History UsefulNotes / Constellations

Well, it's just a Man's invention. Despite [[ConstellationsAsLocations what some science fiction works will tell you]], constellations ''do not'' exist in nature. When the ancient people observed the night sky, they noted that some stars make geometrical figures. Their vivid imagination caused them associating these figures with animals, objects, or legendary human characters. Apart from some rare exceptions, this resemblance is ''very'' debatable[[note]]And more after the IAU defined their limits back in 1922 as commented below, without too much care about said associations[[/note]].

As ancient people used to think the Sky was just a huge dome above the Earth, they made the mistake to think the stars within a constellation are ''actually'' close to each other. We modern people, too, tend to do the same error, even when accepting the sky is not a "celestial dome" but a boundless extension of space outside the Earth. Popular media contribute to all this, for example Sci-Fi stories telling us a space traveller can easily go to a constellation to another with its spaceship. Actually, constellations are just simple areas in the sky whose boundaries were definitively decided on in year 1922 by an International Convention -- before that, those boundaries were quite indistinct. Within each area, stars are ''not'' close to each other (apart from those grouped in clusters, see further, or some as Ursa Major and Orion where some of the stars that form them share a common origin and their distances to us are similar); they aren't even at the same distance to us. One star that seems coupled with another in the sky can even be ''10 times'' more distant from us than its neighbor. The typical figures of the constellations would totally disappear if we could go out of the Solar System and see, for example, the sky at a distance of 100 light years from Earth. All the visible stars in the sky pertain to our Galaxy, more precisely the galactic portion closest to the Solar System -- the more distant stars visible without binoculars or a telescope are about 3,000 light years from here: the whole Galaxy is 100,000 light years wide.

Also note that the stars within a constellation are neither of the same luminosity, nor are they of the same color; two stars can appear the same brightness but one can actually produce 1,000,000 times more light than the other, but is 1,000 times more distant[[note]]Not 1,000,000 times; remember the Inverse Square Law[[/note]]. Colors vary from red to light blue, passing throughout orange, yellow (our Sun is yellow), and pure white -- green stars do not exist. This coloration is tied to the temperature of the stars' surface: curiously, red stars are the "coldest" (about 4,000 C°), then the orange, yellow, white, and finally the hottest of them all, the blue ones (up to 40,000 C°). Our Sun is about 6,000 C°. Finally, it's worthy of note that the stars making the figure of a constellation do not appear with the same luminosity when live-observing, [[note]] And, of course, there are NOT lines linking them, they are only a means in astronomy books to aid the reader to better memorize the figure, and different books can link the stars of a constellation in different ways.[[/note]] and that they are ''not'' the only stars of the constellations: they contain dozens and sometimes hundreds of other fainter stars visible to the naked eye, and millions more when watching with a telescope.

** If you live in the Earth's Northern Hemisphere Orion is a winter constellation. Even though is called "the Hunter", its portrayal looks more like a warrior seen from the front. Orion is shown lifting a mace and a shield (both signed by faint stars) to defend himself against the charging Bull nearby, and has also a sword hanging from his belt. The belt is signed by the aforementioned three central stars, and is just on the celestial equator; the shoulders and the feet are symmetrically placed above and below the equator, and are signed by the stars of the "rectangle". Orion's right shoulder and his left foot are marked by two of the brightest stars in the Sky: Betelgeuse & Rigel, [[note]] Both are Arabic words meaning [[ExactlyWhatItSaysOnTheTin shoulder]] and [[ExactlyWhatItSaysOnTheTin foot]] respectively.[[/note]] both hundreds of light-years far from us. Rigel has the letter "Beta" and thus should be less-luminous than Betelgeuse (the "Alpha" star); actually Rigel is brighter than Betelgeuse, and the 7th brightest in the whole firmament -- however, note that Betelgeuse slightly changes its luminosity periodically, and can be the brightest star in certain moments. Making their constellation even more attractive, the two stars have contrasting colors: Rigel is blue, Betelgeuse is red. Both belong to the "super-giant stars" category, being even bigger than "simply-giants" like Arcturus. Rigel's diameter is about 80 times greater than the Sun's; if placed at the center of the Solar System, Rigel would swallow Mercury in its orbit. But even Rigel is a tennis-table ball when compared with Betelgeuse. This star has a diameter 1000 times greater than the Sun, and is one of the biggest stars in the whole Galaxy; if put in the place of the Sun, Betelgeuse would swallow the whole Inner Solar-System -- Mercury, Venus, Earth, Mars, the Asteroid Belt, and maybe even Jupiter!! Among the stars known since antiquity, Betelgeuse is arguably the biggest. In other world, Betelgeuse could contain 10,000,000 Suns inside it. [[note]]Remember that the Sun could contain about 10,000 Earths, giving an effective idea about how immense the stars can be.[[/note]] Astonishingly, Betelgeuse's total mass is only 50-80 times the Sun. This means its density is extremely low: an amount of Betelgeuse's matter as big as a house would weigh like a sand-grain on Earth. Moreover, being a red star, the surface of Betelgeuse is colder than the yellow Sun and much colder than the blue Rigel. Despite its smaller diameter, Rigel has about the same total mass of Betelgeuse and produces even more light than the latter; one day Rigel will become a red super-giant the size of Betelgeuse. Both Rigel and Betelgeuse are super-massive stars at the end of their life, with Betelgeuse in a more-advanced phase than Rigel (as recently as TheNewTwenties Betelgeuse has changed noticeably its brightness, and some speculate that it could explode soon becoming a spectacular Supernova as bright as a half-Moon!). When born with a mass much bigger than the Sun, stars only live few million years: Rigel & Betelgeuse were still non-existing when the dinosaurs populated the Earth! After ending their internal "fuel" of hydrogen they become enormously inflated, and finally explode with unimaginable violence: the Supernova indeed. All what remains from the former super-giant is a "pulsar" or even a Black Hole -- to learn more, see Taurus in the Zodiac section and the Useful Notes about UsefulNotes/BlackHoles.

