My First View of Saturn

On the Cloudy Nights discussion board for amateur astronomy the topic came up (as it does now and then), “What was your first telescope?” Some people who are newer to the hobby began with very modern instruments. Other replies came from long time stargazers who posted images of classic refractors from the 1970s. So far, 24 hours later, my post displayed the oldest instrument. I mentioned that I first saw Saturn with it. By running the celestial clock back, I was able to pinpoint the date: it was my mother’s birthday, August 2, 1959. The grown-ups were having a party and one of the doctors, a young resident, said, “That looks like a planet. Get your telescope.” I set it up on the backyard picnic table. He sighted it in and announced “Saturn” and then told me to find it. I did. It changed me more than did my first view through a microscope. 

He also pointed off to our right (west) and said, “That looks like Jupiter.” But there was nothing on which to prop the tabletop telescope. He told my mother that I needed a proper telescope and that happened some months later. It was a Criterion 4-inch reflector. But lacking any more guidance, I cannot remember having seen anything with it, the Moon maybe, but stars are just stars unless you have a proper target such as the Orion Nebula. Even though I had a membership in the Cleveland Museum of Natural History and attended many planetarium shows, I never did any productive observing. 

 

Years later, 1981-1983, I took some directed study classes in celestial mechanics at Lansing Community College. In 2020, I completed an online class in astrophysics through the École polytechnique fédérale de Lausanne via edX. Since 2020, I have been editing This Month in Astronomical History for the Historical Astronomy Division of the American Astronomical Society. 

 

In 2014, my wife and daughter bought me a telescope for my 65^th birthday. I chose an instrument that was most like the Criterion 4-inch reflector, a Celestron 130mm Equatorial mounted Newtonian reflector. I did not use it much for five years because I found the German equatorial mount cumbersome and the process of collimation frustrating. When I did use it, I benefited from the experience. It gave me many views of Saturn (and Jupiter and Mars), Messier 44 the Beehive Cluster, and on 2 December 2018, my first view of the Andromeda Galaxy.  

 

After donating it to the Goodwill, I bought myself an Explore Scientific 102mm refractor in October of 2020 (and later a better altitude-azimuth mount for it). That has been my “grab-n-go” these past two-and-a-half years. Right now, Saturn rises after 5:00 AM and it will be above the tree line by mid-May.

 

PREVIOUSLY ON NECESSARY FACTS

Irene Louise Babos Marotta Joseph 

Tarzan, the Amazons, and My Mother 

My Grandmother and Science 

 

PREVIOUSLY ON NECESSARY FACTS

Merry Newtonmas 2020 

Saturn-Jupiter Conjunction 2020  

Binary Star Project 

Recent Astronomical Observing  

Familiar Sites, Familiar Sights

Three constellations on the ecliptic actually look almost like what they are supposed to be: Leo, Scorpius, and Taurus. Those probably go back to 5000 BCE if not earlier. By 1200 BCE, other constellations had been mapped by civilizations in Mesopotamia, Egypt, and China.  

22 January 2023 05:30 AM CST

The Romans were obsessive about order. Conforming with 12 inches to the foot, and 12 ounces to the pound, and 12 gods of Olympus, they created 12 zodiac constellations. The Claws of Scorpius became Libra.

Corvus 4 May 2021 23:00 to 23:20 Hours

Corvus 6 May 2022 22:12 Hours CDT

Scorpius 14 July 2015 22:43 to 22:48 CDT

Zuben Elgenubi 01 Feb 2021 05:35 to 06:00 CST

Xi Scorpii 19 June 2022 23:30 CDT

Xi Scorpii 19 June 2022 23:30 CDT

In The Odyssey, the hero is told to steer his raft by the Bear who looks at Orion. The Bear, Calypso says, is also known to others as the Wagon.

PREVIOUSLY ON NECESSARY FACTS

 

The Andromeda Galaxy 

Binary Star Project 

Two Deep-Sky Targets 

Neutron-Irradiated Dimes 

Celestron AVX Mount Review (Part 2)

So far, after four nights, I am something less than sanguine. The smart drive mount works well enough, given some problems noted below. I have about 20 more pages of user manual to understand. That said, after the first engagements over four nights, the Celestron AVX go-to mount did the job after some angst and uncertainty. The "Information" and "Identify" buttons do make this a teaching tool, like an interactive planetarium with the actual sky above you right now as you see it. Tracking works well. I finally had the opportunity to sit in a chair and look at Jupiter for long minutes without having to turn a cable control knob. Not much happens quickly in the sky, but the rotation of Jupiter is one of them. 

I need to learn the faux Arabic names of the stars - Caph for beta Cassiopeia, Mirfak for alpha Persei, etc., etc. Some I know: Betelgeuse, Rigel, Deneb, maybe a dozen easy ones, on top of other common names such as Antares and Polaris. However, here the entire database of Named Stars does not allow inputs such as delta Scorp. You can, indeed, choose epsilon Lyrae or eta Cassiopeia and many others from the list of Double Stars. 

Celestron AVX Mount and Tripod 
with
Explore Scientific 102 mm
f/6.47 Achromatic refractor

With a computerized telescope, I am reminded of Jurassic Park: All the problems of a major zoo and a major theme park. Here, you have two servo controlled motors and a warehouse of information databases, and all of it under the same menuing on a telephone style keypad, going back to the overhead crane come-along paddles of the 1970s. The UI/UX (user interface/user experience) people make their best guess and you learn the system they deliver.

