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General Astronomy >> General Observing and Astronomy

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drollere
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Re: unlearning the constellations new [Re: Jon Isaacs]
      #5479146 - 10/19/12 05:07 PM

Quote:

We all enjoy the sky in a different way... I very much enjoy just wandering around and seeing what I can see, figuring out what it is, learning something about it... I don't use GOTO, I view the constellations as part of the road map, sign posts to help me find my way from one part of the sky to another.

I am a big believer in using a telescope as an instrument of discovery rather than as tool to go down a list of objects... For me, it's not the science as much as it is the aesthetics, I just enjoy looking through a telescope/binoculars/naked eye at the night sky... It's just neat being out there under the night sky.



there is a whole physical, sensual, spiritual, emotional and esthetic dimension to astronomy, certainly. it is neat, but i wasn't addressing it specifically.

there are many ways to see, study, appreciate, enjoy the night sky with the use of optical instruments. whatever anyone wants to do, however they want to do it, is fine with me. (as if what i thought had the slightest importance to how or why they want to do what they do.)

i *am* saying that there are walls around the common approach. once you look for them, they are palpable. the novice asks, "what is the best magnification?" -- the advice is: why, the magnification that frames the object. start with the object, which can't be more than a few arcminutes wide, and put a frame around it. cut out everything else, ignore it, assume it doesn't matter. then go on to the next object, put a frame around that, and so on.

what's a good book about astronomy? well there's this book here, that gives you a *list* of things to look at, or a chapter on each of 100 objects, all separately described. ... and how many other books are just like that one? isn't there fundamentally a routine and limitation in the *information resources* available to us? aren't we habituated to look at the sky in a certain way by how we find things to look at?

the point made above about light pollution is right on. glare does nudge us to look for bright, discrete, identifiable targets, because the milky way is blotted from view. but so too do books and atlases that never indicate there is anything else to see, that show the milky way as a smear of monotone. it's remarkable that one of the most intimate and detailed descriptions of the whole milky way available anywhere is in ... ptolemy's almagest, Book VIII.

i greatly admire jon's approach to observing, and i endorse it as incredibly pleasurable. i once started from beta cygni and worked my way by random slews up through gamma and out to delta, and still remember it as something like a boat cruise up an enchanted river. i discovered many things that i could not later identify with a catalog. i was the tourist who just puts the tour guide in the backpack and wanders up an alley.

but also like the tourist who wanders without a map. it's not just that we habitually look in a certain way, and there is another way to look: it's that we don't have the resources to make any other way of looking informative. fun and stimulating, yes, but enriching, insightful, illuminating, educational? if we had signposts as we wandered, the whole experience would be more memorable. we could actually see and comprehend our place in the galaxy.

i liked the suggestion made about a software program focused on these topics. where can i get it? the software > Where is M13? < is a rudimentary version of what i had in mind, but it does not link the objects to the visible milky way, but to a galaxy schematic.


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bumm
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Re: unlearning the constellations new [Re: drollere]
      #5479416 - 10/19/12 08:10 PM

As one who loves the constellations, I've sort of steered clear of this thread too... As near as I can tell, the suggestion here is that we should be viewing and understanding the universe as a whole, and not just objects as found on an artificially constructed map of the sky. That's fine... but I think most all of us with any curiosity proceed to assemble the pieces and gain an understanding of the universe as we enjoy observing it's fragments. While I'm sure you aren't suggesting that the constellations should be left behind as an obsolete artifact of times past, they also are a part of the big picture. While they are only chance patterns of moving stars seen from our particular location and time, they're a part of human history and experience, from the eighteen thousand year old picture of the Pleiades on the cave wall at Lascaux, to the most recent computerized star charts. Most every night, I go out and name all the stars I can, just so I never forget...
Marty


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Tony Flanders
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Re: unlearning the constellations new [Re: Dennis_S253]
      #5479431 - 10/19/12 08:16 PM

Quote:

I knew I should stay away from this. Starting with the title, "unlearning the constellations".