** Ursa Major (meaning the "greater she-bear" in Latin) is the biggest-by-area constellation in the Northern Hemisphere and the 3rd in the whole sky. However, the familiar group of seven stars people associate with the Great Bear is only the brightest part of the constellation, and the only one non-astronomy books usually portray. It marks only the hindquarters and the (overly long) tail of the animal, while the remaining body is much more extended but signed by faint stars (the bear's paws are marked by three couple of starlets), and gets usually unobserved by non-expert watchers. The constellation appears high in the Sky in Spring, but may be low near the North Horizon (or even below it) in Fall. The group of seven bright stars is called the Big Dipper or the Plough in English, [[IHaveManyNames but is variably named across the languages and dialects]]: the Wagon, the Great Cart, Charles' Wain, the Seven Oxen, and so on. One of the stars of the "tail" is a famous double-star: Mizar. Its fainter companion, Alcor, is usually distinguishable from Mizar (the main star) only by using the binoculars or a telescope, even though some sharp-eyed people can tell the two stars apart with their naked eyes. [[note]]Double-stars are stars so-close to each other in the Sky they visually appear like one single star. Triple and multiple stars are also existing in the firmament. In some cases they are really close in the space and tied by gravity (the really double / multiple stars); others are only incidentally in the same perspective but at different distances from us. Mizar & Alcor belong to both cases: they are not close to each other in the space, but each one is made of two or more stars which are ''really'' orbiting together in the space. [[/note]] Ursa Minor (literally "the lesser she-bear"; also called the Little Dipper - Plough - Wagon - Cart - etc.) is so-called because resembles a miniature version of the "big dipper" but with a more curved "handle". Only three of the seven main stars are visible from a city or a town: the Alpha (aka the Polar Star), and the two at the opposite end. Since the Polar appears still, the Little Bear seems turning around the North Pole with the end of its "tail" fixed in the Sky. Contrary to what is often believed, the Polar Star is ''not'' the brightest star in the Firmament (the record-holder is Sirius in the Great Dog), nor is it an especially-luminous star. And is not actually fixed in the Sky; it too turns imperceptibly around the actual North Pole. Finally, it has not always been THE polar; see below to learn why.

** '''The Pentagon''': The most famous part of '''Auriga''', even though one of its corners is at the same time one of the Bull's horn-tips, and thus should be more properly placed in the next section.

** '''The Kemble's Cascade''': another group of starlets, this time in '''Camelopardalis'''.

** '''The False Cross''': Composed of Delta Velorum, Kappa Velorum (both from '''Vela'''), Epsilon Carinae & Iota Carinae (both from '''Carina''') -- so in a sense, this asterism is inside '''Argo Navis''', a defunct constellation today -- this asterism is so-named due to its close resemblance to the nearby Southern Cross/'''Crux'''. The Argo Navis itself is a huge asterism, made by three constellations: '''Carina''', '''Puppis''' & '''Vela'''.

The '''13''' constellations of the Zodiac make together a "ring" around the Celestial Sphere, and each is like one link of a circular chain. They are placed in the Sky with the same order we learnt when we're children: Aries the Ram, Taurus the Bull, Gemini the Twins, Cancer the Crab, Leo the Lion, Virgo the Virgin, Libra the Scales, Scorpius [[note]]NOT Scorpio: this archaic term is used only in Astrology.[[/note]] the Scorpion, (Ophiuchus the Snake-holder), Sagittarius the Archer, Capricornus [[note]]NOT Capricorn: this archaic term is used only in Astrology. [[/note]] the Sea-Goat, Aquarius the Water-Carrier, and Pisces the Fishes. However, they actually ''do not'' start with Aries and end with Pisces; like a ring-shaped chain the Zodiac has not a "start" and an "end", and you can alternatively read its constellations in the opposite direction: Pisces -- Aquarius -- Capricornus -- Sagittarius -0 Ophiuchus -- Scorpius -- Libra -- Virgo - Leo -- Cancer -- Gemini -- Taurus -- Aries. In the list below we don't follow rigidly the classical order because is more convenient so.

!THE 88 CONSTELLATIONS

The '''13''' constellations of the Zodiac make together a "ring" around the Celestial Sphere, and each is like one link of a circular chain. They are placed in the Sky with the same order we learnt when we're children: Aries the Ram, Taurus the Bull, Gemini the Twins, Cancer the Crab, Leo the Lion, Virgo the Virgin, Libra the Scales, Scorpius [[note]]NOT Scorpio: this archaic term is used only in Astrology.[[/note]] the Scorpion, (Ophiuchus the Snake-holder), Sagittarius the Archer, Capricornus [[note]]NOT Capricorn: this archaic term is used only in Astrology. [[/note]] the Sea-Goat, Aquarius the Water-Carrier, and Pisces the Fishes. However, they actually ''do not'' start with Aries and end with Pisces; like a ring-shaped chain the Zodiac has not a "start" and a "end", and you can alternatively read its constellations in the opposite direction: Pisces - Aquarius - Capricornus - Sagittarius - Ophiuchus - Scorpius - Libra - Virgo - Leo - Cancer - Gemini - Taurus - Aries. In the list below we don't follow rigidly the classical order because is more convenient so.