 

The mount and tripod do thread up well. The mount pre-locks into place with two screws that meet on a flange. They call it "fine setting for azimuth" but it puts the mount in place for the central shaft screw that (1) secures the mount to the tripod and (2) secures the leg brace and accessory plate.

 My other experiences included two large (8-inch and a 10-inch) Meade catadioptric telescopes. Integrated with the lens tubes as units, the mounts were difficult to set into the tripod. Getting the threaded rod into its threaded receptacle was a risky chore because I had to be careful not to lose control of the 35-lb telescope while tilting it and rocking it back and forth atop with one hand to find the engagement with the other while crouched below.

 I have taken this apart and set it up four times now and it always goes together easily. (A couple of years ago, I replaced the thermostat in my Civic and the one-hour job took eight over two days with two installs to get it right. So, I'm a tough test for mechanical procedures.)

 

I had some problems. With Arcturus still above the tree line to my west, I chose that star for the first alignment and the telescope slued about a 90 degrees wrong northward and 90 degrees wrong in altitude. I powered down and waited. While it was unpowered, I checked north again. I use my cellphone aligned on the telescope. This is my backyard. I have been here ten years. I have recorded Polaris as a binary. I know north. But okay, I did it again, then powered up again. 

 

10 September 2025 hours- I chose Arcturus again and this time it went well. 

2027 hours -  The next star was Antares. While jogging the instrument to align the star in the field of view, the paddle stopped responding. So, I waited, and five minutes later (2032) I selected Antares again and the mount aligned near the star and I brought the star into the center of the field of view at higher magnification. 

2032- I chose Deneb for the 3rd star. 

 

[Went in for dinner and to sleep and woke up about 3:00 AM.]

 

11 Sept 2021 0320 hours. Checked star charts before setting up because I could not see many stars up that I know by name. 

0406  hours Aligned on Hamal (alpha Arietis) and Aldebaran, which was finally above the tree line to the east. 

 

Chose the Solar System key on the pad and selected Uranus. Used magnifications 38, 77, 82 and 165 from 17mm and then 8mm both with and without 2X Barlow to repeatedly check the field, jog the instrument, select Uranus again, and again jog the putative target to center. If there was a planet in there, you could not prove it by me. The target offered was granted steadier and more circular than a star, but not by much. I have seen stars like that, especially when close the Airy limit. It was not much bluer. 

The heaviest attachments:
a 40 mm Ploessl ocular
atop a 5X focal extender.
Total instrument weight is
below 14.3 lbs (6.5 kg).
The mount is rated at 30 lbs
and that is an occlusion.
(See Part 1.)

11 September 2021 2013 hours - Set up.

2050 hours - Aligned on Antares and Arcturus. No problems. Added Deneb and Nunki (now that I know which one is Nunki). 

 

2051 - Chose the Deep Space key on the pad and then selected Messier, and entered 013.

2055 - Messier 13 the Hercules Cluster observed with 14mm and 2x Barlow for 94x. This was a win for me because I have been unable to find it on my own by star-hopping. 

My intent here is to learn the locations of this and similar targets from the computerized go-to and then use a manual mount with a different telescope to find the target by star-hopping.

2105 - Messier 6, an object that I know.

2107 - Messier 7 - Ptolemy cluster well I know from previous sighting and manual tracking. It is a naked eye target.

 

12 September 09:19 hours.

Finishing this report. Last night after the 0100 AM session, I brought in  the ocular kit, the power pack and the hand control. I covered the mount with a plastic garbage bag and covered that with a cloth-like water-resistant shower curtain. Nominally, the ambient temperature was 10 degrees F above the dew point, but weather is local and I know from previous sessions that my backyard gets wetter sooner. Celestron warns that the power pack in particular is not waterproof, and I take that to mean that nothing else is, either. This morning, the porch was damp to the touch, but the mount and tripod were dry. I brought them in.

 

After setting up in the living room, I used a Phillips screwdriver and a hex wrench to re-tighten the Right Ascension and then loosen and reset the Declination lock latch. 

 

The forecast is for clouds and rain this week.

 

PREVIOUSLY ON NECESSARY FACTS

 

 Misconduct in Science and Research 

 20% of Scientists are Crooks

 Retraction Watch 

 Four Books About Bad Science 

 Junk Criminology as Pseudo-Science 

 Criminalistics: Science or Folkway?

 

Product Review: Celestron AVX (“Advanced VX”) Mount and Tripod

This is an on-going project.  My summary opinion after three nights is that for the observer, this is a planetarium show. You press the button, it shows you a star. It does make viewing easier. You spend more time looking at things rather than looking for them. These computerized "go to" motorized mounts are intended for photographers. Astrophotography--not my hobby--is all the rage, having grown over the past generation to eclipse mere stargazing.  

The mount and tripod (just “mount” unless otherwise specified) arrived on Thursday, 2 September. However, I had a weekend project, contracting to edit a report for the Mayo Clinic. So, I put off setting it all up until Monday, the 6^th. I also bought a battery for it, which arrived the day before and which I charged. I inspected the mount physically, and assembled it in my living room. I had to stop at the two-star alignment. 

I bought the mount to work with two lightweight refractors, 12 lbs and 17 lbs. I also have a heavier (22 lb: 10 kg) reflector that I can put on this for collimating the mirrors. However, that telescope is too heavy for this mount, even though it is rated at 30 lbs (14 kg). For one thing, it comes with a 10-lb counterweight. That is something that you have to keep in mind when you read sales specifications: you have to subtract the counterweights from the specifications or add them to the weight of your payload. The saleslady at the retailer Woodland Hills Camera and Telescope of Los Angeles warned me that with eyepiece and finder, the 22-lb telescope would be too much for the motors.