The title is probably unnecessarily combative. I think "Beyond the Constellations" would be more accurate.

For me, the greatest glory of astronomy is that there are so many different ways to approach it. There had better be! It is, after all, the study of the universe -- literally, everything that is, has been, or ever will be. I find the aesthetic approach, the historical approach, the study of individual objects and stars, and the study of how they fit together, all equally interesting.


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FirstSight
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Re: unlearning the constellations new [Re: Tony Flanders]
      #5479475 - 10/19/12 08:47 PM

For those among us who usually have to put up with mag 5 or lesser skies, a trip to a true mag 7+ gray or black site on a moonless night, especially when the summer Milky Way is ascendant, IS of itself a FORCED lesson in "unlearning" the constellations. It can take awhile before you begin to recognize familiar constellation landmarks because they're lost amid the unfamiliarly dense swarm of visible stars and steamy knots of the indistinct glow of millions of stars too faint to see individually, and the winding dark nebular rivers running in-between the clouds of stars.

Edited by FirstSight (10/19/12 08:52 PM)


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auriga
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Re: unlearning the constellations new [Re: drollere]
      #5479536 - 10/19/12 09:34 PM

Bruce,
A number of points:

1. Your gifs are great and show a lot about the sky that other representations don't show. I agree with you that these alternative representations of the sky are valuable. Thanks for posting them.

2. You raise very important questions. As far as I can tell, the Herschel 400 I and II, while no doubt valuable and worthwhile, convey little understanding of the structure of our galaxy as a whole. Observing lists in general can have this limitation. So I agree with this part of your thesis as well.

3. The pinhole view is narrow in the sense that one is observing only a small portion of our galaxy. But with my 13 Ethos ( I don't have the 17) in my 16"f/4 Dob the view is perceptually wide, 100 degrees wide. Al Nagler is right about the "grandeur factor." The emotional and perceptual sense of the breadth and vastness of our universe is conveyed in part by these huge visual fields even though in terms of absolute distances they are very narrow indeed.

4. There are some guides in the area of galactic structure. Prime among them, and going far beyond Craig Crossen's Binocular Astronomy, is his subsequent book, with Gerald Rhemann, "Sky Vistas" (published by Springer). He devotes great attention to the structure of our galaxy. Another guide is Bill Tschumy's "Where is M13?" I am sure you are familiar with these but my point is that a huge amount can be learned about the structure and content of our galaxy by careful study of these sources, which you have doubtless already done.

6. If your thesis is that we need to spent time scanning the Milky Way with binoculars, looking for star clouds, dust lanes, dark nebulae, and OB associations, in order to get an understanding of and appreciation for our own beautiful galaxy, I agree entirely.

7. Where I part company with your thesis is as follows: When I look at M17 I enjoy it as an object in itself, but I try also to be aware of where it lies in our galaxy. I value diagrams like "Where is M13" that show it visually. And I devote special attention to objects that are far out toward the Perseus arm, such as the Double Cluster and one or two more distant objects in that direction. I also try to look at objects near the galactic center, such as NGC 6522 and 6528, in Baade's Window, with the realization of where they are; similarly for objects in our Orion Arm. My point here is that viewing individual objects is not exclusive of understanding the galactic structure, and that binocular study, while essential for this purpose, is not the only contributor to this understanding.

Knowing where in our galaxy an object is, adds a great deal to the pleasure of observing it and to my understanding of the object and our galaxy. To know that M54, while not outstanding visually, is probably the core of a now dispersed galaxy, enriches the visual experience.

I am also very interested in viewing the sky in terms of the absolute brightness of the stars in it. So, I always like to take a look at Zeta 2 in Scorpius, and 6231 is itself one of my favorite objects. And Rho in Cassiopeia, and P Cygni, and Wesen and Aludra in Canis Major.

