Archive for the ‘Uncategorized’ category

NGC 4565 via 32-Inch Telescope: By Guest Host, Mario Motta

May 19, 2021

The APOD image today is NGC 4565, an incredible image from the CFH telescope on Mauna Kea (An 8.0 meter mirror, one of the largest scopes in the world), see the image at the bottom of this email.

Not the same level of fine detail of course (I am “only 0.8 meter” in size or 32-inches) but, it does compare nicely. I am pleased. It’s great when you can compare your image with a major “professional” telescope, for sure!

For a comparison, I’ve posted both images together: Roger

I’m especially happy that the color is almost a match, as I’m a stickler to “get the color right”, and based on the professional image, I think I achieved this.

Much of this is not only “just good” optics, but good processing.

Despite imaging since the 1980’s I am still learning, and have adopted some recent techniques in PixInsight which helped get the color exactly correct, and squeeze out good detail.

Speaking of the CFH (Canada-France-Hawaii) telescope, I visited the facility some years ago, its mirror was cast in the Arizona mirror lab by Roger Angel who perfected the technique of casting and polishing these behemoth mirrors.

One of his mirror makers, Peter Wangness left the lab to set up his own private mirror making commercial business. He says I was his first customer, when he cast my 32-inch (0.8 meter) scope as a favor, and at cost as a test back in 2004. He pre-made the rough curve before I ground and polished it.

To minimize cost and engineering, he simply took the plans of the 8 meter mirror and shrunk it down to 0.8 meter…so my 32-inch is in effect a “1/10th” model of the CFH telescope. Something I have always been very happy about.

For all reading this: you can now compare directly an image from the 8 meter CFH, and its 1/10 scaled model…which is my scope.

Mario Motta

https://apod.nasa.gov/apod/ap210517.html

The Southern Cross by Commercial Airlines Pilot: James Yeager

March 29, 2021

Jim Yeager has always allowed me to use any of his aerial photos, which over the years have included, a beautiful photo of the Barringer Crater in New Mexico, covered with snow, and the Mount Potosi Observing Complex in SW Nevada. Both of which I’ve used in previous blog articles and other.

I really like the following image, as I’ve never seen the Southern Cross.

Jim’s notes and photo:

Here is somewhat of clear picture taken with an iPhone using a 3 second exposure on a descent out of 41,000 feet about 100 miles north of Lima, Peru.

You can see Alpha and Beta Centauri pointing to the Southern Cross.

The residual cockpit lights, moonlight behind us, and the haze of high altitude cirrus kept us from seeing the Magellanic Clouds.

Other aerial photos by Jim Yeager:

https://rogerivester.com/category/mount-potosi-observing-complex-in-southern-nevada/

https://rogerivester.com/2016/12/06/aerial-view-of-meteor-crater-compliments-of-james-yeager-pilot-american-airlines/

iOptron CEM70 – Center Balanced Equatorial Mount: By Guest Host: Mario Motta

March 19, 2021

I was considering making a take-apart mount but finally realized I could not build one light enough with all the features I desire, so, I purchased an iOptron CEM70G mount. (guilt for an amateur telescope maker!)” Mario Motta

My story:

Up to this point I have always built my own equipment, such as my 32-inch f/6 reflector telescope in Gloucester, Massachusett, which is my main telescope for imaging, and in a dome attached to my house.

At the end of this year I will be retiring, and per my wife’s wishes will be spending winter months in Naples Florida at our second home. However, in my Florida location I can’t build a dome for a number of reasons. This is due to (hurricanes, building restrictions, etc.)

I was considering making a take apart mount but finally realized I could not build one light enough with all the features I desire, so, I purchased an iOptron CEM70G mount. (guilt for an amateur telescope maker!)

The head weighs only 30 pounds , tripod another 30 pounds, for a manageable weight, yet, tracks very well (3 arc sec error periodic error), is very sturdy, can carry a 70 pound weight load, so it can handle up to a 14-inch scope easily. It has a built-in polar scope alignment guide scope. It even has WiFi, and 4 USB ports. 

Why the center mount instead of a german equatorial or a fork? At 43º North latitude (my 32-inch sits in a handmade fork) or german equatorial which works fine.

Look at the following images as following, “German equatorial”and see that at 43º, the center point of gravity pushes through the main mount, and weight of scope and dec axles pushes down the polar axle, a fork also works the same way.