 

I found the instructions to be clearly written, but not easy to read and understand. The small type and run-on paragraphs save space, probably left over from the days of saving paper, but make reading difficult. 

 

My first adult telescope was a Celestron EQ-130 and I borrowed two larger instruments on German equatorial mounts from the local club. So, myself, I would start by aligning to North. I know from aviation that magnetic north is not true north and I know from astronomy that Polaris is 89 degrees and almost 16 minutes, but not at true north. You get close enough. The point here is that Alignment is on pages 14-16 but Polar alignment is on page 29. 

 

One item was missing. The chart and illustration did not indicate the RJ-11 input port for the declination control. I spent about 15 minutes searching, eventually with a flashlight. The port is behind the declination motor (of course) but hidden from view. All of the stamped surface labels are as flat black as the body they are on. Some of the RJ-11 auxiliary ports do have white press-on labels. 

 

8 September 2021

The next clear night was the 8^th. I set up outside mindful of where I expected the neighbors’ yard lights to shine. As soon as I saw Vega and Antares (after 2007 hrs), I performed the two-star alignment as indicated. The menus will take some getting used to but at 2047 it was aligned. I selected the first Double Star target offered, 17 Cygni and sure enough, in the viewer was a classic double star.

At 2050, Albireo; at 2051 epsilon Lyrae and I increased the magnification to 165X (8mm with 2X Barlow) and verified the double-double. At 2106 M22 was questionable: I could see a patch, but I was not persuaded. However, it tracked to Jupiter and then Saturn easily enough. So, I turned to a tough problem, Messier 4 just west of Antares. I have never been able to locate it manually. I did not locate it this time, either. I pressed Deep Sky and up-down arrowed to Messier and entered 004 and the telescope slewed and stopped. But I did not see anything in the field of view. 

 

I could not figure out how to move the telescope manually. I kept hitting Back and tried the arrows, but it would not move. (On the shop floor we “jog” robots, but in astronomy “slue” telescopes which Celestron spells with the variant “slew.”) Anyway, I entered “No joy” for M4.

 

I also noted that the telescope was not perfectly aligned. That problem reappeared often over the next two nights. 

 

I went inside for dinner and at 2326 powered up again. I had to realign from the start. Two nights later, I still have not found how to store the settings. It does remember some of them, but not all. Again, I chose Vega and Antares and then added two more calibration stars, Albireo and Deneb. I also found the Menu button to change the displayed list of stars. 

 

Alternating the 17mm ocular (38.8X) and added 2X Barlow, I took the Sky Tour offered by the keypad. 

The first stop was Sigma Cassiopeia, but I did not know what I was looking at. It was just a starfield. The pair did not stand out for me. 

 

At 2332, I went to the Ring Nebula (Messier 57) and at 77.6x I noted it as “very faint but believeable.”

 

2339 – Double star Zeta Lyrae, check. 

2342 – Andromeda Galaxy (M31), check.

However, I had to jog the telescope into position. M31 was off to the far right. I apparently touched Back or something and I was able to slue the telescope to bring the object into the center of the field. At 77.6x M31 was very faint, which I attribute to the poor skies.

 

2348 – Omicron Capricorn, another binary, viewed with 13mm and 2X for 101.5x, but, again, I had to jog the instrument to bring the object into the center of the field of view.

 

I took everything down and brought it indoors. 

 

9 September 2021

 

In the morning, I took it all apart and put it all into its shipping cartons intending to find out what the returns policy is at Woodland Camera and Telescope. In the afternoon, I uncrated everything and set it up outdoors again. The second night went better.

 

1247 hrs – chose to compare M22 with M28 to verify my previous journal entries. (See “A Good Night Observing” from 1 August here. And I have an M22 coffee cup for the shoreline drive at Traverse City, Michigan). Also noted M54, M70, and M69 as targets moving east to west across the lower tier of Sagittarius.

  

I fought with the telescope over alignment and finally went in, got the old Twilight Mount, and recentered the finder scope by targeting Jupiter. From that point on, the problems were not with me. Alignment is a two-step process. You pick the target from the menu and slue to it, then jog the telescope to put the target in the center of the finder. Then you press Enter. Then in a fine-tuning mode, you center the target in the eyepiece field of view and press Align. That’s why I went in for the old mount. I wanted to be dead-nuts-on because it wasn’t going well from the start. 

 

At 2245 I ran a two-star alignment with Vega and Deneb and added Albireo and Altair. I suspect that these are all too close and the best alignment is with stars as far apart as possible. Oddly, I never see Polaris as a menu item. 

 

At 2257: The mount positioned the telescope at M54, M69, and M70.  All were ghosts, mere hints. From numismatics, I learned optimistic grading of coins, so I could almost accept these details, but I logged all three as No Joy, again, probably because of the poor seeing conditions.

 

I then tried M25 and M18 both in Sagittarius and both empty fields which I logged as No Joy. Again, I could not get the mount to release control of the paddle to me. So, I moved on and selected Messier 30 in Capricorn. It was faint but discernable. Next were M11 in Scutum and M27 in Sagitta. The open cluster M29 near the center of Cygnus was one I stumbled upon previously and was easy to accept.

