¡SkyCaramba! Weekly astronomy blog for the week ending November 22, 2014
For northern hemisphere observers, here’s a challenge. See if you can spot one of the southern birds among the constellations. Depending on how far north you are, you may not see all of it. But if your south horizon is clear, you might spot it in the early evening.
Krane Grus is the name given to a constellation created in the late 16th century when some astronomers felt the southern star charts were too empty. Krane is Dutch. Grus is Latin. Both words describe a bird called a crane. In the 17th century, some sky watchers thought they saw a different bird there. They tried to popularize the name Phoenicopteros, which means flamingo. It didn’t fly. Pardon the expression. Eventually, the name was just Grus.
The only named Star in Grus is Al Nair. That’s Arabic for “the bright one”. A longer form of its name from long ago would have told us it is the bright one in the fish’s tail. That’s an odd name for a member of a constellation that is a bird. But prior to this and other stars nearby being rendered a crane, they were part of Piscis Austrinus, the southern fish.
The easiest way to find Al Nair is to find Fomalhaut, the brightest star in what’s left of Piscis Austrinus. Al Nair is south and a little west of it by 20°. You will not see it north of about 42°. But you might see a few other stars that make the top of the bird. All of Grus is visible south of about 35° north. Around 50° south, the bird passes overhead. However, this time of year, the sun is up when it does. So some southern hemisphere observers will have to wait until later in the evening to see it.
Since Grus is such a new constellation and it was formed by scientists instead of story tellers, there are no legends associated with it. But we may let its stars inherit the old tales of the southern fish in the water stream poured by Aquarius to the north.