Recent constellations make nearly half the constellations in the Sky. The vast majority of them are in the Southern Celestial Hemisphere. All were created between the 1600s and the 1800s, either to fill the still "empty" spaces in the Sky, or by taking some stars away from other pre-existing figures. By far the most famous recent constellation is the Southern Cross, used by people living below the Equator to identify the South direction of the Earth. All the others (except four) were invented by only three astronomers: Bayer, Hevel, and Lacaille.

* '''The 14 Lacaille's Constellations.''' Lacaille was a 17th century French abbot who invented 14 new constellations in the Southern Hemisphere. [[note]] Lacaille was also the creator of Carina, Puppis & Vela, the three parts of the former Ship Argo. Since they are simple divisions of a classical constellation most astronomers do not classify them as proper Lacaille's constellations. [[/note]]Lacaille's constellations include some of the faintest and least-known figures in the whole Sky, even though three enjoy more fame: '''[[http://en.wikipedia.org/wiki/Sculptor_(constellation) Sculptor]] the [[ExactlyWhatItSaysOnTheTin Sculptor]]''' [[note]]It doesn't portray the man but only his study however.[[/note]], '''[[http://en.wikipedia.org/wiki/Fornax Fornax]] the Furnace''' [[note]] It's not a furnace but the Chemical Oven, used for scientific experiments.[[/note]], and Octans, see at the bottom for the latter. As a group, Lacaille's figures appear mixed with the Bayer's ones in the deep-south sky, even though some are more northern and placed between ancient constellations. Lacaille created them mainly to celebrate Man's creativity: unusually for constellations, they don't represent human or animal character but scientific / artistic objects. For some reason some astronomers don't belove them much, and contest their presence in the modern constellation list. They are: '''[[http://en.wikipedia.org/wiki/Antlia Antlia]] the Pneumatic Machine''', [[note]]Between Hydra and the Sails of the Ship Argo, it's an almost-invisible figure portraying a scientific instrument to create the artificial void, though it can also be visualized as a simple air-pump.[[/note]] '''[[http://en.wikipedia.org/wiki/Caelum Caelum]] the Burin''', [[note]]Between the Dove and the right bank of the Eridan River, it represents the Sculptor's Chisel. It's the constellation with the least number of stars visible to the naked eye: only 4. [[/note]] '''[[http://en.wikipedia.org/wiki/Circinus Circinus]] the Compasses''', [[note]]Pressed between Alpha Centauri and the Southern Triangle, it's the Lacaille's constellation with the smallest area, and resembles the eponymous tool to draw circles. [[/note]] '''[[http://en.wikipedia.org/wiki/Horologium_(constellation) Horologium]] the Clock''', [[note]]More precisely a Pendulum Clock, is a relatively large but almost-empty area near Achernar and the Male Sea-Snake, and is also close to the Burin above.[[/note]] '''[[http://en.wikipedia.org/wiki/Mensa_(constellation) Mensa]] the Table''', [[note]]Not an actual table but the Table-Mountain near Cape Town (South Africa), from where Lacaille made its observations of the Southern Celestial Hemisphere. The second constellation closest to the South Pole, Mensa has been quoted "the faintest constellation in the whole sky" with its brighter stars barely visible to naked eyes, but compensating this contains a small portion of the Large Magellanic Cloud (see "Dorado" above).[[/note]] '''[[http://en.wikipedia.org/wiki/Microscopium Microscopium]] the Microscope''', [[note]]Just as faint as the Table but much more northern than the latter. Between Sagittarius, Capricornus & Piscis Austrinus, some have quoted the Microscope "the most unnecessary constellation in the sky" because was created by taking its stars away from the Southern Fish's tail.[[/note]] '''[[http://en.wikipedia.org/wiki/Norma_(constellation) Norma]] the Square''', [[note]]Between the Wolf and the Altar, this tiny figure portrays a Set Square (though some call it the Ruler), and has not any Alpha star. [[/note]] '''[[http://en.wikipedia.org/wiki/Pictor Pictor]] the Painter''', [[note]]Like Sculptor it's not the human; its complete name is the Painter's Easel. Between the bright star Canopus and the Large Magellanic Cloud, one Pictor's stars (the Beta) was the first star to have revealed a possible planetary system in, the 1980s. [[/note]] '''[[http://en.wikipedia.org/wiki/Pyxis Pyxis]] the Compass''', [[note]]The most northern Lacaille's constellation, Pyxis was originally the mast of Ship Argo; now it represents the tool to find the magnetic North, and shouldn't be confused with the Compasses. Some mention Pyxis as "the forth portion of the former Argo Navis", but unlike Carina Puppis & Vela it has its own greek letters including an Alpha star.[[/note]] '''[[http://en.wikipedia.org/wiki/Reticulum Reticulum]] the Reticle''', [[note]]A small but relatively visible rhombus representing the reticle, a small "net" made of human hair Lacaille used to put on the ocular of his telescope. Pictor, Dorado, Reticulum & Horologium make together a foursome of small constellations between Canopus and Achernar.[[/note]] and '''[[http://en.wikipedia.org/wiki/Telescopium Telescopium]] the Telescope''', [[note]]Below Sagittarius and the Southern Crown and above the Peacock, it's a humble but right homage to the most important astronomical tool. Significantly, the Telescope was put by Lacaille near the Microscope. Telescopium is the biggest Lacaille's constellation after Sculptor, Fornax and Octans.[[/note]]. The Sculptor and the Furnace are placed near each other below the Whale; the Sculptor is near the bright star Fomalhaut, the Furnace is ringed by a bend of the Eridan River. They are medium-sized constellations, about as large as Canis Major or Carina, whose area is visible from the USA. Though very difficult to spot because of their faintness, both are interesting because contain several galaxies. Some are small members of our Local Group, ex. the "Fornax Dwarf" and the "Sculptor Dwarf", both only a bit more distant from the Milky Way Galaxy than the Magellanic Clouds; others pertain to distant clusters. One galaxy of the latter (in Fornax) is named the Giant Barred Spiral Galaxy: this is indeed an often-cited example of a [[ExactlyWhatItSaysOnTheTin barred spiral galaxy]], because it has only two spiral arms protruding from a central "bar". [[note]]Interestingly, it was recently hypothesized that even our Galaxy and the LMC are barred spiral galaxies, but the central bar of the Milky Way is not visible from Earth, and that of the LMC is very incospicuous. It was also very recently found (thanks to radiotelescopes) that a "phantom" dwarf galaxy, the [[http://en.wikipedia.org/wiki/Sagittarius_dwarf_elliptical_galaxy Sagittarius Dwarf]], lies at the opposite end of our Milky Way in respect to where we are, and could even be "sucked" by our own Galaxy in the future![[/note]]. The Sculptor contains the South Pole of our own Galaxy; this explain why so many distant galaxies are visible in these two constellations (like in "Coma Berenices", that contains the galactic North Pole). Let's end our trip among constellations with '''[[http://en.wikipedia.org/wiki/Octans Octans]] the Octant'''. [[note]]This was an ancient astronomical instrument very similar to the Sextant portrayed in the equatorial sky[[/note]]. This is a medium-sized but faint triangle-shaped constellation, but has a very special privilege: is ''this'' the constellation whose area contains the celestial South Pole. The Octant is slightly wider in area than Ursa Minor at the North Pole, but unlike the latter, its visible star closest to the south Pole (the Sigma) is barely visible to a naked eye.