However…at 26º N latitude, the weight of the scope and counter weight is very far forward, putting all the stress on the forward polar bearing.

Not very stable: A fork overhangs badly.

Now let’s see what a center mount does:

At 43º North latitude, it works well, but all the thrust is on the rear bearing and a german equatorial may be best. Now see what it looks like at 26º N latitude. (see image center mount) Here the weight of the scope is directly over the center of the polar axis, the weight is evenly distributed on both bearings, thus can handle a heavier load with less stress, overall an ingenious design. In reality this is nothing new, what this is… is a miniature English “cross axle mount”.

I built one for a 16-inch scope in the 1980’s and it worked very well.  See the following photo following the M42 image:

In summary, if far north, fork or german equatorials are best, but if closer to the equator, a center mount or cross axle is best.

An Image of my new mount is attached, with a small 6-inch RC for test purposes. My plan is a 12 -14 inch on this mount. The following Image of M42 (test subject, not a long great image, but more of a proof of concept for location and mount. (this image was made unguided).

The English Cross-axle I built in 1985, with my older 16-inch f/4.5 home made telescope.

I’m proud to say: My current 32-inch f/6.5, and every part is hand-made

How to Choose Your Telescope Magnification – Sky and Telescope Magazine: By Al Nagler

March 9, 2021

One of the best articles I’ve ever read concerning the calculation of everything involving telescope eyepieces.

https://skyandtelescope.org/astronomy-equipment/choosing-your-telescopes-magnification/

I was fortunate to meet Al Nagler a few years ago. Such a nice guy….

My Quest to Observe the Entire Herschel Catalog: By “Guest Host Larry McHenry” From Pittsburgh

February 18, 2021

It is Done!

As of May 13th, 2020, I have now completed observing all 2,482 identifiable objects of the Herschel 2500 Catalog.

My last catch was ‘H II-840’ a pretty little one-arm galaxy – NGC3978 in the Great Bear – Ursa Major.

The idea for this ‘Herschel Objects’ project started back at the end of 2012, as I was wrapping up a Constellation survey based on the “Night Sky Observers Handbook“. I realized that my observations would already include a large number of the Herschel-400 objects. So after identifying all the ‘400’ objects that I had previously observed, it only took me less than a year to finish the ‘Herschel 400’ list. For this phase of the project, I utilized the Astronomical League’s “Herschel 400 by Constellation” list and their “Observe the Herschel Objects” booklet. I then downloaded the AL’s “Herschel-II” list of the next 400 objects and began hunting those. 

By the fall of 2016, I was down to the last 60 objects and was wondering what my next project should be. Flipping thru some old “Sky & Telescope” magazines, I ran across an article from the August 2012 issue by Rod Mollise on observing the entire Herschel Catalog of 2500 objects using a deep-sky video camera. This was the inspiration (and project), that I needed, as I was already a videoastronomer, so I began a multi-year effort to observe the entire Herschel Catalog.

So today, we’ll discuss what I’ve learned during that journey among the Herschel Objects. Hopefully, when we are done, you will find them as interesting to hunt as I do.

First, a little background on the Herschel’s:

After the Messier List, the Herschel Object’s are the next most observed deep-sky objects. 
Most amateur astronomers know them by their NGC numbers, but they started out as a list created by British amateur astronomer William Herschel and his sister Caroline, two of the greatest astronomers from the ‘Age of Enlightenment’, which marked the birth of modern science.  

From 1782 to 1790, the Herschel’s conducted systematic surveys of the night sky, in search of “deep sky” objects, and discovered over 2500. Herschel used two telescopes for his survey, a “20-foot Reflector”, which had an 18.5” speculum-metal mirror, and later the great “40-foot Reflector” with a 48” mirror.  Most of Herschel’s recorded observations were made using the ’20-foot’ telescope, as the larger ’40-foot’ was cumbersome to use and suffered from tube current distortions.

Herschel’s telescopes didn’t have clock drives to track the stars, so instead, he would point the telescope to the meridian and let the Earth’s rotation carry objects across his field of view while he was up on a ladder observing. William would then call down to Caroline, at the bottom of the telescope, whenever he saw anything interesting, and she would write down his descriptions and time and where the telescope was pointing. Caroline would then quickly read this back to William and he would confirm the observation while the object was still in the eyepiece. This method allowed them to observe and record a nightly east-west strip of sky. The next day, the two of them would use their recorded observation to calculate the objects position on a star atlas. They would then move the telescope’s elevation up or down, in preparation of the next nights survey run.  Using this method, they were eventually able to observe all of the sky visible from England.