 

M30 in Capricorn was just a starfield, not the globular cluster I expected. The positioning might have been off as it would prove to get worse. I selected M27 the Dumbbell Nebula but I am not sure that it was in the field of view. Similarly, Messier 11 the “Wild Duck” cluster in Scutum merited only a question ? mark in my notebook.

 

At 2341, I selected eta Cassiopeia from the menu and it was just plain wrong. I lined it up in the finder, jogged to it with the controller, and focused in nicely. When I selected it from the menu the telescope slued to some nearby place of lesser interest. 

 

At 2350, I chose Polaris from the menu and it was not in the field of view.

 

At 00:10 on 10 September, I jogged telescope to Polaris and tried a selection of higher magnifications to seek the binary companion. Even at 194X (17mm with 5x focal extender), I got a nice Airy disk, but no companion. This needs more aperture and I have recorded with an 8-inch Schmidt-Cassegrain borrowed from the local club.

 

00:30 I slued to a bright star in the high south, and pressed Identify and it was, indeed, Altair.

 

The weather brief put the dew point far below the 5:00 AM low temperature. So, I covered up the telescope, went indoors, and set my alarm for 02:30.

 

At 0251, I chose Uranus from the menu and was treated to an empty space with a few stars in the periphery, none of them bluish. So, I chose Jupiter. It missed completely, no mistake about that. Also, even though I left the telescope unattended for two hours, when I came back out, it was not in sleep mode. 

 

Writing this and searching through the PDF of the user manual, I found this gem:

Re-Alignment

The mount has a re-alignment feature which allows you to replace any of the original alignment stars with a new star or celestial object. This can be useful in several situations: • If you are observing over a period of a few hours, you may notice that your original two alignment stars have drifted towards the west considerably. (Remember that stars are moving at a rate of 15° every hour). Aligning on a new star that is in the eastern part of the sky will improve your pointing accuracy, especially on objects in that part of the sky.

 In other words, this is a feature, not a bug. I also found the Hibernate function. We are making progress. It will be clear again tonight and Saturday. 

 

PREVIOUSLY ON NECESSARY FACTS

Documentation is Specification 

Backyard Astronomy 

Redshift: Six Years With Astronomy 

An Online Class in Astrophysics 

Against Dark Skies

We do not have the same perceptions with light that we do with sound. You can close your eyes. You cannot close your ears. So, we have laws against noise. We do need a rational theory of law to address noisy light. But not all light is pollution, any more than all noise is bad. After all, most people enjoy the sound of children playing and most so-called “light pollution” is equally benign.

Moreover, you can see a lot from the city if you know where to look. I live in the city of Austin, one mile from South Park Meadows, a major shopping center. From my backyard, I can show you the Andromeda Galaxy. On hobbyist discussion boards, I have shared my views of binary stars. This is an endeavor that many hobbyists pursue, seeking out stars that look like single points to the naked eye, but which a modest telescope will reveal to be two or even four. 

 

We backyard astronomers know the book, Turn Left at Orion by Guy Consolmagno, SJ, Ph.D. He had a doctorate from Harvard and taught at MIT, but never knew the sky the way an amateur does until a friend showed him the stunning yellow-blue double star known as Albireo at the head of The Swan (or the Foot of the Cross). His friend did that with a small portable telescope from within the glare of New York City in Fort Lee, New Jersey. Turn Left at Orion was written for the urban or suburban hobbyist. 

 

Some dark skies can be found in North America

One of our local leaders is a sun-watcher. With a special telescope costing four times more than a nice hobbyist instrument and ten times more than an entry-level telescope, he views our Sun, the closest star, and a very average star. Viewing in broad daylight, he never worries about light pollution.

 

Astronomers also complain about “constellations” of artificial satellites, clusters and strings launched by private companies for communications, natural resource monitoring, economic research, and disaster response. When disaster strikes, we all want our cellphones to bring the responders to our exact locations by GPS. That convenience comes with a cost. 

 

Not so dark in China; dark skies in North Korea.

Apart from the hobby, serious astronomy has been carried out for 50 to 70 years with radio telescopes, or “dishes.” First investigated by amateurs just before World War II, radio telescopes receive wavelengths that are not blocked by light pollution (or rain). Today, radio astronomy continues to be a pursuit for some amateurs. It is a spin-off of ham radio. 

 

Other leading edge research in astronomy is performed from orbiting platforms such as the Hubble and Hipparcos satellites. As enthusiasts of space exploration, the backyard astronomers do not complain about the consequences of building giant rockets to carry giant telescopes into orbit. 

 

Dark skies in central South America.

It is true that amateur astronomers collaborate with professionals. One way is by reviewing the data in computerized “warehouses” of numbers and images. We have more data than university professors can analyze. So, they turn to amateurs. Those hobbyists work from the comfort of their homes, consuming electrical power, and other resources, that also create light pollution.

 

Amateurs also build their own remote-controlled observatories and monitor the views on high-definition video screens. Those installations are hundreds of miles from their homes where the amateurs enjoy the benefits of civilization. 

 

Even deeper into the wilderness, some impassioned hobbyists travel to the darkest skies at state and national parks for their star parties. There, many of the instruments are custom-built, huge, complex telescopes, some of which need their own trailers to be hauled to the campsite. At those events, deep sky stargazers pursue “faint fuzzies” the galaxies and nebulas at the limits of viewing. For them, the planet Jupiter is light pollution. At a dark sky site, with no other competition, our solar system’s largest planet is bright enough to cast shadows. In the large “light buckets” built to gather the faintest glows from the farthest objects, the glare of Jupiter washes out the sky. So, one astronomer’s target is another astronomer’s light pollution. The same is true of the Moon. Some hobbyists do study it. It is not a dead world. But generally speaking most suburban hobbyists consider the Moon to be light pollution. 