As a related issue, I think the OB associations, especially in Perseus and Scorpius, are much neglected by observers. Perhaps because they are too easy to find and so don't confer much prestige on the observer?

Bill Meyers


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derangedhermit
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Re: unlearning the constellations new [Re: drollere]
      #5479684 - 10/19/12 11:11 PM

Quote:

[...]a large part of that has to do with the pinhole mentality[...]

[...]put that 17mm 100 $800 tele vue ethos in your 16" /4 dob[...]

[...]we piece together glimses of these pinhole samples of the sky as isolated features with nonsense pidgin arabic or cartoon character names, and call it "astronomy" with the absurdity of someone who has a pet name for every piece in a 100 or 1000 piece jigsaw puzzle but has never put the puzzle together to see what it represents.[...]

[...]constellations only cement the delusion[...]

[...]the problem seems so big that it's hard to know where or how to begin.[...]

[...]perhaps we look at far away objects in isolated and tiny fields of view because ... it is just so much easier to do.




Quote:

there are two ways to misinterpret a post, and you've done both.





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Man in a Tub
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Re: unlearning the constellations new [Re: drollere]
      #5479731 - 10/19/12 11:45 PM

Quote:

i liked the suggestion made about a software program focused on these topics. where can i get it? the software > Where is M13? < is a rudimentary version of what i had in mind, but it does not link the objects to the visible milky way, but to a galaxy schematic.




Try this:

http://www.haydenplanetarium.org/universe/about

It's free. I've had just about every updated version since I learned of it while reading Natural History magazine.


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GlennLeDrew
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Re: unlearning the constellations new [Re: derangedhermit]
      #5479773 - 10/20/12 12:29 AM

The unfortunate use of one word--"unlearning"--seems to have diverted some readers from the true spirit of Bruce's thesis. As Tony has suggested, a title more along the lines of "Beyond the Constellations" would have more accurately conveyed Bruce's intentions.

As I read it, and practice myself, the 'pinhole' view is not unappreciated, and certainly not denigrated. Indeed, it's vitally necessary in order to discern any kind of detail for the smaller and more distant objects. The point is that most backyard observers tend to focus overly much on an object in isolation, where a broader perspective would engender even greater appreciation.

The kind of study required to build a fuller picture need not occur in the field, where precious eyepiece time can be more fruitfully allocated to the detailed picture. We now have many resources at our disposal:
- Books, such as Crossen's Binocular Astronomy, Crossen and Reihman's [sic] Sky Vistas, Couper and Henbest's Guide to the Galaxy, to name a few.
- Software, like Hayden Planetarium's Partiview (highly recommended!). [in Edit: Todd beat me to it]
- Atlases, like The Cambridge Photographic Sky Atlas.
- Online images, milky way mosaics (especially), etc.

Cloudy nights (yes ) can be put to good use doing the 'deskwork'.

In my own case, I learned the 2-D geography of the sky very rapidly in the early- to mid-eighties by taking tripod-mounted photos on high speed film, of no more than 60 seconds' duration, through 28mm and 50mm lenses. With prints in hand, I would annotate all the DSOs captured (and there were lots!) by comparing with the venerable Skalnate Pleso atlas.

My journey on the discovery of our home Galaxy began in earnest when I obtained the book, "Guide to the Galaxy" in 1992-3. It included plan view charts which mapped out the Galaxy as then known, with a good amount of detail in the Sagittarius, Cygnus-Orion and Perseus arms.

Soon afterward Binocular Astronomy further cemented some details.

The next big leap came with my discovery in 2003 of Partiview, a 3-D software package available as a free download. The interface is not exactly intuitive, being seemingly designed more for engineers. Indeed, Partiview is really a generic particle visualization tool, adapted for astronomers simply building suitable databases. Get through the tutorial and you'll at least be able to fly about through space and really get a feel for the arrangement of stars, clusters (open and globular), associations, nebulae (including planetaries), and even pulsars. I love this stuff!

