The Southern Cross is the smallest constellation in terms of area, but at the same time it has incredible beauty.
Young, small, but incredibly beautiful
Looking even with the naked eye at the southern hemisphere of the starry sky, you can easily detect about three dozen stars forming this constellation, but for the most part these are all faintly luminous stars. Of these, only four of the brightest stars - α, β and γ Southern Cross (the first in stellar magnitude) and δ (the second in stellar magnitude) - form a clearly visible cross-shaped figure in the sky.
The constellation Southern Cross is relatively young by astronomical standards; the first information about it in astronomical practice appeared thanks to the French astronomer Nicolas Louis de Lacaille in the 18th century. However, the generally accepted name for this constellation came into use long before this, even during Magellan’s circumnavigation of the world, and was used by navigators to distinguish it from the “Northern Cross,” which in the Middle Ages often called the constellation Cygnus.
"Coal Sack" and "Box of Diamonds"
Dark Coalsack Nebula
The Southern Cross constellation, in whose vastness the “Coalsack” is located, is one of the dark nebulae closest to planet Earth. The distance to it is 490 light years. The “carbon bag” is a cloud of high-density cosmic dust that absorbs the light emitted by distant stars and appears as a dark spot on the lighter Milky Way, clearly visible to the naked eye. Clusters of cosmic dust, such as the aforementioned “Coal Sack,” have the property of not only scattering and absorbing radiation passing through them, but also polarizing them.
NGC 4755 or Diamond Box
To the east, the constellation is bordered by the open cluster NGC4755, commonly known as the “Box of Diamonds,” a small group of stars of completely different colors that sparkle brightly in the night sky. The total brilliance of all the stars in the “Box of Diamonds” is 5.2 magnitudes. The “Box” is located at a distance of more than 7,500 light years from planet Earth. This cluster of stars was discovered by the French astronomer Nicolas Louis de Lacaille in 1751-1752, who was engaged in astronomical observations in southern Africa.
Location on the starry sky
The Southern Cross is a constellation that is absolutely invisible on Russian territory because... its location is far from the celestial equator, in the south. From the east, north and west, the “Cross” is surrounded by the stars of Centaurus (Centaur), and on the southern side it is adjacent to the “Fly”. Finding this constellation is very easy, because... it represents a bright, distinct figure. Help in the search for the “Cross” can also be provided by a pair of fairly bright Centauri stars, the star Rigil Centaurus (a Centauri) and Hadar (b Centauri), located slightly east of the “Southern Cross”. If you draw an imaginary straight line to the west through these stars, it will definitely point directly to the “Southern Cross”.
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The vault of heaven that we see above us is called only half of the entire sky, the northern hemisphere. But what can be observed in the sky of the southern hemisphere, hidden from us by the curvature of the earth’s surface? What kind of stars are there?
We already know most of them. For example, when the constellations Auriga And Perseus stand in the north, above the very edge of the sky, while under them, somewhere deep there - under the edge of the sky, against the southern side of the earth, our shining ones are hiding: Orion, Big And Small Dog, a lion. On the contrary, in winter, when Orion flaunts on the southern side of the sky, at this time in the north there are Lyra And Swan, and below them, below the edge of the sky, against the underside of the globe are Eagle, Bootes, Virgo, Ophiuchus.
These constellations, as you remember, occupy the entire southern side of the sky at the time when they rise in our sky. Therefore, we saw the whole half of that mysterious sky, which for us is, as it were, “underground.” We did not see only one fourth of the entire celestial space, namely that part that is located under the edge of the sky in the south. To see this quarter of the sky and its stars, you need to go there, to the south, reach “the edge of the sky” and look further down.
Of course, there is no edge of the Earth, because the Earth is a ball, there is no edge of the sky, because the sky is an infinite space surrounding the Earth on all sides. But there is an edge visible us of the sky, and this edge is located exactly where we see it. For example, on a winter evening, the edge of the sky in the south is under Sirius, where one of the lower stars of Canis Major sparkles low and low.
Instead of reasoning, let's go on our imaginary journey to the south. - Don’t forget that we are traveling on a winter evening, when Auriga, Taurus, Orion, and Sirius are burning on the southern side of the sky. - We travel, for example, from St. Petersburg directly to the south, and with the speed of thought.
Here we are in Crimea. Let's look up. - Bah!
Ancient astronomers, peering into the night sky, noticed that some stars were located close to each other, while others were far away. Nearby luminaries were united into groups or constellations. They began to play an important role in people's lives. This was especially true for the sailors of merchant ships, who used the stars to determine the direction of movement of their ships.
The first constellation map appeared in the 2nd century BC. uh. It was created by one of the greatest Greek astronomers, Hipparchus of Nicaea. While working at the Library of Alexandria, he compiled a catalog of 850 stars visible to the naked eye. He distributed all these luminaries among 48 constellations.
The final point on this issue was put by the Greek astronomer Claudius Ptolemy in the 2nd century AD. He wrote his famous monograph "Almagest". In it he outlined all the astronomical knowledge that existed at that time. This work was unshakable for a whole millennium until the appearance of the greatest scientist from Khorezm, Al-Bruni, at the beginning of the 11th century.
