Crux The Southern Cross Astronomy Visual Guide to the Constellation
Crux The Southern Cross Astronomy Visual Guide to the Constellation
Crux The Southern Cross Constellation
This world-famous constellation lies exactly south of Crater, at a distance of about thirty degrees from the south pole.
The precession of the equinoxes has been said to be carrying the Cross slowly southward, and that this constellation was last seen on the horizon of Jerusalem about the time of the Crucifixion. The Southern Cross did not receive its name, however, until after it had attracted the attention and excited the admiration of the early circumn-avigators.
It seems to have been named early in the sixteenth century. Dante's lines in the first canto of the "Purgatory " have often been supposed to refer to this constellation (not then called the Cross), because of its four bright stars :
To the right hand I turned and fixed my mind On the other pole, attentive, where I saw Four stars ne'er seen before save by the ken Of our first parents. Heaven of their ray, Seemed joyous. O, thou northern site, bereft Indeed, and widowed, since of these deprived.
Amerigo Vespucci, on his first voyage, saw the Cross, and exultingly wrote that he had beheld Dante's "four stars." As other navigators pressed into the Southern seas, the fame of the Croce maravigliosa, as Pigafetta called it, spread over the world. Pigafetta thought it more glorious than all the other constellations. It appeared on a celestial globe by Mollineux in 1592. Acosta, in his history of the West Indies, published in 1590, told how the Spanish settlers were accustomed to use the Southern Cross as a clock, reckoning the hour by its inclination to the horizon. Readers of the romance of Paul and Virginia will recall a reference to this use of the constellation of the Cross. The intensity of religious feeling in the time of the great geographical discoveries no doubt added immensely to the interest felt in the Southern Cross, as well as to the appreciation of its beauty by those lucky enough to see it. Its splendor lost nothing in their descriptions, and it soon captured the imagination of all Christendom. Yet its stars had been known to the ancients when the constellation shone over the middle northern latitudes, and they had not, apparently, given it a separate name. It was a part of the constellation Centaurus in Hipparchus's time. Essentially it is a constellation associated with the days of discovery and early conquest in America.
Thou recallest the ages when first o'er the main My fathers unfolded the ensign of Spain, And planted their faith in the regions that see Its imperishing symbol ever blazoned in thee. - Mrs. Hemans.
Its renown is still so wide that few travelers with an interest in astronomy visit the southern hemisphere without recording their first impressions of this constellation.
The Southern Cross - A Visual Guide to the Constellation
The Southern Cross consists essentially of four bright stars arranged as if at the ends of the two sticks of a kite, somewhat awry. The larger beam, about six degrees in length, points to the pole. The four stars are, respectively, of the first, second, second, and third magnitudes. The largest star, Alpha, is at the base of the figure. Gamma , of the second magnitude, at the top of the cross, is orange-colored. The other stars are white. Alpha is a beautiful telescopic double.
A famous telescopic object in the Southern Cross is the colored cluster surrounding the little star Kappa. Sir John Herschel, the discoverer of this object, compared it to "a gorgeous piece of fancy jewelry," on account of the many colors displayed. There are several red stars, and others imitating emeralds, sapphires, and topazes. Different observers since Sir John Herschel's time have been differently impressed by this curious cluster, some describing it as exquisitely beautiful, and others finding that the only colors especially noticeable are the reds.
The Coalsack Nebula present in Crux is a prominent dark nebula in the southern skies. The Coalsack is visible to the naked eye as a big dark patch in the southern Milky Way in dark skies. The commonly named Jewel Box is an Open Cluster NGC 4755, also known as Kappa Crucis. The Jewel Box was discovered by Nicolas Louis de Lacaille in 1751–1752. It lies at a distance of 6,900 light years and is composed of approximately 100 stars spread across an area of about 20 square light-years.
How To Find The Southern Cross Constellation
There are several (three) crosses one can make out in the southern skies. The Southern Cross is the smaller one of the three, and its brightest star (Acrux) is at the bottom of its cross. Acrux is the brightest star of the constellation, and is easily found in the sky from the pointers of Centaurus (Rigil Kentaurus and Hadar) across the sky. The Southern Triangle stars also point towards Acrux if you follow the pointers across similarly from Centaurus.
Using the Southern Cross Constellation to Find South in the Southern Hemisphere
You can use the following figure to find the South Celestial Pole (SCP):
Read more here:
Find South using the Southern Hemisphere Pointers