** the '''Virgo Cluster''' of galaxies and the '''Sombrero Galaxy'''

* '''[[http://en.wikipedia.org/wiki/Centaurus Centaurus]]: the Centaur.''' The other celestial centaur other than Sagittarius, Centaurus can be considered the southern counterpart of the Great Bear. It's the biggest entirely-southern constellation (after Eridanus, which barely touches the Equator), and is at the same time one of the brightest, just like the Bear in the Northern Hemisphere. The Centaur has a complex shape; only the "head" and the human torso of the creature are well-visible from most of the USA during the spring. The Centaur's two main stars are among the most luminous in the firmament and portray its front feet, but since are in the southern extremity of the constellation, they are visible from the most southern USA only. Curiously, both [[IHaveManyNames are commonly-known with more than one name:]] Alpha Centauri is also called Rigil Kentaurus or Toliman; Beta Centauri is also Hadar or Agena. Beta is a blue star, while Alpha is yellow; since they appear near the Southern Cross, they aid the latter to find the South Pole. Despite its name, Omega Centauri is not a star: it is the brightest Globular Cluster in the sky, even more than the one visible in Hercules, but is visible to the naked eye as an inconspicuous starlet. Also famous is a giant elliptical galaxy outside our Local Group called "Centaurus-A", which shows a dark stripe at its equator and emits powerful radio signals. These peculiar characteristics are due to the collision of Centaurus-A with a smaller spiral galaxy. [[note]]Collisions of galaxies are not so rare as one might think: galaxies are relatively close to each other within a "cluster", and when colliding they emit powerful radiations detectable from Earth. However, since galaxies are not solid bodies they actually fuse each other when "colliding". Moreover, since a galaxy is mainly made of dust and gas, no one of its stars will probably get destroyed in the process.[[/note]]

* '''[[http://en.wikipedia.org/wiki/Eridanus_(constellation) Eridanus]]: the Eridan River.''' The Eridan River rivals Hydra the Sea-Snake for the title of "the longest constellation in the sky". It's a sort of enormously-vast "inverted S" made of faint stars, whose "spring" is just below the Equator near Rigel (one of Orion's feet), while its "mouth" is not far from the South Pole. If it represents a RealLife river or a legendary one is uncertain. The only bright star of the River is just in its mouth: Achernar, the 9th brightest star in the firmament. This is a bluish star placed at the opposite end of the South Pole with regard to the Alpha-Beta Centauri couple; as the Pole is in the middle between Achernar and the latter, Achernar can help southern observers to better-find the pole itself. Even though this star is not visible from the northern USA, most of the river goes above the U.S. horizon in winter times. Eridanus contains also other two interesting stars: "Epsilon Eridani" (a close star similar to the Sun which is surrounded by a planetary system), and "40 Eridani" (a triple star whose smallest members are a red dwarf and a white dwarf). [[note]]Here is a list of the eight stars closest to us nowadays: '''1)''' Proxima Centauri; '''2)''' Alpha Centauri A; '''3)''' Alpha Centauri B; '''4)''' The Barnard's Star (in Ophiuchus); '''5)''' Wolf 359 (in Leo); '''6)''' Lalande 21185 (in Ursa Major); '''7)''' Sirius A (the main Dog's Star); '''8)''' Sirius B (the "white dwarf" companion of Sirius A). Six of them are dwarf stars ("red dwarfs" except for Sirius B), all so faint they are invisible to a naked eye. On the other hand, both Alpha Centauri A and Sirius A are slightly bigger and brighter than the Sun; their inherent luminosity and their closeness to us make them appearing the third and the first brightest stars in our sky.[[/note]]

