Sagittarius the Archer The archer also happens to be a centaur, but don’t confuse him with Centaurus. We have two of these man-horse thingies in the sky. Centaurus is the one with the Aussie accent. Sagittarius is the one shooting the snake fighter in the toe. The bright stars of Sagittarius form a very convincing teapot shape. It’s one of those classic story book teapots as in “here is my handle, here is my spout.” But then “tip me over and 400 billion stars come blasting out.” Simply connecting the stars of the teapot presents the abstract version but there are enough puffy eddies and swirls and star clouds to the galactic nebulosity in that direction, that your brain can actually make a pretty decent 3D teapot out of it, providing you get out of the city where the sky has a nice contrast and texture. And take some mushrooms. M8 is the Lagoon Nebula because in a telescope it looks like an island with a large lagoon opening out to the sea. It is quite large and bright to the naked eye, lying in the knotted stellar braids of the summer Milky Way. It is an emission nebula, a nursery of newborns, like the Eagle Nebula. Frankly M8 reminds me of an aerial shot of Gilligan’s Island. Remember? Weird plot devices were always washing ashore in the lagoon on that show. Remember? Gilligan’s Island, Petticoat Junction, Green Acres, and Beverly Hillbillies were all on prime time TV during the “why cousins shouldn’t marry” era of home entertainment. M17 is the Swan or the Omega, a bird on a lake or a Greek letter, depending on just how distortedly abstract you are willing to allow either of those things to be. Basically it’s warmed up hydrogen atoms, so incredibly excited by the arrival of nearby stars that their electrons are starting to ricochet around in quantum orbitals, especially those that produce 656.28nm wavelengths of photon energy, which our brains tend to interpret as a cross between a subtle shade of raspberry and a harsh magenta. Star hopper types live for that kind of excitement. M20 is called the Trifid Nebula because it is divided into three parts, just like Julius Caesar did to France. Technically it would be Gaul not France, since I think the Franks were as yet only a small part of that ethnography. But not only does the Trifid have the glowing reddish hallmark of star birth, it has a bonus reflection nebula of bluish light scattered by a nearby cloud of dust particles. This Messier is a big hit at parties where everyone read the classics in original latin. For some strange reason there were posters of Messiers on the bridge of the USS Enterprise on the original Star Trek series. I always thought that was a bit like going to see Paris and taking along a picture of the Eiffel Tower. You can just look out the stinking window for criminy sakes. Someone must have agreed with me at some point because eventually the Picard generation came along and beamed them down or something (they really have to go number one). If you look just west of the spout of the Sagittarian teapot you will be looking into the very heart of the Milky Way Galaxy. There is good reason to think that you are also looking towards a supermassive black hole. At least that’s the simplest explanation for the weird stuff we detect going on. There are stars over there moving so fast that they should have gone zinging into intergalactic space a long time ago. Something dense is holding them back. Something dense like the meatballs at Olive Garden. And also there are gases squirting out of the neighborhood near the center like a fire hose. We see the fire hose effect happening in lots of galaxies. Now days we suspect that most if not all galaxies have supermassive black holes in the middle. It’s apparently something that is just “baked into the cake” as they say. You can’t see all the way to the center of our galaxy. You can’t see far at all in that direction, not with my telescope anyway. The cloud of smog hanging over Sagittarius is impenetrable with amateur scopes. Professionals can peek through the cloud somewhat at certain wavelengths but it’s still pretty mysterious. Even the cloud blocking our view itself is mysterious. Mostly what we know about the cloud is that it’s dark and it probably smells like Tacoma. To get the big picture you have to realize how relatively tiny our planet really is. If our whole solar system could fit in a coffee cup, say a triple grande caramel macchiato with extra whip, then our galaxy would be the size of the North American Continent. You can put a lot of coffee cups in North America. And we do. And I’m only talking about the bright disk of the galaxy. If you include the rural delivery routes out there in the halo with the globular clusters, then we’re talking about comparing a coffee cup to the whole Earth. No wonder we can’t see the core, although, I wouldn’t be surprised if they have a Starbucks there. Those things are everywhere. The other day I went into a Starbucks, and there was another Starbucks!
Posted on: Sun, 09 Jun 2013 19:34:45 +0000