA is always stored in a padded case.  In the eighteen years that I have owned this telescope, the objective lens has never required cleaning.   The objective lens is also permanently collimated, and was in perfect collimation when I received it.  There has been no change after eighteen years of use.   

For most part a refractor is much more durable and able to suffer less from mishandling and rough treatment than reflector’s and catadioptric telescope’s.   

A very high quality 4-inch refractor during the 50’s through the 70’s, had to be a Unitron, with the standard f/15 focal ratio.  The long focal length was necessary for an achromatic refractor telescope… to reduce false color.  This telescope could be obtained with either of two mounts.  One being a field tripod with wooden legs.  The other….a massive bell-shaped pier with a mechanical clock drive.  The latter was designed for a permanent location.  A 4-inch f/15 refractor with any type of equatorial mount for most part should not be considered a portable instrument.        

John Mallas who co-authorded “The Messier Album” with Evered Kreimer, used a 4-inch f/15 Unitron to examine all Messier objects between 1958 and 1962, from Covina, California.  This is a fabulous book and I still use it as a reference quite often.   

The modern era of refractor telescope’s arrive:

In recent years with the advent of exotic glass, better anti-reflection coatings and short focal lengths… like the slide-rule, the day of the 4-inch and larger f/15 refractor was over.     Roger Ivester

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