* '''[[http://en.wikipedia.org/wiki/Hercules_(constellation) Hercules]]: the Knelt Man.''' The second largest constellation above the sky Equator after the Great Bear (and the 5th biggest of the whole Sky), Hercules would be visible between Arcturus and Vega in the summer sky, but its stars are all rather faint and the vast figure is not easy to see from cities. Represents the famous Greek hero in a kneeled pose, with one foot near the Dragon's head; several other ancient constellations are somehow linked to the hefty man by some legends. Hercules' head is marked by a "red giant" star, while his body is partially signed by a quadrilateral of stars just in the middle of his figure, nicknamed "the Keystone". In one side of the Keystone there is a famous deep-sky object: [[note]]Deep-Sky Objects are nebulae, galaxies & star-clusters considered together. In other words: if it's neither a proper star nor a body of our Solar System, then is a deep-sky object.[[/note]] "M13", the greatest "globular cluster" in the Northern Sky. [[note]] Globular Clusters are huge spherical clusters containing millions of stars. They have nothing to do with the much smaller "open" star clusters: the globulars are ''outside'' the disk of our Galaxy, encircling it together like an imaginary sphere called "the Galaxy's Halo". Also note the stars of a Globular Cluster are much more ancient than those of the Open Clusters.[[/note]] Deep-sky objects have their own terminology; the most important ones are listed in the Messier Catalogue or M-Catalogue, which contains about 110 objects from the whole firmament. M13 is the 13th object in the list. Finally, one curiosity: our Solar System is traveling in the space toward the celestial area occupied by Hercules.

* '''[[http://en.wikipedia.org/wiki/Pegasus_(constellation) Pegasus]] & [[http://en.wikipedia.org/wiki/Andromeda_(constellation) Andromeda]]: the Winged Horse and the Chained Woman.''' The names of these two constellations are rather familiar though for different reasons. Like Auriga & Taurus above their stars actually make one single figure in the sky, and one star appears shared by both. Modern astronomers, however, assign this star to Andromeda. Despite their lacking of 1° magnitude stars, Pegasus and Andromeda make together the brightest figure of the Northern Fall. Pegasus portrays the famous [[MixAndMatchCritter flying horse with bird-like wings]], and is the third biggest constellation entirely in the sky's Northern Hemisphere. Its most evident feature is the so-called "Great Square" (actually a rectangle) of stars signing the animal's body. [[note]] But only three really belong to the Horse; the forth one marks also the Woman's head, and is the disputed star today attributed to Andromeda.[[/note]]. The horse's head and forelegs are marked by other stars, while the hindquarters curiously are not shown in drawings. Andromeda is basically a curved "tail" of stars (with other fainter stars around) protruding from the Great Pegasus' Square; it portrays the woman chained against a rock (see Perseus to understand why). The fame of Andromeda is strictly linked to one single deep-sky object: the Great Andromeda's Galaxy, also called "The Andromeda Galaxy" or simply "Andromeda". This is the biggest galaxy within our Local Group of galaxies, a bit larger than our own Galaxy but very similar to the latter: both share the classic spiral shape and both have two smaller "dwarf galaxies" nearby. In the Messier Catalogue the Andromeda Galaxy is the 31st object (M31) and is the more distant celestial object still visible with naked eyes: 2,000,000 light-years from us.

* '''[[http://en.wikipedia.org/wiki/Hercules_(constellation) Hercules]]: the Knelt Man.''' The second largest constellation above the sky Equator after the Great Bear, Hercules would be visible between Arcturus and Vega in the summer sky, but its stars are all rather faint and the vast figure is not easy to see from cities. Represents the famous Greek hero in a kneeled pose, with one foot near the Dragon's head; several other ancient constellations are somehow linked to the hefty man by some legends. Hercules' head is marked by a "red giant" star, while his body is partially signed by a quadrilateral of stars just in the middle of his figure, nicknamed "the Keystone". In one side of the Keystone there is a famous deep-sky object: [[note]]Deep-Sky Objects are nebulae, galaxies & star-clusters considered together. In other words: if it's neither a proper star nor a body of our Solar System, then is a deep-sky object.[[/note]] "M13", the greatest "globular cluster" in the Northern Sky. [[note]] Globular Clusters are huge spherical clusters containing millions of stars. They have nothing to do with the much smaller "open" star clusters: the globulars are ''outside'' the disk of our Galaxy, encircling it together like an imaginary sphere called "the Galaxy's Halo". Also note the stars of a Globular Cluster are much more ancient than those of the Open Clusters.[[/note]] Deep-sky objects have their own terminology; the most important ones are listed in the Messier Catalogue or M-Catalogue, which contains about 110 objects from the whole firmament. M13 is the 13th object in the list. Finally, one curiosity: our Solar System is traveling in the space toward the celestial area occupied by Hercules.

* '''[[http://en.wikipedia.org/wiki/Draco_(constellation) Draco]]: the Dragon.''' Like the Great Bear, the Dragon is one of the biggest constellations in the Sky. It's a sort of large "inverted S" which signs the snake-like body of a mythical dragon; its head is marked by a small quadrilateral at one end of the "S". Unlike the Great Bear, the Dragon is faint and difficult to recognize; it is higher in the sky in Summer, and would be visible next to the the Little Bear -- while the dragon's tail wedges between the two bears. The Dragon's Alpha star (unusually, not the brightest star of its own constellation, the Gamma is) was in ancient times the Polar Star because of the [[http://en.wikipedia.org/wiki/Precession Precession]]; the modern Polar Star has owed this privilege only since about 500 years. The next 20,000 years the Polar would be Vega, in the Lyre. Draco has also included the north pole of the Ecliptic -- for the record, the Ecliptic is the circular route covered by the Sun during its apparent yearly "trip" in the firmament, but see the "Zodiac" section to learn better. In the opposite side of the circumpolar area there is another constellation, the Giraffe; but this one is not described here (see "recent constellations" below).