The Herschel’s observing technique of surveying, cataloguing, and classifying what they found, and then using that data to try and understand the structure of the universe, has become one of the most important tools of modern astronomy.

How I accomplished the project:

So back in 2016, as I began a multi-year effort to observe the entire Herschel 2500 Catalog, the first thing I needed to do was come up with a list of the Herschel Objects! While during the process of William and Caroline Herschel’s original recording and publishing of their observations from 1786 thru 1802, along with subsequent reprints and revisions over the 19th century, there have been a number of discrepancies over misidentified or non-existent objects. Depending on the source, of the Herschel’s 2500 objects cataloged, there are anywhere from the low 2400’s to over 2500 actual objects. Mark Bratton, in his book “The Complete Guide to the Herschel Objects“, gives a good review of the issues and historical attempts to rectify Herschel’s list of objects. He eventually settles on there being only 2,435 identifiable Herschel Objects. (I utilize his book’s visual descriptions and DSS images to help in comparing and confirming my personal observations). In addition to the above book, I also utilized George Kepple & Glen Sanner’s “Night Sky Observers Guide Handbook” and internet resources ‘WIKISKY‘ and ‘The NGC/IC Project’ to validate my observations. 

To help tackle this project, I downloaded several lists from various websites, and after combining, distilling, and sorting, I generated a personal spreadsheet/logbook to help in my tracking & logging. The core data for my logbook comes from a list of 2,482 Herschel Objects by Steve Gottlieb. 


All of my Herschel Object observations can be found in their individual constellations in my website under my ‘Constellation Tour’ page. To see the entire list together, I’ve created a specific page for the Herschel Project: “Herschel Tour”  

http://www.stellar-journeys.org/herschel-tour.htm


Over the course of this project, I have spent a total of 239 nights working my way thru observing all of the Herschel Objects. 

Even though I really didn’t get serious about completing the list until 2012, my observations stretch all the way back to 1984. 

All of the early observations are visual sketches, (78 objects), made at the telescope eyepiece, with everything after 2001 using videoastronomy (EAA) short-exposure lucky imaging technique. I eventually used a total of ten different telescopes for this project. Six visually – 80mm f3.2 refractor, 8″ f4.5 dob, 10″ f5.6 dob, 13.1″ f4.5 dob, and a 8″ & 12″ SCT at f10. The dobs and small refractor were manual telescopes, with the two SCT’s being motorized, but all required using star-charts and star-hopping techniques to locate the objects. 

For the videoastronomy observations, I used four telescopes – 50mm f3 refractor, 80mm f6 refractor, 6″ RC at f9, f6.3 & f5, and a 8″ SCT at f10, f6.3 & f3.3.  All these telescopes were on either SCT or CGEM mounts that could track and later utilize GOTO.

The cameras used were a StellaCam-EX (2.5 seconds exposure), StellaCam-II (8 seconds exp), a Samsung SDC435 (8 seconds exp), a peltier cooled, wireless controlled StellaCam-3 (unlimited exp), and finally a ZWO ASI294MC Pro camera used in EAA mode (generally for around 120 second exposure). 

While I prefer going to dark sky locations, such as Pennsylvania’s Cherry Springs State Park, for my observing, utilizing near-realtime deep-sky videoastronomy cameras has allowed me to pull in faint 14th magnitude plus galaxies not visually possible from my backyard observatory located within 10 miles of downtown Pittsburgh, PA. This greatly expanded the number of clear evenings available for working on this project. 

Having spent time over the past several years following in the Herschel’s tracks, you could begin to pick-up on how they were doing their observing run for that particular night back in the 1780’s, slowly letting the Earth’s rotation bring each object into their sweep. Using today’s modern equipment, there’s no need to wait; all you had to do was hop down the sweep path to the next observable object. When you think about that, it’s sort of inspiring to think that in your own way you are following in their footsteps!

