The constellation known as Sagittarius is a centaur. Do not confuse it with Centaurus. We have two centaurs in the sky and this one wants to be associated with the fine sport of archery. So ignore the legs and focus on the bow.
The name associated with these stars goes way back. It’s one we got from Ptolemy’s maps but it was a Babylonian thing before that. It was a centaur then also and had the bow thing going on as well, but he had wings, and two heads (one human, one panther), and a long stinger tail. So yeah, that’s a lot of special features. I’d still focus on the bow. For the record, he is aiming an arrow at Antares, the heart of the Scorpion. Fortunately the Greeks trimmed him down to a basic centaur. There are a variety of back-stories about the archer, many of which end with… you probably guessed it, Zeus turned him into stars and put him in the sky.
The Milky Way is the widest and the brightest in Sagittarius. That’s because on summer nights we are looking inward towards the very heart of our galaxy. There is a lot of crap in the way, mostly billions and billions of stars. There is also a lot of dust. The galaxy is a big construction project, cranking out lots of lovely stars and planets and what not, but it doesn’t do a lot of clean up after the fact. So our view of the center is blocked by big-ass dust bunnies. And space dust is very efficient at blocking light because the little itty bitty bits of dust are about the size of the wavelengths of visible light. Some wavelengths like radio waves get through better than others but I would still take your whole MP3 collection with you if you’re heading over there to the core.
Speaking of the core, we’ve noticed some strange behavior by the stars in that region. Some of them are moving so fast that they should go zinging right out of the galaxy. Some of them actually are zinging out. Officially those are called hypervelocity stars but I call them zingers. Anyway, the only explanation that seems to make sense is that something interior to their orbits weighs about 4 million times as much as the sun. Something black that ends with “hole.”
The view in the direction of the innards of our galaxy is a such a busy one that there is a lot to talk about. Here are some of the highlights.
M8 is The Lagoon Nebula. In amateur telescopes it looks like an island surrounded by the black sea of space, with a swooping lagoon penetrating one side. It somewhat resembles an aerial view of Gilligan’s Island. Remember, all sorts of interesting things would wash up on the shores of the lagoon on that show, including the Harlem Globetrotters.
Anyway, if you are ever marooned at M8, there are lots of points of interest you could visit and make a show about. One of them is a huge tornado of hydrogen gas being whipped up by a massive O-type star which is super-heating a piece of the nebula.
M17 is The Swan Nebula or The Omega Nebula, depending on which way you tilt your head and squint your eyes. Some astronomers have called it The Checkmark Nebula and some have called it The Horseshoe Nebula. I guess it all depends on what sort of thing most interests you, what it is that you are really into. I call it The Nachos Nebula.
The Swan-Omega-Checkmark-Horseshoe-Nachos Nebula is one of the most energetic star-forming regions in the galaxy.
M20 is The Trifid Nebula and it is a two-fer. First you notice the redish, pinkish, magenta-ish part from the fluorescence of hydrogen atoms, excitedly pronouncing the birth of nearby stars. And right next door we have the bold blue light from those same baby stars being reflected by bits of dust leftover from the dried decayed bodies of old dead stars, the scattered remains of an ancient epoch.
Emission and reflection. Something old and something new. It’s two different generation’s taste treats rolled into one, like butterscotch flavored Skittles.
If you connect-the-dots of the brighter stars in Sagittarius it produces a teapot, the traditional short-and-stout type with an obvious handle and spout, slightly tipped over with Milky Way coming out. In addition to the bright stars there is enough tuck and fold to the crowded star fields in the background for your mind to make a decent 3D teapot out of it, provided you get out away from the city on a moonless night, relax and let your mind wander, and eat some magic mushrooms.
But before you agree to go on a date, ask to see their long-form birth certificate. Then wait until their birthday and measure the right ascension of the sun on the ecliptic from its position on the vernal equinox. You need to consider and take into account the eastward precession of the equinox since the iron age due to the slow but significant wobbling of the earth.
Dating now days is such a precise science.