** If you live in the Earth's Northern Hemisphere Orion is a winter constellation. Even though is called "the Hunter", its portrayal looks more like a warrior seen from the front. Orion is shown lifting a mace and a shield (both signed by faint stars) to defend himself against the charging Bull nearby, and has also a sword hanging from his belt. The belt is signed by the aforementioned three central stars, and is just on the celestial equator; the shoulders and the feet are symmetrically placed above and below the equator, and are signed by the stars of the "rectangle". Orion's right shoulder and his left foot are marked by two of the brightest stars in the Sky: Betelgeuse & Rigel, [[note]] Both are Arabic words meaning [[ExactlyWhatItSaysOnTheTin shoulder]] and [[ExactlyWhatItSaysOnTheTin foot]] respectively.[[/note]] both hundreds of light-years far from us. Rigel has the letter "Beta" and thus should be less-luminous than Betelgeuse (the "Alpha" star); actually Rigel is brighter than Betelgeuse, and the 7th brightest in the whole firmament -- however, note that Betelgeuse slightly changes its luminosity periodically, and can be the brightest star in certain moments. Making their constellation even more attractive, the two stars have contrasting colors: Rigel is blue, Betelgeuse is red. Both belong to the "super-giant stars" category, being even bigger than "simply-giants" like Arcturus. Rigel's diameter is about 80 times greater than the Sun's; if placed at the center of the Solar System, Rigel would swallow Mercury in its orbit. But even Rigel is a tennis-table ball when compared with Betelgeuse. This star has a diameter 1000 times greater than the Sun, and is one of the biggest stars in the whole Galaxy; if put in the place of the Sun, Betelgeuse would swallow the whole Inner Solar-System -- Mercury, Venus, Earth, Mars, the Asteroid Belt, and maybe even Jupiter!! Among the stars known since antiquity, Betelgeuse is arguably the biggest. In other world, Betelgeuse could contain 10,000,000 Suns inside it. [[note]]Remember that the Sun could contain about 10,000 Earths, giving an effective idea about how immense the stars can be.[[/note]] Astonishingly, Betelgeuse's total mass is only 50-80 times the Sun. This means its density is extremely low: an amount of Betelgeuse's matter as big as a house would weigh like a sand-grain on Earth. Moreover, being a red star, the surface of Betelgeuse is colder than the yellow Sun and much colder than the blue Rigel. Despite its smaller diameter, Rigel has about the same total mass of Betelgeuse and produces even more light than the latter; one day Rigel will become a red super-giant the size of Betelgeuse. Both Rigel and Betelgeuse are super-massive stars at the end of their life, with Betelgeuse in a more-advanced phase than Rigel (as recently as TheNewTwenties Betelgeuse has changed noticeably its brightness, and some speculate that it could explode soon becoming a spectacular Supernova as bright as a half-Moon!). When born with a mass much bigger than the Sun, stars only live few million years (Rigel & Betelgeuse were still non-existing when the dinosaurs populated the Earth!). After ending their internal "fuel" of hydrogen they become enormously inflated, and finally explode with unimaginable violence (the Supernova). All what remains from the former super-giant is a "pulsar" or even a Black Hole -- to learn more, see Taurus in the Zodiac section and the Useful Notes about UsefulNotes/BlackHoles.

** If you live in the Earth's Northern Hemisphere Orion is a winter constellation. Even though is called "the Hunter", its portrayal looks more like a warrior seen from the front. Orion is shown lifting a mace and a shield (both signed by faint stars) to defend himself against the charging Bull nearby, and has also a sword hanging from his belt. The belt is signed by the aforementioned three central stars, and is just on the celestial equator; the shoulders and the feet are symmetrically placed above and below the equator, and are signed by the stars of the "rectangle". Orion's right shoulder and his left foot are marked by two of the brightest stars in the Sky: Betelgeuse & Rigel, [[note]] Both are Arabic words meaning [[ExactlyWhatItSaysOnTheTin shoulder]] and [[ExactlyWhatItSaysOnTheTin foot]] respectively.[[/note]] both hundreds of light-years far from us. Rigel has the letter "Beta" and thus should be less-luminous than Betelgeuse (the "Alpha" star); actually Rigel is brighter than Betelgeuse, and the 7th brightest in the whole firmament. [[note]]However, note that Betelgeuse slightly changes its luminosity periodically, and can be the brightest star in certain moments.[[/note]]. Making their constellation even more attractive, the two stars have contrasting colors: Rigel is blue, Betelgeuse is red. Both belong to the "super-giant stars" category, being even bigger than "simply-giants" like Arcturus. Rigel's diameter is about 80 times greater than the Sun's; if placed at the center of the Solar System, Rigel would swallow Mercury in its orbit. But even Rigel is a tennis-table ball when compared with Betelgeuse. This star has a diameter 1000 times greater than the Sun, and is one of the biggest stars in the whole Galaxy; if put in the place of the Sun, Betelgeuse would swallow the whole Inner Solar-System -- Mercury, Venus, Earth, Mars, the Asteroid Belt, and maybe even Jupiter![[note]]Among the stars known since antiquity, Betelgeuse is arguably the biggest.[[/note]] In other world, Betelgeuse could contain 10,000,000 Suns inside it. [[note]]Remember that the Sun could contain about 10,000 Earths, giving an effective idea about how immense the stars can be.[[/note]] Astonishingly, Betelgeuse's total mass is only 50-80 times the Sun. This means its density is extremely low: an amount of Betelgeuse's matter as big as a house would weigh like a sand-grain on Earth. Moreover, being a red star, the surface of Betelgeuse is colder than the yellow Sun and much colder than the blue Rigel. Despite its smaller diameter, Rigel has about the same total mass of Betelgeuse and produces even more light than the latter; one day Rigel will become a red super-giant the size of Betelgeuse. Both Rigel and Betelgeuse are super-massive stars at the end of their life, with Betelgeuse in a more-advanced phase than Rigel. When born with a mass much bigger than the Sun, stars only live few million years (Rigel & Betelgeuse were still non-existing when the dinosaurs populated the Earth!). After ending their internal "fuel" of hydrogen they become enormously inflated, and finally explode with unimaginable violence (the Supernova). All what remains from the former super-giant is a "pulsar" or even a Black Hole. [[note]] To learn more, see Taurus in the Zodiac section and the Useful Notes about UsefulNotes/BlackHoles.[[/note]]

** '''The Orion's Shield''': Out of the Orion's Rectangle, it's made by faint stars in a ")" shape pointing rightwards toward Taurus. The Orion's Mace is also made by faint stars outside the rectangle, is placed leftwards and is lifted by him in the direction of Gemini.