 

I am not insensitive to the problem. I believe that a correct political analysis begins with considerations of property rights. A couple of years ago, I wanted to arrange the loan of a large hobby telescope to a co-worker who recently moved into a rural area. Sadly, he declined the offer because his neighbor had just installed a security light, a mercury-vapor spotlight that illuminated her land, his, and much else. If the light waves were sound waves, she would be blasting rock ‘n’ roll at 2:00 AM. That is a problem that is easy to understand and any number of local ordinances (if not common sense and common courtesy) would put a stop to it. 

 

We all want clear dark skies full of beautiful bright stars. Backyard astronomers also want telescopes, which are mass-production manufactured items, mostly from China. Even custom-made hobbyist telescopes two feet in diameter costing near $10,000 are built from precision glassware made in China. Backyard astronomers here do not mind if China's skies are polluted. 

Dark skies in central Africa, but not the Nile Valley.

 

I admit that it was at the Austin Astronomical Society's dark sky site 80 miles away from Austin that I first saw the Milky Way from horizon to horizon. It was worth the drive. There is no shortage of dark sky for anyone willing to make an effort, invest resources, and put up with some minor inconveniences. That being so, absent the amenities of civilization, daily life 80 miles from a Level One trauma center could be precarious should you break your arm or have a heart attack. Like telescopes, modern hospitals are another product of our industrial economy. What formal logic calls the law of the excluded middle is commonly expressed as, “You cannot have your cake and eat it, too.”

PREVIOUSLY ON NECESSARY FACTS

Seeing in the Dark: Your Front Row Seat to the Universe

Turn Left at Orion

Megacities

Anthropocene: A Bad Name for a Good Thing

Celestial Mechanics

I first got interested in celestial mechanics in 1978. I enrolled in three independent study classes at two schools, New Mexico State University, then at Lansing Community College (1981, 1982). In 1981, I met an astronomer from Michigan State University who encouraged me to get this book on algorithms for calculators. He wanted it for himself and I was working for a publisher. So I ordered two. I used the routines as outlines for some BASIC programs but never went much further with it. 

[An earlier version of this essay was posted to The Sky Searchers discussion board in the Astrophysics forum.] 

John Wiley and Sons.
(c) Aubrey Jones 1978

My wife and daughter bought me a telescope for my birthday in 2014. In the past six years, I have enjoyed going out in the backyard (often) and to star parties (a few times) and verifying for myself that the universe is pretty much as described in the books. But what’s next?

I am not facile with mechanical tasks. Things come apart a lot easier than they go back together. That can be useful for documenting physical systems, but it suggests that photography and spectroscopy are not likely to be rewarding as hobbies complementing observational astronomy.  
 

On the one hand, in order to pursue celestial mechanics you really need to love mathematics. As much as I enjoy it, I took Calculus-1 twice to get a C+. I learned integration (usually Calculus-2) by taking a computer programming class and coding up the Midpoint Rule, Simpson’s Rule, and the Trapezoid Rule. The advantage to me is that it is easier to erase a mistake than it is to drive to Home Depot to buy another part (which I have to do to finish work on the backyard gate). 

McCuskey, Addison-Wesley, 1963

In the 18th and early 19th centuries, orbit plotting was the focus of astronomy. Following Sir Isaac Newton’s Principia, and the parallel work of Gottfried Wilhelm Leibniz, Pierre-Simon Laplace developed what we recognize today as the calculus of celestial mechanics. It allowed astronomers to establish the orbits of the planets and their newly discovered moons and the two new planets, Uranus and Neptune, and their moons. It also allowed astronomers to determine the physical arrangements of binary stars. With the advent of photography and spectroscopy, orbit plotting fell out of favor with researchers as those tools revealed deep and starling new truths. However, even as radio astronomy came to the fore in the 1950s, celestial mechanics regained some importance with the space age. 

 

But if you are not the person launching a satellite to Saturn, why grind through transcendental equations? My reply is the same as for any amateur pursuit, any hobby, or sport: You do it for yourself because it is at once rewarding and edifying. And unlike most other hobbies, astronomy is a study where amateurs and professionals collaborate. 

 

How fast does the Moon go around the Earth?

How fast does the Sun go around the Earth?

How fast do the stars go around the Earth?

And when will that comet come back?

 

If you have lived any arbitrarily long time, you know that our easy estimates – the Moon travelling through 360 degrees in 28 days; the Sun circling the Earth 360 days each year (plus 5 days for a long holiday "off the books"); the fixed stars moving westward one degree per night through the year -- have errors that accumulate. Can I make more accurate predictions?

 

Not only has the hard mathematics been done already, reducing the problems to the application of formulae, but I now have a computer and a spreadsheet. All I have to do is take the measurements and reduce the data.

 

(More later.)

 

PREVIOUSLY ON NECESSARY FACTS

Newton and Leibniz

Astrophotography is a Lot like Love 

Measuring Your Universe: Alan Hirshfeld’s Activity and Laboratory Manual

In Support of the Entry-Level Telescope 

John Kemeny Knew: We Shall Have Computed 

 

 

Astrophotography: What He Meant by What He Said

Having retired from the Texas State Guard and leaving numismatics to take second place, I have been giving more attention to astronomy. I participate in The Sky Searchers discussion forum for amateur astronomy. The moderators launched this after their first site, The International Astronomy Forum, was overwhelmed by malicious software seeking user information (“malware bots”). After a few posts in the original forum five years ago, I left it and only returned to the new forum in November. 

