Thank you very much for that map, Case! I am quite unable to produce such things.
And thanks for your associations, Art. Indeed, Norma is the located next to Ara.
I'd like to return to astronomy and to associations that can be traced to today's APOD in a more astronomical way. As Case's map shows so clearly, emission nebula 6188, as large and impressive as it is, is only a very small part of constellation Ara.
Pictures of emission nebulae are astronomical favorites. Check out the homepages of astrophotographers like Robert Gendler or Adam Block, and see how many pictures of emission nebulae they have produced. And yet, when you look at wide-angle pictures of the Milky Way, the emission nebulae are so small, few and far between.Check out this picture of the Milky Way
. A good thing about it is that you can clearly see many emission nebulae because of their pink color. Let's try to identify them!
At far left, as far left as you can go, you have IC 405 and IC 410
, with a stellar asterism, "The Leaping Minnow", running between them.
The next pink nebula is located below the plane of the Milky Way, above the Pleiades. It's the California Nebula
The next two nebulae are the Heart and Soul nebulae
, IC 1805 and IC 1848.
The tiny round nebula hanging somewhat below th eplane of the Milky Way is the Pacman Nebula
, NGC 281.
Next we come to the faint NGC 7822
, which looks mostly like a line of reddened star located in a really dark patch of the Milky Way dust lane.
Next we come to IC 1396
, with the Elephant Trunk nebula and the remarkable reddish Garnet Star, Mu Cephei, apparently sitting on the edge of it.
The next two nebulae are the well-known North America and Pelican Nebulae
. Note in the large Milky Way picture that you can see some nebulosity to the lower left of the North America nebula. You can see it in the link I've provided here, too. To my knowledge this nebulosity hasn't got a name, but it is centered on, and ionized by, the magnificent runaway O8-type star, 68 Cygni or HD 203064.
By the way, shouldn't the Cocoon nebula
be here somewhere, too? Absolutely, but I can't find it in the Milky Way picture. It's too tiny.
The next nebulosity, instead, is a lot of scattered nebulosity which I choose to just call the Gamma Cygni nebulosity
Now you come to a long stretch of nebula-free Milky Way. We first come to a nebula whose name I haven't managed to figure out. It is centered on cluster NGC 6604, and parts of the nebula are called Lynd's Bright Nebula 71 and Lynd's Bright Nebula 72. It's a quite large nebula, but faint. In this link
, the large faint nebula centered on cluster NGC 6604 is at top right, and well-known M16, the Eagle Nebula, is below it.
M16 deserves another link too, of course. This false-color image
shows off the inner structure of M16 very well.
After M16 we have M17, the Swan Nebula. It is the site of fantastic star formation. This image
shows the "champagne flow" of M17, as the tremendous stellar winds of all the newborn O stars inside force huge amounts of gas out of "openings" in the nebula in the same way as champagne is forced out of the bottle when the cork has been removed.
The next nebula is the large, faint nebula Sharpless 2-27 around runaway star Zeta Ophiuchi
. It is seen at the very top of the image, above the plane of the Milky Way. There is apparently a meteor in the picture, too.
Almost directly below Sharpless 2-27 is M8, the Lagoon Nebula. In this picture
you can see the Lagoon nebula on the left and the Trifid Nebula on the right. I can see the Trifid Nebula in the Milky Way picture, but I can't see its pink color. It is probably too tiny.
Too the upper right of the Lagoon Nebula is a faint pink nebula. It is centered on a magnificent and very distant O-type star, HD 162978. You can just barely spot the large, faint nebula in this image
at four o'clock.
The next nebula is another large, faint nebula centered on an amazing O-type star. This nebula is located to the right of M6, the Butterfly Cluster, as seen in the Milky Way picture and in this image
. Please note that the nebula is nowhere near as bright as it appears to be here!
Then we have NGC 6357, the War and Peace Nebula, and NGC 6334. the Cat's Paw Nebula
Above them, above the plane of the Milky Way, is the large, faint nebula surrounding hot star Tau Scorpii. Unfortunately this was the best picture
I could find! Tau Scorpii is almost smack in the middle of the picture. To the right of Tau Scorpii is Sigma Scorpii, which is surrounded by a much smaller but actually brighter nebula. At upper right in the picture you can see the nebula around Zeta Ophiuchi. At 4 and 5 o'clock you can see the faint nebulosity around stars Pi and Rho Scorpii. In the middle of the plane of the Milky Way, as seen in this picture, is NGC 6357 and NGC 6334, the War and Peace and Cat's Paw nebulae.
In the Stephane Guisard picture, you can see a ring apparently surrounding a small cluster, The cluster is NGC 6281, and it beats me, frankly, why there would be a ring of nebulosity around it. It looks like an unremarkable cluster, probably at least a hundred million years old. In this picture
, you can see the cluster at about 8 o'clock, and a large, faint ring surrounding it.
More importantly, in the same picture you can see what I call "The Hook of Scorpius". In the middle of this picture
you can see the red nebulosity, IC 2648, that makes up one end of the Hook. Then there is a scattered group and then line of stars, ending in the compact, remarkable cluster NGC 6231. Then there is a triangle of stars, the brightest of which is a reddish star which is a foreground object. The other two stars, at least one of them, is probably at the same distance from us as NGC 6231. The two brightest of these three stars are called Zeta Scorpii. The faint red arc in the right part if the picture is almost certainly caused by the mighty stellar wind of cluster NGC 6231.
Okay, and what is the next nebula? Why, it is NGC 6188
in Ara, of course!
Now we come to a long stretch of nebula-free Milky Way. The next important nebula is the Lambda Centauri Nebula
. The most important part of the nebula, IC 2948, is centered around a group of O-type stars which ionize the nebula.
The next nebula is the great nebula of Carina
The next nebula is the incredibly large Gum 12 nebula
in constellations Vela, Puppis and Carina. This extremely large nebula may have been cause by a supernova, which compressed a lot of gas and pushed it outwards. The faint red arc above the plane of the Milky Way just above Gum 12 may be connected to Gum 12 and may have been caused by the same supernova. At least that's my guess. This APOD
helps you locate various nebulae embedded in the Gum nebula.
There is a faint nebula to the right of the Gum nebula which I don't recognize. However, it appears to be centered on the great Tau Canis Majoris cluster. That makes sense. Tau Canis Majoris is a great O star, and there is another O star, 29 Canis Majoris
, located relatively close by. Together these two great O stars would definitely blow out a cavity around themselves and compress the gas they have sent flying into a glowing red ring.
The next nebula is the Seagull Nebula
Now I'm sure you can see Orion
with all its nebulae hanging below the plane of the Milky Way.
The small bright round nebula in the plane of the Milky Way is the Rosette Nebula
The much fainter nebula to the upper right of the Rosette nebula is the NGC 2264 cluster, with the Cone Nebula and the Christmas Tree cluster
. Here you can see a picture of Rosette Nebula on the right and the Cone and Christmas Tree cluster nebula on the left
. You can see how much brighter the Rosette Nebula is than the Cone and Christmas Tree cluster nebula. But the latter is surrounded by a large, faint nebula.
Phew! I'm done! But if you bear in mind that I looked up all the obvious nebula in that Milky Way image, you have to admit that the nebulae in the Milky Way are pretty small, few and far between.