* '''[[http://en.wikipedia.org/wiki/Hydra_(constellation) Hydra]]: the Sea Snake.''' Some vast constellations appear like a very long line of faint stars meandering among other more solid figures, often with a group of stars which mark one end of the line. Draco is a good example near the North Pole; others are Pisces and Serpens. However, the two UpToEleven examples are better-visible from the Southern Hemisphere: Eridanus the River (see below) and Hydra the Sea-Snake. [[note]]Also called with the weird name "the Female Sea-Snake" to distinguish it from the [[TheUnfairSex much humbler]] Hydrus, the "male" sea-snake near the South Pole.[[/note]] Theoretically, Hydra should be the mythical seven-headed monster defeated by Hercules during one of his 12 challenges, but is always portrayed as an one-headed snake. Although less-known than other celestial figures because of its indistinct appearance, the Sea-Snake detains the special record of the largest by area among all 88 constellations in the Sky. Its head is marked by a small bunch of stars near the Crab just above the celestial Equator; the remaining body is below the equator, traveling between Leo/Virgo and the Centaur and ending near the Scales. Though mainly visible in the northern Spring, the Sea-Snake's head is already visible in Winter and its tail still in Summer, giving an idea about its extreme length.

*** Taurus contains another singular object. This one is even more recent than the Pleiades, appeared in the sky ''in full Human History'': M1, the Crab Nebula, the first object in the Messier's list, and definitively one of the most portrayed celestial objects in astronomy books and magazines today. Ironically, the "crab nebula" is invisible to a naked eye and its shape actually recalls anything but a crab. M1 is the most well-known example of a remain of Supernova. As said above Supernovas are super-giant stars exploding in the space. [[note]] Some scientists formerly thought a Supernova could have been the cause of the Dinosaur Extinction 65 million years ago. Its radiations would have reached the Earth provoking genetic mutations in the living beings, exterminating them and finally leading dinosaurs to their extinction. However, there is not proof about all this, and this theory is now discarded in favor of the asteroid/comet impact one. See also [[UsefulNotes/{{Dinosaurs}} here]].[[/note]] The astonishing this is, when the explosion happens the star emits such an immense amount of light it can even ''outshine its own whole galaxy!'' If a Supernova explodes within our Galaxy, it can appear so luminous in our sky to project shadows (just like it was another Moon). This is what really happened in year 1054, when Chinese and Native-American observers reported an entirely "new" star of extreme brightness in the sky; it was indeed what modern astronomers call a Supernova (literally "super-new"). [[note]] Some sources say it became [[UpToEleven as bright as the Sun or even more]], but this is not the case. Oddly, European observers of the Medieval Age didn't report the event. If it was really like a second Sun, it would not get unnoticed to medieval people![[/note]] If we are living before 1054 we'd not see the Crab Nebula, but its original star instead. Today, what remains from the former super-giant star is the nebula itself (whose gas is constantly dispersing in the space and will become invisible in the future), and a strange object inside it, infinitively smaller than the original star but even more impressive than a White Dwarf: a Pulsar, a kind of "neutron star". [[note]]To be precise, the Pulsar is not a proper star but a middle-way between a White-Dwarf Star and a Black-Hole. It's much smaller than the Earth itself but even more dense than a "white dwarf". Here the matter is not made of the usual atoms but only of an extremely-concentrated mass of Neutrons -- hence "neutron star". The pulsar spin more times per second like a spinning-top, and emit at each turn a burst of X-rays and Gamma-rays detectable from Earth like a lighthouse -- hence "Pulsar", which is a {{Portmanteau}} of "Puls(ating) (st)ar". Many other Pulsars are known in our Galaxy, usually originated from a Super-Nova: for example the one of the Veil Nebula in the Swan, and "Cassiopeia A" in the Queen. The latest one is the remain of the last supernova exploded in our Galaxy (1500 century), but the event was only barely seen to the naked eye. [[/note]]

* '''"Argo Navis": the Ship Argo.''' Originally, the legendary ship of the Argonauts was one single constellation in the Southern Hemisphere. Between the Centaur and the Great Dog, Argo Navis was by far the biggest constellation in the Sky; but in the 1700 century one astronomer (Lacaille) thought it was really too large and divided it in three distinct constellations: '''Carina''' the Keel, '''Puppis''' the Stern, and '''Vela''' the Sails (all described in the next folder), each of them is still larger than most other constellations below the Equator. Before the division, however, the usual Greek letters have already been assigned to the whole Ship Argo. As a consequence, the stars of each of the three portions of the ship has only some greek letters and not others. For example, both the Sails and the Stern haven't any Alpha star. Just for the record, the letters of the greek alphabet are: ''Alpha, Beta, Gamma, Delta, Epsilon, Zeta, Eta, Theta, Iota, Kappa, Lambda, Mu, Nu, Xi, Omicron, Pi, Rho, Sigma, Tau, Upsilon, Phi, Chi, Psi,'' and ''Omega''.