In retrospect, I have learned a lot about the lives of William and Caroline Herschel, along with the objects that they discovered. While there are a number of nice large, bright objects including galaxies, star clusters, and nebula, the majority of Herschel’s objects are small, faint, dim smudges of galaxies. It gives you an appreciation for the brighter Messier Objects. Still, there is a wide variety of shapes and sizes of interesting deep sky objects for any type of telescope. I now have a much greater respect for all those faint fuzzies and the work of the Herschel’s! So I encourage everyone to get out tonight and try your hand at finding and observing the deep-sky objects of William and Caroline Herschel!!

An examples of my many sketches:

My equipment used for this project: Telescopes, observatory and camper : Larry McHenry, Pittsburgh, Pa


Hope you enjoyed my story: Larry McHenry

Herschel 400 Notes: By “Guest Host Sue French” From New York

February 16, 2021

Sue and Alan French

Click on to enlarge: The latest Herschel 400 book (above) from the Astronomical League. Consider ordering your copy today.

Reiland 1: Obscure Cluster Plus Nebula in Cepheus

October 18, 2020

Earlier this year (Spring 2020) I was communicating with Tom Reiland of Pennsylvania. Tom was recently a recipient of the Astronomical League, Leslie Peltier award, and a lifelong amateur. He mentioned to me about a cluster in Cepheus which he discovered back in the 80’s, and was given the name, Reiland 1.

Right Ascension: 23h 04m.8″ Declination: +60º 05

The following image provided by Mario Motta from Massachusetts: 32-inch Reflector; 40 mins asi6200 camera

The following images Provided by James Dire of Illinois: 8-inch f/8 Ritchey-Chretien telescope with a 0.8x FR/FF and a SBIG ST-2000XCM camera. Exposure 60 minutes

An excellent report by Mike McCabe from Massachusetts: Click on the above link.

October 2020 New Moon In Jordan by Anas Sawallha: 19 Hours 36 Minutes and Also the Last Crescent Moon of June 2021

October 18, 2020

I was happy to have received an email (September 17th) from my astronomy friend in Jordan, Anas Sawallha with this 19 hour 36 minute new moon photo. Thank you Anas.

Supplemental: June 9th 2021

I’d would like to share with you the photo I took of the last crescent of shawwal taken during daytime with CCD camera.

Date: June 9th @ 8:30 AM local Jordan time…

Anas Sawallha

The “Great Lensnapping” By Guest Host: James Mullaney

June 17, 2020

Roger, I don’t know how many of your readers have heard of the “Great Lensnapping” that happened at the original Allegheny Observatory in Pittsburgh in the late 1800s.  

My beloved 13-inch Fitz-Clark had it’s objective lens stolen and held for ransom.  At the time, it was the third largest in the world!  (Now it’s the third largest in the current Observatory.)   

Samuel Pierpont Langley was director at the time and refused to pay anything, as no telescope in the country would then be safe from theft.  He finally met the thief at a hotel in a Pittsburgh suburb – the thief agreed to return it if Langley didn’t prosecute.  He subsequently found it in a waste basket at that very hotel.  

The lens was pretty well scratched up and Langley sent it to Alvin Clark for refinishing.  Thus the dual name Fitz-Clark.  As I’ve stated before, it is without question the finest visual telescope I’ve ever seen or used bar none!

 

“Celestial Harvest” The Book: By Guest Host, James Mullaney

May 18, 2020

CELESTIAL HARVEST:  HOW IT HAPPENED

When I first become a budding stargazer at age 14 and anxious to see everything in the sky, I consulted a number of supposed “showpiece” lists – and soon became disappointed and frustrated.  Many were obviously compiled based on photographs and not visual impressions, including objects like the Horsehead Nebula.  So I decided to survey the entire sky visible from my home (back then) in Pittsburgh.  I wrote to my idol Walter Scott Houston (Scotty) and told him of my plan.  He kindly replied saying he was afraid this was an impossible project in aesthetics – but then, characteristically, said “Go for it!”

As a result, nearly 50 years later and over 20,000 hours spent at the eyepieces of many dozens of telescopes of every size, type, and make from 2-inches to 13-inches (Allegheny Observatory’s famed 13-inch Fitz-Clark refractor) in aperture, in 1998 I self-published Celestial Harvest: 300-Plus Showpieces of the Heavens for Telescope Viewing & Contemplation (later reprinted by Dover Publications in 2002).   Thus, my lifelong labor-of-love came to be born!

James Mullaney