And do I learn it just for me? Nope. At a star party I typically regale those waiting for a telescopic view with a story. In a couple or few minutes I might cover:
- The 475 l-y distant Upper Scorpius OB association, comprising the near-its-end supergiant Antares and other stars of the heart and claws.
- The runaway star zeta Oph, which departed Upper Sco 1 millin years ago after a SN explosion, and us currently lighting up a 10 degree wide, dim nebula as it traverses the Ser-Oph rift of dark clouds, among the nearest to us. The other remnant from the SN blast is a pulsar (neutron star), flying rather faster and so is located well away in Aquila.
- The great difference in the distance to dark clouds toward the central milky way: The Ser-Oph rift of dark clouds, as near as ~400 l-y, which diverge northward from the band of the milky way and extend well up into Ophiuchus; The ~5,000 l-y distant Great Rift lying along the galactic equator, which resides mainly along the outer edge of the Sagittarius spiral arm and inside of which the Lagoon nebula resides.
- The recession into the distance of the nearby Rift clouds which lie essentially along the inner edge of our own local spiral arm, starting at Ser-Oph at 400-500 l-y, terminating in Cygnus some 3,000 l-y away.
- The importance of these dark clouds, because they contain from thousands to millions of Sun's worth of molecular gas, from which future stars, solar systems and stargazers will be made.


And more besides, time and interest permitting.


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Astrodj
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Re: unlearning the constellations new [Re: Man in a Tub]
      #5479833 - 10/20/12 01:50 AM

"Try this:

http://www.haydenplanetarium.org/universe/about

It's free. I've had just about every updated version since I learned of it while reading Natural History magazine."


This is terrific! Looks like someone imagined it way before I did, and did something about it too!

Thanks.


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Man in a Tub
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Re: unlearning the constellations new [Re: Astrodj]
      #5479873 - 10/20/12 03:04 AM

Hope you like it as you learn the GUI. When you travel away from the solar system in the Milkway Atlas of Digital Universe, do turn off the constellation lines. Otherwise, your computer screen will look like an interstellar game of pick-up sticks.



Edited by Man in a Tub (10/20/12 04:02 AM)


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auriga
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Re: unlearning the constellations new [Re: GlennLeDrew]
      #5480351 - 10/20/12 12:58 PM

I have Cooper and Henbest. Lots of good information in a remarkably ugly book.
Bill Meyers


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drollere
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Re: unlearning the constellations new [Re: auriga]
      #5480405 - 10/20/12 01:27 PM

here's another way to approach the issue.

here's a basic test: take the test, and see how you do. note that these are all "landscape" questions -- none have to do with astrophysics, cosmology, or any other arcane expertise. these are all questions of the type -- "you're in yosemite valley, where is half dome?"

if you don't do so well, then perhaps you should give my post a second thought?

1. A novice asks you, "Where is the center of our galaxy?" Where do you point, and how far away do you say it is?

2. A novice asks you, "As the Sun revolves around the center of the galaxy, in what direction is it headed?" Where in the sky (or at which star) do you point?

3. There are 20 "bright" stars (v.mag. > 2.5) within twenty parsecs of the sun -- our near companions in our galactic journey. Name five.

4. How many other stars, besides these 20 bright stars, are within 20 parsecs of the sun?

5. The sun is most closely associated with a specific spiral arm of the galaxy. Which one?

6. This spirial arm is visible as a large part of the Milky Way. From our viewpoint on Earth, where does this spiral arm appear to start, and where does it end?

7. What is the closest galactic star cluster to Earth?

8. Where is the closest region to Earth where stars are actively being formed?

9. The Milky Way appears to divide into two bands in what part of the Milky Way? What causes this separation?

10. What is the farthest part of the Milky Way that we can see from Earth? Where is it, and how far away is it?


i'll wait for some answers (or individual tallies of the number of questions that can be answered), before i post answers of my own.

edit: wording of two questions clarified.