In the 15th century, the German astronomer and mathematician Johann Müller (not to be confused with the biologist Johann Peter Müller) founded one of the first astronomical laboratories in Nuremberg. On the initiative of this respected master, astronomical tables based on the works of Ptolemy were published.
These first maps of the starry sky were used by such famous navigators as Vasco da Gama and Christopher Columbus. The latter, guided by them, crossed the Atlantic Ocean in 1492 and reached the shores of South America.
The German artist and engraver Albrecht Dürer became acquainted with the works of Johann Müller, who is better known under the nickname Regiomontanus. It is thanks to his skill that in 1515 the first printed map of the constellations appeared. Those on it were depicted in the form of figures from Greek mythology. This was the beginning of the publication of celestial atlases.
They tried to reflect the brightness of the stars in descending order. For this they began to use letters of the Greek alphabet. The brightest luminaries within the constellations were assigned the letter "alpha". Then came the letter "beta", "gamma" and so on. This principle is still used today.
In the 17th century, Polish astronomer and telescope designer Jan Hevelius compiled a catalog that included 1,564 stars. He also indicated their coordinates on the celestial sphere.
The modern names of the constellations and their boundaries were finally established by international agreement in 1922. There are 88 constellations in total, and their names are mostly borrowed from ancient Greek mythology. Each cluster of stars also has a common Latin name. This is so that astronomers speaking different languages can understand each other.
constellation map,
located in the sky of the Northern Hemisphere
The picture above shows celestial map of the Northern Hemisphere. It includes the following constellations: Andromeda (1), Ursa Major (2), Auriga (3), Bootes (4), Coma Berenices (5), Hercules (6), Canes Venatici (7), Dolphin (8), Dragon (9), Giraffe (10), Cassiopeia (13), Swan (14), Lyra (15), Chanterelle (16), Ursa Minor (17), Little Horse (18), Little Lion (19), Pegasus (21 ), Perseus (22), Lynx (23), Northern Crown (24), Arrow (25), Triangle (26), Cepheus (27), Lizard (29), Hydra (33), Unicorn (35), Whale ( 43), Canis Minor (47), Orion (53).
The white circles contain the numbers of the Zodiac constellations: Aries (77), Taurus (78), Gemini (79), Cancer (80), Leo (81), Virgo (82), Pisces (88).
The figure below shows celestial map of the southern hemisphere. These include: Ophiuchus (11), Snake (12), Eagle (20), Shield (28), Canis Major (30), Wolf (31), Raven (32), Dove (34), Altar (36), Painter (37), Crane (38), Hare (39), Goldfish (40), Indian (41), Keel (42), Compass (44), Poop (45), Flying Fish (46), Microscope (48 ), Fly (49), Pump (50), Square (51), Octant (52), Peacock (54), Sails (55), Furnace (56), Bird of Paradise (57), Cutter (58), Sextant ( 59), Grid (60), Sculptor (61), Table Mountain (62), Telescope (63), Toucan (64), Phoenix (65), Chameleon (66), Centaurus (67), Compasses (68), Clock (69), Chalice (70), Eridanus (71), Southern Hydra (72), Southern Crown (73), Southern Fish (74), Southern Cross (75), Southern Triangle (76).
The white circles show the numbers corresponding to the following Zodiac constellations: Libra (83), Scorpio (84), Sagittarius (85), Capricorn (86), Aquarius (87).
constellation map,
located in the sky of the Southern Hemisphere
The most famous constellation in the Northern Hemisphere is Ursa Major. These are 7 bright stars forming a bucket. If you draw a straight line through its “wall” opposite the “handle” (the stars Dubhe and Merak), then it will rest against the North Star, that is, it will indicate the northern direction. Over the centuries, the position of these stars in the sky changes. Therefore, several thousand years ago the outline of the ladle looked different than it does today.
The constellation map would lose a lot without Orion. Its brightest star is called Betelgeuse. And the second brightest is called Rigel. Three second magnitude stars form Orion's belt. To the south you can find the brightest star in the night sky, called Sirius. It is part of the constellation Canis Major. Still, the diversity and beauty of the night sky is impossible to describe. This must be seen and admired by the cosmic forces that are capable of creating such splendor.
Big dog
In the Southern Hemisphere, the appearance of the starry sky changes to opposite, when compared with the North. The movement of the stars here occurs from right to left, and although the Sun rises in the east, the point of the east itself is located on the right, in the place of the west.
Canis Major is one of the brightest, albeit small, constellations located in the southern hemisphere of the sky. The constellation contains the brightest star (after the Sun) - blue-white Sirius, whose magnitude is -1.43.
Translated from Greek, seirios means “brightly burning.” The brightness of the star can be explained by two factors: firstly, the small distance to the star (only 8.6 light years) and its luminosity, which is 23 times greater than that of the Sun.
Wolf
Wolf is a constellation of the Southern Hemisphere, lying on the edge of the Milky Way. On a clear and moonless night, about 70 stars can be seen with the naked eye in the constellation, but only ten of them are brighter than fourth magnitude. Two of them are visible from Russian territory.
