The constellation Southern Cross, as its name says, is available to residents of the southern half of our planet. You will not see him from Russian territory. Nevertheless, the name of this cluster of stars is known to many "northern" inhabitants in literature, it was mentioned by the great travel romantic Jules Verne and the epic Dante. In addition to literary sources, many people know the constellation Southern Cross on the Australian flag, where it symbolizes the state of Victoria.
Earthly history of a celestial phenomenon
To begin with, the constellation Southern Cross is quite young. In ancient times, it has not yet taken shape exactly in the form that we see now, it has not received a name and, accordingly, has not been mythologized.
However, the Romans understood the constellation of the Southern Cross as asterism, that is, a certain cluster of stars called the Throne of the Emperor. That is, we can say that the earthly history of this group of luminaries began earlier than the group received its modern name. Ancient Arab astronomers also knew a star cluster at the place where the Southern Cross constellation is now located, although they called it differently.
Australians who have “free access” to the constellation have their own myth. In their opinion, the cross is two cockatoo chased by an evil spirit (the Coal Sack plays its role, which is quite symbolic, because where else can you stick the stolen).
The European Middle Ages gave rise to a beautiful legend associated with the fall of the first people. It was believed that Adam and Eve watched in tears watching the removal of the Southern Cross, which censured the act of our ancestors. Since then, they say, this constellation is inaccessible to the eyes of the inhabitants of the northern hemisphere.
Until the seventeenth century, this cluster did not stand out at all in a separate constellation, its stars were considered part of the constellation Centaurus. According to various sources, either the Bayer (in this case, it happened in 1603), or the Frenchman Royer “separated” the Southern Cross (then it happened three quarters of a century later, in 1679).
The familiar name appeared due to Magellanic swimming around the world, but was finally recorded only in the 18th century. The purpose of naming the four stars with the name “Southern” was the need to distinguish them from the constellation Cygnus, which in that era was also often called the Cross.
Constellation dimensions
Due to the excessive romanticization of the Southern Cross, people far from astronomy believe that this is a large and vibrant constellation. However, for a person not armed with a telescope, this star cluster looks like a combination of four luminaries, really depicting a slightly beveled cross. This is explained by the fact that the other stars entering the constellation are rather dim, and the naked eye distinguishes them weakly. In fact, the Southern Cross is a constellation (this photo clearly shows), consisting of a larger number of stars (there are about 30 of them). However, for constellations this is very little. For example, the Ursa Major, beloved by the northern hemisphere, includes 125 stars, and this cluster is almost twenty times larger than the so-called “big” Southern Cross.
Title mismatch
If we strictly refer to the name, then the constellation Southern Cross can be called the cross that prevents the fifth “star”, which is comparable in brightness to the four main ones and therefore visible even without a telescope. It would be more correct to say that it is perceived as a single luminary precisely without enhancing vision, since in reality it is dozens of stars of various colors. And if the spectacle is simply mesmerizing with a telescope, then for a simple person it somewhat complicates the perception of the constellation in the form of a cross.
The Importance of the Southern Cross for Orienteering
However, the romanticization of this constellation is explained quite simply. In the southern part of the globe, it is comparable to the North Star. Only if our native “pointer” helps determine where the north is, then the Cross indicates to the traveler where the south is.
The main clarification is to determine the southern direction by this constellation is much more difficult than the northern one by the Polar Star. In the Cross, only two stars point to the south: Alpha and Gamma, otherwise called Akruks and Gakruks. They form the longer axis of the rhombus. In principle, in the direction the traveler is oriented. But if a more accurate indication is needed, then this diagonal should be extended four and a half times and find there a small star with the trivial name Sigma Octane, which is located almost above the south pole. So for all these calculations you need to be almost a professional astronomer. However, the sailors of antiquity were and they were, and managed to do without modern sophisticated, but accurate instruments.
Another difficulty
In addition to all these difficulties, the orientation, in which the constellation Southern Cross helps, makes it difficult to have another similar star cluster. It is nearby and belongs to two constellations at once : Kiel and Sail. At the same time, the outlines of this asterism are disgustingly similar to the southern "pointer", for which it was called the False Southern Cross. The experienced eye can see that the diameter of the deceiver has an angle of inclination in the wrong direction, but those who sailed in the old days in these waters for the first time were mistaken and moved in the wrong direction.