One aspect of a hobby is that the learning is often informal. Even though astronomy is taught in college, how it is practiced by those who earn their living in other areas brings a lot of jargon. Numismatics is like that, also. I just earned my 25-year pin from the ANA, but also just figured out that on discussion boards, LCS stands for “local coin store.” 

Earlier this week, on the Sky Searchers, I read a post that sent me on a five-hour homework assignment  It started here:

https://www.theskysearchers.com/viewtopic.php?f=66&t=5650

Contact: jmt92130

Soul Nebula - bicolor with RGB Stars

Post  by jmt92130 » Sun Dec 22, 2019 6:43 pm

Thumbnail image

Image title: IC 1848 / Sh2-199 in Cassiopeia

Link to Image: http://www.jthommes.com/Astro/IC1848--SH2-199.htm

Here is a bicolor narrow band image of the [sic] The "Soul Nebula" (IC 1848, Sh2-199). The full IC 1848 (cluster plus nebulosity) seems to be a widely studied star forming region - the Simbad database turns up many young stellar objects and candidate YSO's. There are three Collinder clusters, several LBNs, and several Sharpless objects in this image field. 

The narrow band integrated images (Ha and OIII) were converted to starless and combined with pixel-math. Stars were processed with RGB data and later combined with the narrow band result using pixel math. 

Image and details are accessed from the link below. The annotated image can be linked from the main image page but I have also provided a link below for convenience. The full size image (2.4 arcsec/pix) can be accessed from the image webpage links

Decryption by Michael E. Marotta

The SkySearchers username mikemarotta

(jmt92130’s original comments are in Helvetica. Explanations are in Georgia. Citations follow quotations.)

Jmt92130 wrote: The Soul Nebula

The Heart and Soul nebulae are seen in this infrared mosaic from NASA's Wide-field Infrared Survey Explorer, or WISE. The image covers an area of the sky over ten times as wide as the full moon and eight times as high (5.5 x 3.9 degrees) in the constellation Cassiopeia.

Located about 6,000 light-years from Earth, the Heart and Soul nebulae form a vast star-forming complex that makes up part of the Perseus spiral arm of our Milky Way galaxy. The nebula to the right is the Heart, designated IC 1805 and named after its resemblance to a human heart. To the left is the Soul nebula, also known as the Embryo nebula, IC 1848 or W5. The Perseus arm lies further from the center of the Milky Way than the arm that contains our sun. The Heart and Soul nebulae stretch out nearly 580 light-years across, covering a small portion of the diameter of the Milky Way, which is roughly 100,000 light-years across. 

The two nebulae are both massive star-making factories, marked by giant bubbles that were blown into surrounding dust by radiation and winds from the stars. WISE's infrared vision allows it to see into the cooler and dustier crevices of clouds like these, where gas and dust are just beginning to collect into new stars. These stars are less than a few million of years old -- youngsters in comparison to stars like the sun, which is nearly 5 billion years old.

Also visible near the bottom of this image are two galaxies, Maffei 1 and Maffei 2. Both galaxies contain billions of stars and, at about 10 million light-years away, are well outside our Milky Way yet relatively close compared to most galaxies. Maffei 1 is the bluish elliptical object and Maffei 2 is the spiral galaxy.

All four infrared detectors aboard WISE were used to make this image. Color is representational: blue and cyan represent infrared light at wavelengths of 3.4 and 4.6 microns, which is dominated by light from stars. Green and red represent light at 12 and 22 microns, which is mostly light from warm dust.

https://www.nasa.gov/mission_pages/WISE/multimedia/wiseimage20100524.html

Westerhout 5 (Sharpless 2-199, LBN 667, Soul Nebula) is an emission nebula located in Cassiopeia. Several small open clusters are embedded in the nebula: CR 34, 632, and 634[citation needed] (in the head) and IC 1848 (in the body).  -- https://en.wikipedia.org/wiki/Westerhout_5

jmt92130 wrote: (IC 1848, Sh2-199).

IC — Index Catalogue

IC I — Index Catalogue I

IC II — Index Catalogue II

The first major update to the NGC is the Index Catalogue of Nebulae and Clusters of Stars (abbreviated as IC), published in two parts by Dreyer in 1895 (IC I,[5] containing 1,520 objects) and 1908 (IC II,[6] containing 3,866 objects). It serves as a supplement to the NGC, and contains an additional 5,386 objects, collectively known as the IC objects. It summarizes the discoveries of galaxies, clusters and nebulae between 1888 and 1907, most of them made possible by photography. A list of corrections to the IC was published in 1912.[7]

https://en.wikipedia.org/wiki/New_General_Catalogue#Index_Catalogue

(My turn to apologize: I already knew that NGC is the New General Catalog, a 19th century compilation of sky objects.). 

The Sharpless catalog is a list of 313 H II regions (emission nebulae) intended to be comprehensive north of declination −27°. (It does include some nebulae south of that declination as well.) The first edition was published in 1953 with 142 objects (Sh1), and the second and final version was published by US astronomer Stewart Sharpless in 1959 with 312 objects. Sharpless also includes some planetary nebulae and supernova remnants, in addition to H II regions.[1]

https://en.wikipedia.org/wiki/Sharpless_catalog

jmt92130 wrote: Simbad database

The SIMBAD astronomical database provides basic data, cross-identifications, bibliography and measurements for astronomical objects outside the solar system.

