Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

There is a nice image of the Milky Way, labeled with constellations, at 360°x45° panorama with constellations: Image of the Milky way - in visible light? Image source: home.arcor.de/axel.mellinger/images/mwpan45_full_c.jpg

It leads me to wonder how much we know about the Great Rift, Coalsack and other prominent dust clouds that obscure the stars in the background. Are there names for other clouds that can be distinguished by eye (in dark places)? How far away is the dust? Do we have any 3D maps of these dust clouds? My web searches haven't turned up much along these lines.

Update: I know there is a huge variety of information on the brighter nebulae and smaller telescopic Messier objects. I'm looking for information on the dust clouds "visible" to the naked eye.

share|improve this question
    
Copied from my response on Physics Stack Exchange: My bet is that there aren't really 3d maps of those sorts of structures because it is extremely difficult to judge distance accurately enough. There might be some information on approximately how deep it is, but the more fine structures of it cannot really be known that well. –  Benjamin Horowitz Jul 20 '11 at 19:30
    
@benjamin Yeah - your response prompted me to broaden the title to also include names. I've spent time memorizing the zodiac constellations - orientation and sequence - and they're great for developing a sense for the ecliptic coordinate system. But memorizing the features of the dust lanes would help ground me in a galactic context (and get me out in dark places where I can see them....) –  nealmcb Jul 20 '11 at 19:54

4 Answers 4

Astronomers have been very good at giving names to all possible dark patches, nebulae and clouds that they could find. Currently there are numerous catalogues published in professional literature and online archives. Most of the times the objects, say some dark patch, was given different names by different studies so to answer to your general question - yes, they all have their names. If you are interested in learning about them you might try to use some general planetarium-like software, say Stellarium or Google Earth has a sky feature. With those two you can get names for some of the famous ones. If you want to go further you could have a look at Simbad which is mostly for professional use, but it's still fun to poke around.

Regarding to your question on 3D distribution of those structures, we can't look at them while living inside. But from the overall distribution we have a reasonably good idea about the overall distribution of those clouds. This is not an easy task since there is so much dust and gas in our way that we have to use some different types of observations to get the picture. There are some models which produce the 3D distribution according to our current knowledge, but, as you might imagine, it is constantly changing and improving. To get an idea on how different universe looks at different wave-bands have a look at Chromoscope.

A couple of more resources (after the requested edit):

share|improve this answer
    
One more resource to look - wikisky.org –  Tigran Khanzadyan Jul 20 '11 at 21:12
    
Thanks and sorry for the confusion - I updated the question to empahsize that I'm interested in naked-eye features. Stellarium lets me search for the coal sack, but not the great rift, and I don't see either one labelled. Got any more names for me? –  nealmcb Jul 20 '11 at 21:36
1  
OK, if you are interested in those dark patches then there are several catalogues which are done in visible light. One relatively recent one comes to mind: darkclouds.u-gakugei.ac.jp –  Tigran Khanzadyan Jul 20 '11 at 21:45
1  
There is more: You could try to search Lynds dark clouds catalogue in Google. It gives numerous results and some guys evan wrote softwares to visualise everything on sky maps. The original paper by Lynds is accessible here: adsabs.harvard.edu/cgi-bin/bib_query?1962ApJS....7....1L –  Tigran Khanzadyan Jul 20 '11 at 21:55
    
Thanks, those are great atlases! If you edit them into your answer, they'll be easier for people to find. –  nealmcb Jul 21 '11 at 0:35

The man who catalogued the most dark nebulae was E. E. Barnard, the same person who discovered Barnard's Star. These nebulae are known by the numbers in Barnard's catalog, such as B.33, the Horsehead Nebula.

Barnard was one of the first people to apply photography to astronomy, and one result was a stunningly illustrated volume of dark nebulae.

share|improve this answer
1  
The most striking naked eye dark nebula is what the Australian aborigines call The Emu. The Coal Sack forms its eye, and the Great Rift is its body. Seen from a dark sky in the southern hemisphere, it is spectacular. –  Geoff Gaherty Jul 21 '11 at 0:45
    
It seems that Barnard may have been among the first to make an extensive catalog, but the references in the answer by Tigran include much more extensive catalogs and atlases. –  nealmcb Jul 21 '11 at 5:48
up vote 4 down vote accepted

I ran across a name for what I'm searching for: "dark cloud constellations". To see them, you need to experience the kind of dark skies that much of humanity grew up with. In the southern hemisphere, where the center of the galaxy can go high in the sky and cast a shadow, it is easier to discern them, and many cultures gave these figures names:

Constellation (Wikipedia):

Some cultures have discerned shapes in these patches and have given names to these "dark cloud constellations." Members of the Inca civilization identified various dark areas or dark nebulae in the Milky Way as animals, and associated their appearance with the seasonal rains.[4] Australian Aboriginal astronomy also describes dark cloud constellations, the most famous being the "emu in the sky" whose head is formed by the Coalsack.

One nice, detailed map and list of these, with lots of names, from an Inca perspective is here: www.astronomy.pomona.edu/archeo/andes/startable3.html - it would be nice to see this information used to label the image in the original question.

The Australian emu in the sky is enormous, and looks like this (stretching from nearly Aquila on the left to Crux on the right):

Update: Here are other named dark cloud constellations that can be seen with the naked eye under good conditions, besides the Great Rift and Coalsack already mentioned in the question:

share|improve this answer

You can find a really interesting map of Milky Way dust clouds in Face-on map overview on Galaxy Map:

enter image description here

enter image description here

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.