Edited by drollere (10/20/12 03:55 PM)


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drollere
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Re: unlearning the constellations new [Re: Tony Flanders]
      #5480529 - 10/20/12 02:48 PM

Quote:

The title is probably unnecessarily combative. I think "Beyond the Constellations" would be more accurate.

For me, the greatest glory of astronomy is that there are so many different ways to approach it. There had better be! It is, after all, the study of the universe -- literally, everything that is, has been, or ever will be. I find the aesthetic approach, the historical approach, the study of individual objects and stars, and the study of how they fit together, all equally interesting.



well, from my side, "beyond the constellations" has too specific a spatial or too vague a metaphorical thrust. it is also, as a rubric, hackneyed to the point of parody ("beyond the valley of the dolls").

the constellations are, after all, the anchor for a traditional way of talking about and observing the sky. "showcase doubles in cygnus," "deep sky objects in leo" -- these are just ways to dole out a ration of tiny objects in tiny corners of the sky, an approach that is encouraged by our books and the nature of our equipment. and perhaps by the fact that few of our peers point out that "hey! there's another way!"

and, since you mention it, i'm not saying we need to burn books that refer to ancient or striking asterisms. i'm saying they are fundamentally not an informative or insightful way to organize our "mental map" of the sky. the constellations were created to mark seasons, anchor myths, assert the superstitions of astrology, flatter patrons and fill unnamed territory in star atlases. we have more justification to divide the study of geology by state boundaries or to organize the periodic table with alchemy.

i have to say, purely as my own personal idiosyncracy of idiopathic solipsism and errancy, that i'm flabbergasted by the fact that, because i advocate what seems to me to be a fairly unpopular or unexplored way to think about astronomy, everyone has to affirm that there are many other ways to do astronomy and that they are all equally valid and fun and interesting.


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jrbarnett
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Re: unlearning the constellations new [Re: GlennLeDrew]
      #5480536 - 10/20/12 02:50 PM

Happy birthday, Glenn.

- Jim


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drollere
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Re: unlearning the constellations new [Re: drollere]
      #5480594 - 10/20/12 03:29 PM

brief thanks and comments to the substantive posts ...

bumm ... i agree completely that the curious will get where they are going. my regret is that there aren't more references able to assist the individually curious. as i said, wandering is fun, but a map really helps. and glenn's post suggests how much curiosity is necessary to boot up an understanding of the big picture.

firstsight ... yes, i think light pollution has a lot to do with it, as you say the experience of a truly dark sky is awe inspiringly unfamiliar. and the more i think about it, the more that seems to be a fundamental objection. dispiriting indeed, but maybe realistic, to realize how much modern infrastructure blocks our view of fundamental things.

auriga ... wow, well just to the point where we "diverge" -- actually i was suggesting that we could use specific stars or objects as markers to larger features, in the way you and glenn demonstrate. which features, which markers? i suggested "unlearning" the constellations as preliminary to freeing up individual stars for other purposes. do we really need the *constellation* scorpius in order to outline the OB association in that part of the sky?

... yes, the view through a 100 ethos is flattering and entertaining. so too is the marketing behind it. chasing messier objects and knocking down herschel or double star lists, all great and rewarding challenges (i've done it myself). articles that focus on constellations or cosmology -- entertaining, popular, widely used. but look how all those things point our attention and expectation in a specific direction. it amounts to an established culture.

glenn ... you're the man. i've noticed many others with similar preferences for big sky and wander watching, but you and jon are the most frequent and genial advocates.

todd ... thank you for the hayden planetarium pointer! i tried downloading the software in the past but it didn't work for me for some forgotten reason. i'll try it again.

bill ... the couper/henbest book looks very interesting -- i just ordered it, ugly or otherwise.