SIMBAD can be queried by object name, coordinates and various criteria. Lists of objects and scripts can be submitted.

Links to some other on-line services are also provided.

Statistics

Simbad contains on 2019.12.28

10,905,523      objects

35,587,649      identifiers

365,712           bibliographic references

20,522,365      citations of objects in papers

If the Simbad database was helpful for your research work,

the following acknowledgment would be appreciated:

This research has made use of the SIMBAD database,

operated at CDS, Strasbourg, France 

2000,A&AS,143,9 , "The SIMBAD astronomical database", Wenger et al.

http://simbad.u-strasbg.fr/simbad/

jmt92130 wrote: Collinder clusters

In astronomy, the Collinder catalog is a catalog of 471 open clusters by Swedish astronomer Per Collinder. It was published in 1931 as an appendix to Collinder's paper On structural properties of open galactic clusters and their spatial distribution.[1] Catalog objects are denoted by Collinder, e.g. "Collinder 399". Dated prefixes include as Col + catalog number, or Cr + catalog number, e.g. "Cr 399".[2]

https://en.wikipedia.org/wiki/Collinder_catalog

The Collinder catalog was published originally in the Annals of the Observatory of Lund.

Jmt92130 wrote: several LBNs,

Lynds' Catalogue of Bright Nebulae is an astronomical catalogue of bright nebulae.

Objects listed in the catalogue are numbered with the prefix LBN (not to be confused with LDN, or Lynds' Catalogue of Dark Nebulae), though, many entries also have other designations, for example, LBN 974, the Orion Nebula is also known as M42 and NGC 1976.

It was originally compiled in the 1960s by Beverly Lynds.[1] Objects in the catalogue include (among other things) the coordinates of nebulae, brightness from 1-6 (with 1 being the brightness), colour and size and cross-references to other astronomical catalogues if listed elsewhere.[2]

https://en.wikipedia.org/wiki/Lynds%27_Catalogue_of_Bright_Nebulae

The Lynds' Catalog of Bright Nebulae lists the coordinates of the center of the cloud, the dimensions of the nebulae as measured on the photograph on which it appeared at its brightest, the area of nebulosity in square degrees, color as compared between the blue and red Palomar plates, a brightness index on a scale from 1 to 6, an identification number that indicates the complexity of the nebulosity, and a cross reference to NGC (Cat. <VII.1>), Index Catalogue (IC), Sharpless (1959) Catalogue of HII Regions (Cat. <VII/20>), Cederblad (1956) Catalogue of Diffuse Galactic Nebulae, and Dorschner and Gurtler (1963).

https://heasarc.gsfc.nasa.gov/W3Browse/nebula-catalog/lbn.html

jmt92130 wrote: Sharpless objects

See above Sharpless Catalog.

jmt92130 wrote: The narrow band integrated images (Ha and OIII)

[MEM -- O III is an astronomical term for what chemists and others call O++ doubly ionized oxygen. (It was originally thought to be evidence of a new element, dubbed “nebulium.”)]

Viewed in a narrow slice of the spectrum centered in the ruby-red H-alpha line, the Sun throbs with activity.

H-alpha filters work by rejecting all but the narrow sliver of H-alpha light. 

https://www.skyandtelescope.com/observing/guide-to-observing-the-sun-in-h-alpha092321050923/

H-alpha (Hα) is a specific deep-red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air; it occurs when a hydrogen electron falls from its third to second lowest energy level. H-alpha light is the brightest hydrogen line in the visible spectral range. It is important to astronomers as it is emitted by many emission nebulae and can be used to observe features in the Sun's atmosphere, including solar prominences and the chromosphere.

https://en.wikipedia.org/wiki/H-alpha

jmt92130 wrote: pixel-math. 

PixInsight's PixelMath performs a series of pixel-level arithmetic and logical operations between images.

https://www.pixinsight.com/doc/legacy/LE/22_pixel_math/pixel_math/pixel_math.html

Pleiades Astrophoto is a software development company based in Spain, Europe. We work to provide cutting edge image processing and analysis tools for a broad range of technical imaging applications. We design and implement novel paradigms and innovative methodologies.

PixInsight is our main development project.

https://www.pixinsight.com/about/index.html

jmt92130 wrote: … bicolor… 

Modified Bicolor Technique for combining Ha and OIII images

All Images and Content  Copyright Steve Cannistra unless otherwise noted.

Brief overview:  Ha is used for the R channel, and OIII is used for the B channel.  The synthetic green channel is created by multiplying the OIII layer with the Ha layer.  Construction of the color composite is done using the layer method in Photoshop CS and should be followed exactly as described for best results.  http://www.starrywonders.com/bicolortechniquenew.html

jmt92130 wrote: RGB data 

[MEM - Red-Green-Blue Image processing in both astrophotography and Earth-based geographic information systems (GIS) rely on a well-developed theory and technology based in the physiology of sight and the physics of light. (I completed my MA in social science with two graduate classes in geographic information systems, then worked the following summer as a contractor, writing laboratory learning instructions.) Another system common in our office printers is CMYK: Cyan Magenta Yellow Black. Recall that the primary (“rainbow”) colors are Red, Orange, Yellow, Green, Blue, and Violet. The primary pigments (paints, crayons) are red, yellow, and blue. Pigments reflect one color and absorb all others. We get green pigment by mixing yellow and blue. In color processing from light in RGB, yellow comes from mixing 100% Red with 100% Green.]

jmt92130 wrote: Image and details are accessed from the link below. 