Crow
Raven is a small and very beautiful constellation in the southern hemisphere of the sky. Its stars form an irregular quadrangle southwest of Virgo. However, in this figure it is quite difficult to see the bird, which was depicted in ancient atlases at the site of this constellation. In total, on a clear moonless night, about 30 stars can be seen with the naked eye in Raven.
Hydra
Hydra is one of the longest constellations located in the southern hemisphere of the sky. The brightest star is Alphard (alpha Hydrae), has a magnitude of 2.0. This red variable star is 30 parsecs away from Earth. Another variable is the long-period star R Hydrae; located next to the star near Hydra. It resembles the star Mira Ceti: its maximum brightness reaches 3.0", the minimum is 10.9", which makes this star invisible to the naked eye. The period of change in its brightness is more than a year - almost 390 days.
Pigeon
The Dove is a small constellation in the southern hemisphere of the sky. Under good visibility conditions on a clear and moonless night, about 40 stars can be seen with the naked eye in the constellation. Of these, the two brightest stars have a magnitude of 3 and two have a magnitude of 4. The rest are at the limit of visibility with the naked eye. The stars of the Dove do not form any characteristic geometric figure.
Unicorn
Monoceros is the equatorial constellation of the southern hemisphere. On a clear and moonless night, up to 85 stars can be seen in the constellation with the naked eye, but these are mostly faint stars. Only the five brightest have magnitudes 4 and 5. The Unicorn stars do not form any characteristic geometric figure and do not have their own names. A very interesting star is T Monoceros, which is a long-period Cepheid. Its gloss changes from 5.6 to 6.6 in 27 days.
Constellation map
southern hemisphere
Constellations are arbitrarily taken star groups, as they are visible from the earth and completely independent of the actual distances and possible mutual connections of the stars. The division of stars into constellations dates back to ancient times. Most of the constellations handed down to us by the Arabs from the Greeks undoubtedly originated in the primitive pre-Semitic cultures of Mesopotamia. The main place among them is occupied by the zodiacal constellations. The themes for the zodiacal constellations were the hoary legends of primitive humanity, ideas about its destinies, and, less often, the personification of astronomical and meteorological phenomena. The most ancient names of constellations were abbreviations for myths.
Astronomer Jan Hevelius
Ptolemy in his work "Almagest" canonized the following 48 ancient constellations, which still bear the name Ptolemy. Zodiac constellations: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces. Northern constellations: Ursa Major, Ursa Minor, Draco, Cepheus, Cassiopeia, Andromeda, Perseus, Bootes, Northern Crown, Hercules, Lyra, Swan, Charioteer, Ophiuchus, Serpent, Arrow, Eagle, Dolphin, Foal, Pegasus, Triangle. Southern constellations: Whale, Orion, River, Hare, Canis major, minor, Ship, Hydra, Chalice, Raven, Centaurus, Wolf, Altar, Southern Crown, Southern Fish. Ptolemy did not consider Coma Berenices a separate constellation.
Arab stargazers, in addition to lunar houses, gave various names for individual bright stars. Having become acquainted with the astronomy of the Greeks and translated Ptolemy's Almagest, they changed some of the names according to the position of the stars in the drawings of the Ptolemaic constellations. In the 12th century, a Latin translation of the Almagest was made from Arabic, and in the 16th century, directly from Greek, based on found manuscripts. The stars of the southern hemisphere, unknown to Greek astronomers, were divided into constellations much later. Some of them were planned by the Arabs.
There is no doubt that the navigators of the 15th and 16th centuries (Vespucci, Corsali, Pigafetta, Peter of Medinsky, Gutman) gradually assembled new constellations during their travels to the southern seas. They were put in order by Peter Dirk Keyser. During his stay on the island of Java (1595), he determined the locations of 120 southern stars and placed constellation figures on them. The following 13 constellations were included, based on Keyser's inventory, in the atlases of Bayer (1603) and Bartsch (1624): Phoenix, Goldfish, Chameleon, Flying Fish, Southern Cross, Water Snake, Fly, Bird of Paradise, Southern Triangle, Peacock, Indian, Crane, Toucan. Of these, the Southern Cross was known to Ptolemy and formed part of the Centaurus.
The current names of constellations and stars represent an amalgam of these lists and translations. Ancient drawings of constellations are completely lost. Only distorted figures on Arab globes of the 13th century have reached us; for example, on a globe in the Borghese Museum in Veletri (1225), in the mathematical society in Dresden (1279), in the London astronomical society, etc. At the beginning of the 16th century, the famous Renaissance artist Albrecht Dürer drew constellations according to their description by Ptolemy.
Unfortunately, not a single authentic copy of Dürer's drawings has survived. Dürer's drawings, modified by other artists, were reprinted in the star atlases of Bayer (1603), Flamsteed (1729). Then the figures of the constellations of the latest layout appeared. Currently, constellation drawings are no longer printed. The credit for banishing the “menagerie” from astronomical atlases belongs to Harding. He published a celestial atlas in 1823, where only the boundaries of the constellations were plotted.