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auriga
Pooh-Bah


Reged: 03/02/06

Re: unlearning the constellations new [Re: drollere]
      #5480605 - 10/20/12 03:39 PM

Quote:

here's another way to approach the issue.

it's a simple test: take the test,

[but not simple to give the correct answers. And may be contaminated by a correlation to verbal I.Q.]

and see how you do. note that these are all "landscape" questions -- none have to do with astrophysics, cosmology, or any other arcane expertise. these are all questions of the type -- "you're in yosemite valley, where is half dome?"

[Okay, I'll bite.]

if you don't do so well, then perhaps you should give my post a second thought.

[Even if we do well your post deserves careful thought.]

1. A novice asks you, "where is the center of our galaxy?" Where do you point, and how far away do you say it is?

[Unfortunately novices don't ask questions like these. If they do, say " "Hurry, you'll be late for your class at Cal Tech!"]

[Sagittarius, 30,000 ly.]

2. A novice asks you, "in what direction is our rotation around the center of the galaxy taking us?" Where (or at which star) do you point?

[Deneb and Gamma Cygni are rotating away from us].

3. There are 20 bright stars (v.mag. > 2.5) within twenty parsecs of the sun -- our near companions in our galactic journey. Name five.

[Alpha Centauri, Vega, Arcturus, 61 Cygni, Sirius.]

4. How many other stars, besides these 20 bright stars, are within 20 parsecs of the sun?

[Hundreds So-called "red dwarfs," and "brown dwarfs," not readily visible because of dimness.]

5. The sun is most closely associated with a specific spiral arm of the galaxy. Which one?

[Orion arm.]

6. This spirial arm is visible as a large part of the Milky Way. From our viewpoint on Earth, where does this spiral arm appear to start, and where does it end?

[Sagittarius to Cygnus. May actually start in Ara or Centaurus or somewhere down there.]

7. What is the closest galactic star cluster to Earth?

[Big dipper. Followed by the Hyades.]

8. Where is the closest region to Earth where stars are actively being formed?

[Orion nebula.]

9. The Milky Way appears to divide into two bands in what part of the Milky Way? What causes this separation?

[Cygnus. Dark clouds of interstellar dust.]

10. What is the farthest part of the Milky Way that we can see from Earth? Where is it, and how far away is it?

[Perseus arm, about 20,000 light years. I believe we can't see objects in the External Arm beyond the Perseus Arm, with most amateur telescopes.]

i'll wait for some answers (or individual tallies of the number of questions that can be answered), before i post answers of my own.

[We may learn something from our wrong answers.]

Bill

Edited by auriga (10/21/12 12:00 PM)

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mwedel
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Re: unlearning the constellations new [Re: drollere]
      #5480635 - 10/20/12 03:59 PM

Quote:

indeed, despite your claim to have equal and diverse interests, i note that you prefer to critique rather than build on my post.




There's one more way to misinterpret a post, and you've managed it. I don't think anyone in this thread objects to the factual information you're presenting, but to your adversarial tone. So let's stop slinging mud at each other's posts and get back to the question at hand.

Appreciating the distribution of nearby stars and the 3D structure of the Milky Way is not the only way in which we need to escape what I call the tyranny of spherical astronomy. There is also the 3D structure of the larger universe: the distribution of galaxies in the Local Group, the distribution of other clusters of galaxies, near and far, and the organization of these clusters into superclusters and other large-scale structures.

My appreciation of this perspective started when I realized that as essentially stellar objects, the planetary nebulae easily visible in amateur telescopes are mostly distributed within a few hundred light years of the sun. Open clusters go out to a few thousand light years, globs are mostly at tens of thousands of light years to hundreds of thousands of light years, although only a few of those more distant ones are visible in small telescopes because of the sun's position in the galaxy. And so on out to the Local Group galaxies at a few million light years, the Virgo Cluster galaxies at tens of millions of light years, and more distant galaxy clusters at hundreds of millions of light years.