Following that link led to this summary:

Scope: FSQ-106N at f/5, Location: DAA Observatory, Shelter Valley, CA, 31 July and 7 August 2019,  Camera: Atik 383L (Astronomik Gen 2  Ha OIII LRGB Filters)

Exposure: 12 x 8 min  (1x1 bin)  UV/IR block Lum filter, 24 x 10 min (1x1 bin) Ha filter, 18 x 10 min (2x2 bin) OIII  filter, 8 x 4 min (2x2 bin) each RGB filters.

Processing: Data Collection -  Sequence Generator Pro (as FITs).  Subframe calibration and registration - PixInsight. Subframe integration (Median combine -  Winsorized Sigma Clipping) - PixInsight.  Non-linear stretching, normalization and gradient removal - PixInsight.  Generation of starless nebulosity images - starnet++.  Starless color mapping and LRGB stars color mapping - PixInsight. Stars and Starless combine - PixInsight. Final finishing  - Photoshop.  RGB calibration - eXcalibrator. Annotation - PixInsight, Aladin (Simbad and NED), and PhotoShop. This image is a modified HOO narrow band mapping with RGB stars.  Images processed at 3354 x 2529 resolution. Final Image size is approximately  3000x2250.

jmt92130 wrote:  Scope: FSQ-106N at f/5, 

TAKAHASHI FSQ-106EDX4 F/5 PETZVAL REFRACTING OTA TELESCOPE

Takahashi FSQ-106EDX4 f/5 Petzval Refracting OTA Telescope

ITEM #TK-TQE10630

88mm medium format sized image circle

ED Glass Elements

178mm of back focus 

4-Inch heavy duty focuser with anti-torquing draw tube

Airline Portable smaller than 17-inches with dew shield retracted

Multiple focal reducer options available that can make the scope as fast as f/3

Tele-extender available that makes the focal length 850mm

https://optcorp.com/products/takahashi-fsq-106edx4-f-5-petzval-refracting-ota-telescope

jmt92130 wrote: Location: DAA Observatory, Shelter Valley, CA,

(Desert Astronomy Association - DAA)

Desert Astronomy Association Observatory Campus

March 1, 2019      

DAA is a small association of astronomers who have established an astronomy campus in the East San Diego County high desert area. DAA location is in a small privately held community property in the middle of the Anza Borrego Desert State Park. The park is the largest in California at 585,930 acres and listed in the top ten state parks in the United States (InterExchange.org). The skies are reasonably dark (Bortle 3) at the DAA location. A Dark Sky community (Borrego Springs, Bortle 4) is located about 15 miles away and is also surrounded by the state park.

http://www.jthommes.com/Astro/Observatory.htm 

https://www.cloudynights.com/topic/652570-daa-observatory-campus/

jmt92130 wrote: Camera: Atik 383L (Astronomik Gen 2… 

The Atik 383L + features the Kodak KAF-8300 CCD with a huge number of good-sized pixels. This sensor has redefined mid-range astro-imaging, making multi-megapixel cooled cameras much more accessible. Atik prides itself on providing cameras offering the very highest deep sky imaging quality at a reasonable cost.

https://www.atik-cameras.com/product/atik-383l-plus/

CCD is a charge-coupled device, a semi-conductor chip.

https://en.wikipedia.org/wiki/Charge-coupled_device 

jmt92130 wrote: LRGB Filters

Luminance, Red, Green and Blue filters.

[MEM - Luminance filters just block all white light unselectively. The common “moon filter” is an example of that. We use them on our telescopes to reduce the brightness of a full moon.] 

jmt92130 wrote:  Winsorized Sigma Clipping

Winsorizing or winsorization is the transformation of statistics by limiting extreme values in the statistical data to reduce the effect of possibly spurious outliers. It is named after the engineer-turned-biostatistician Charles P. Winsor (1895–1951). The effect is the same as clipping in signal processing.

https://en.wikipedia.org/wiki/Winsorizing

Suppose you have a set of data. Compute its median m and its standard deviation sigma. Keep only the data that falls in the range (m-a*sigma,m+a*sigma) for some value of a, and discard everything else. This is one iteration of sigma clipping. Continue to iterate a predetermined number of times, and/or stop when the relative reduction in the value of sigma is small.

Sigma clipping is geared toward removing outliers, to allow for a more robust (i.e. resistant to outliers) estimation of, say, the mean of the distribution. So it's applicable to data where you expect to find outliers.

https://stackoverflow.com/questions/45666970/what-is-sigma-clipping-how-do-you-know-when-to-apply-it

jmt92130 wrote:  non-linear stretching, normalization and gradient removal

Non linear stretching is the work horse for producing "pretty pictures" with astrophotography.  This process completely destroys the data for any scientific use and is frowned upon by some purists.  However, this is the only way to simultaneously show the faint and bright detail. Here's how to do it.  http://bf-astro.com/non-linearCurves.htm

[MEM - Normalization and gradient removal are manipulations that take out extreme data, such as objects that are much brighter than others nearby.] 

jmt92130 wrote: HOO narrow band

HOO is really H-sub infinity.
H∞ techniques have the advantage over classical control techniques in that they are readily applicable to problems involving multivariate systems with cross-coupling between channels; disadvantages of H∞ techniques include the level of mathematical understanding needed to apply them successfully and the need for a reasonably good model of the system to be controlled. -- https://en.wikipedia.org/wiki/H-infinity_methods_in_control_theory

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