To me, one of the most interesting aspects of this is that all of the classes of objects listed above include at least a few members that are close enough in apparent magnitude, as seen from Earth, to potentially be mistake for each other--or for comets, which is how Messier got into this in the first place (and yes, I know that later on he was trying to catalogue all kinds of DSOs, not just those easily mistaken for comets).

I realize that I've neglected OB associations, dark nebulae, and other large-scale galactic features. It's because I'm coming to this as a DSO list-chaser, and it's just easier to find information on the Messier-type objects. But I'm trying to hack my way in the right direction, even though I still have a long way to go.

Anyway, starting with double stars and planetary nebulae and moving out to the other classes of objects, one can bring larger and larger spheres of space into some kind of three-dimensional understanding, if the distances to the objects are known, and also if there is some kind of framework, mental or otherwise, to hang them on. I wish I had a manually interactive 3D holographic map of the kind seen in movies (Iron Man, Prometheus, etc.). Two-dimensional representations that attempt to show the 3D galactic (and extragalactic) structure are better than nothing, but they always compress one dimension out of existence,even if it's represented as 'perspective', and I still have to do the final 3D reconstruction in my head.

Still, it's a start.


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auriga
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Re: unlearning the constellations new [Re: GlennLeDrew]
      #5480691 - 10/20/12 04:52 PM


It is good to have someone sensitive enough to language to be interested in the title of the thread, though I see it a bit differently from you.

To me it's a metaphor, and as such a recognized literary device to gain the reader's attention and make the issues more salient. Perfectly okay with me, evidently not with others, who find it adversarial or provocative.

"Beyond the constellations" is to my ear quite ambiguous, and may refer to distant galaxies, or to substituting astrophysics of star formation, for conventional star lore.

The title the OP chose instead expresses the author's intent to conceive of star patterns in terms of absolute magnitude, or in terms of distance, or position in the galaxy. His gifs express this also.

I think there is a more general issue here about which constitutes really good writing in amateur astronomy. Thankfully, some writers are able to avoid the wooden, the clumsy, and the pedestrian. Among the really good writers are Craig Crossen, Jay Freeman, Rod Mollise, Robert Burnham Jr., William Tyler Olcott, James Mullaney, Charles Wood, and some others. From his posts here, Jon Isaacs appears to me to be a very good writer.

But some of our most brilliant posters do have difficulty expressing themselves clearly, as some of the posts on collimation suggest to me. And a lot of the books on amateur astronomy, even some very useful and well-regarded ones, are undistinguished in writing style. This is okay, I greatly appreciate the information and the expertise, but I am always happy to see good writing accompanying it. The OP here has a lively style, provocative perhaps but not boring.

Bill

Edited by auriga (10/21/12 02:17 AM)


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amicus sidera
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Reged: 10/14/11

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Re: unlearning the constellations [Re: drollere]
      #5480805 - 10/20/12 06:30 PM

Many thanks for the thoughtful and very relevant OP, Drollere.

It's true that the vast majority of observers perceive and learn the stars as being fixed equidistantly on a 2-D shell above us... due to the lack of stereo effect due to distance, this is to be expected, and is still a good first step in becoming acqainted. If I may be so bold as to interpret what you have stated, I gather you feel that many stop at this point, and thus limit themselves as to their perception of the visible Universe, which tends to inhibit growth as an observer. If so, I am in agreement with you.

Your use of the term "unlearning" appears to be quite accurate in the context in which you have presented it. I fail to see how its use could be construed as either combative or unfortunate; these are emotive terms that would seem to be misapplied in this case.

That said, instead of completely discarding and hence "unlearning" the system in common use, perhaps a parallel system or systems could coexist alongside it... taking such denominators as distance, spectra and galactic distribution into account, either together or separately. This could effectively create a system that would include the diversity of distances, composition, distribution, etc., and hence provide a much deeper view of our surrounding stellar environment.

The animated maps you have supplied (very nice work, incidentally) are a step in this direction. Perhaps a whole-sky map of this sort, while still limited to a 2-D representation, would, with sufficient applied mentation, certainly expand the viewpoint of the average observer to include much more in his cognition than the "pinhole mentality of the catalog list and GOTO mount" that you refer to.

One book that might prove to be of interest in pursuit of the foregoing is the modest atlas entitled 3-D Star Maps, by Monkhouse and Cox (Harper & Row, 1989)... while quite basic, it nicely illustrates the concepts under discussion, and includes "depth" charts of not only our own stellar neighborhood, but of local galaxy clusters as well. It comes supplied with a pair of the requisite glasses to enable use of the 3-D maps.

eta: Is it just me, or has anyone else noticed that forumites are getting a wee bit touchy over trifles these days?

Edited by amicus sidera (10/20/12 07:04 PM)


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bassplayer142
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Re: unlearning the constellations [Re: auriga]
      #5480830 - 10/20/12 06:53 PM

Quote:

Bruce,
A number of points:

1. Your gifs are great and show a lot about the sky that other representations don't show. I agree with you that these alternative representations of the sky are valuable. Thanks for posting them.

2. You raise very important questions. As far as I can tell, the Herschel 400 I and II, while no doubt valuable and worthwhile, convey little understanding of the structure of our galaxy as a whole. Observing lists in general can have this limitation. So I agree with this part of your thesis as well.

3. The pinhole view is narrow in the sense that one is observing only a small portion of our galaxy. But with my 13 Ethos ( I don't have the 17) in my 16"f/4 Dob the view is perceptually wide, 100 degrees wide. Al Nagler is right about the "grandeur factor." The emotional and perceptual sense of the breadth and vastness of our universe is conveyed in part by these huge visual fields even though in terms of absolute distances they are very narrow indeed.

4. There are some guides in the area of galactic structure. Prime among them, and going far beyond Craig Crossen's Binocular Astronomy, is his subsequent book, with Gerald Rhemann, "Sky Vistas" (published by Springer). He devotes great attention to the structure of our galaxy. Another guide is Bill Tschumy's "Where is M13?" I am sure you are familiar with these but my point is that a huge amount can be learned about the structure and content of our galaxy by careful study of these sources, which you have doubtless already done.

6. If your thesis is that we need to spent time scanning the Milky Way with binoculars, looking for star clouds, dust lanes, dark nebulae, and OB associations, in order to get an understanding of and appreciation for our own beautiful galaxy, I agree entirely.

7. Where I part company with your thesis is as follows: When I look at M17 I enjoy it as an object in itself, but I try also to be aware of where it lies in our galaxy. I value diagrams like "Where is M13" that show it visually. And I devote special attention to objects that are far out toward the Perseus arm, such as the Double Cluster and one or two more distant objects in that direction. I also try to look at objects near the galactic center, such as NGC 6522 and 6528, in Baade's Window, with the realization of where they are; similarly for objects in our Orion Arm. My point here is that viewing individual objects is not exclusive of understanding the galactic structure, and that binocular study, while essential for this purpose, is not the only contributor to this understanding.

Knowing where in our galaxy an object is, adds a great deal to the pleasure of observing it and to my understanding of the object and our galaxy. To know that M54, while not outstanding visually, is probably the core of a now dispersed galaxy, enriches the visual experience.

I am also very interested in viewing the sky in terms of the absolute brightness of the stars in it. So, I always like to take a look at Zeta 2 in Scorpius, and 6231 is itself one of my favorite objects. And Rho in Cassiopeia, and P Cygni, and Wesen and Aludra in Canis Major.

As a related issue, I think the OB associations, especially in Perseus and Scorpius, are much neglected by observers. Perhaps because they are too easy to find and so don't confer much prestige on the observer?

Bill Meyers




I agree with number 5


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