Recent constellations make nearly half the constellations in the Sky. The vast majority of them are in the Southern Celestial Hemisphere. All were created between the 1500 and the 1700 century, either to fill the still "empty" spaces in the Sky, or by taking some stars away from other pre-existing figures. By far the most famous recent constellation is the Southern Cross, used by people living below the Equator to identify the South direction of the Earth. All the others (except four) were invented by only three astronomers: Bayer, Hevel, and Lacaille.

* '''[[http://en.wikipedia.org/wiki/Puppis Puppis]] & [[http://en.wikipedia.org/wiki/Vela_(constellation) Vela]]: the Stern and the Sails of the Ship Argo.''' These parts of the former Ship Argo are less luminous than the Keel but more northern, thus easier to spot from the USA. The Stern is a long irregular constellation visible in winter between Sirius and Canopus; the Sails is another irregular figure similar to a polygon, but is better-visible in Spring. If we could see the whole "ship", Vela would appear just above Carina. Two stars of the Sails and two of the Keel form together the so-called "False Cross", a small quadrilateral deceptively similar to the true Southern Cross. However, being the false cross larger fainter & farther from Alpha/Beta Centauri than the true cross, it's easily unmasked. As said above, both the Stern and the Sails lack the Alpha star. The Stern's main star (the Zeta) is one of the bluest and hottest known stars; the Sails' main star (the Gamma) is even more peculiar, as it has lost its external shell. Both constellations are crossed by the Milky Way; the Stern includes several Open Clusters, while the Sails contains a huge but faint nebula with a rest of a Super-Nova inside. Beside Puppis you could see another smaller and fainter recent constellation: '''[[http://en.wikipedia.org/wiki/Columba_(constellation) Columba]] the Dove'''. Created at the end of the 1500 century, this is maybe the only constellation in the sky to portray a Christian figure, the Great Deluge-related Noah's Dove. If so, the Ship Argo could be [[AlternativeCharacterInterpretation alternatively]] considered the Noah's Ark.

* '''[[http://en.wikipedia.org/wiki/Camelopardalis Camelopardalis]] & [[http://en.wikipedia.org/wiki/Monoceros Monoceros]]: the Giraffe and the Unicorn.''' These two constellations (plus Columba above and Coma Berenices below) were created by some astronomers who weren't neither Bayer nor Hevel nor Lacaille. All them were invented in the 1500 century -- about the same years of the Bayer's constellations but before the Hevel's and Lacaille's ones. Both Camelopardalis and Monoceros were ideated by the same person, and portray two similar figure: a giraffe (once called "camelopard") and an unicorn (the legendary [[MixAndMatchCritter one-horned horse]]). [[note]]In the 1500 century the African big fauna was not as familiar to european people as is today; a critter like the giraffe could easily be passed off as something mythical, like an unicorn.[[/note]] Camelopardalis the Giraffe is one of the six constellations closest to the North Pole, together with the Dragon, the two Bears, the King, and the Queen; but is by far the faintest of them, to the point it is hardly visible even when we're far from city lights. The Giraffe is nonetheless the largest recent constellation, well-filling the apparently "empty" area between the two Bears, Perseus, and Auriga. On the other hand, Monoceros the Unicorn is equatorial; it's the space apparently devoid of stars between Orion and his two Dogs. In spite of being easily overshadowed by the Hunter, the Unicorn is crossed by the Milky Way and contains two interesting nebulae, the Rosette Nebula similar to a flower, and the dark Cone Nebula.

* '''The 7 Hevelius' Constellations.''' Polish astronomer John Hevel (Hevelius in latin) [[note]]In the 1600 Europe there was still the habit of "latinizing" the names of important people.[[/note]] invented at the end of the 1600 century seven new constellations in the Northern and Equatorial sky. Before this, another astronomer had already invented another figure, '''[[http://en.wikipedia.org/wiki/Coma_Berenices Coma Berenices]]''' (which is here for convenience). This oddly-named constellation (literally "'''Berenices' Hair'''") is one of the weakest constellations of the Northern Sky, and portrays the cut hair of an ancient Egyptian queen. Between the Herdsman, the Lion & Virgin, the Coma is nonetheless interesting because some galaxies of the Virgo Cluster are actually visible in this constellation. Coma Berenices also contains the North Pole of our Galaxy. [[note]]that is, the perpendicular point with regard to the Milky Way's plan. In this area distant galaxies are easier to see than near the Milky Way, being not "darkened" by the dusts of the latter.[[/note]] The seven Hevel's constellations are very faint as well, but usually portray RealLife animals. One of the most notable is '''[[http://en.wikipedia.org/wiki/Canes_Venatici Canes Venatici]] the Hounds'''. Between the Great Bear, the Herdsman & and the Berenice's Hair, it is apparently made by only two stars, Alpha & Beta, [[note]]Curiously, many Hevel's constellations have only one or two stars labeled with a greek letter.[[/note]], each portraying one of the Herdsman's two hunting dogs. However, the Alpha is also dedicated to the english king Karol 1th, and named Cor Caroli ("Karol's Heart"). The Hounds or Hunting Dogs contain also one of the most famous galaxies outside the Local Group: the Whirlpool Galaxy, the first ever galaxy whose spiral shape has been revealed with the telescopes (1800 century). Hevelius also invented '''[[http://en.wikipedia.org/wiki/Lynx_(constellation) Lynx]] the [[ExactlyWhatItSaysOnTheTin Lynx]]''' to fill the "empty" space between the Great Bear, the Twins and the Coachman or Charioteer; it's said he called it with this name because "only lynx-eyed people can glimpse it"! This is the largest Hevel's constellation but has only one star with a greek letter (the Alpha). Even though mainly visible in Winter, Lynx is placed very north in the Sky, and could at high latitudes be visible all year round. Near the lynx there is another celestial cat invented by Hevel, but even less conspicuous: '''[[http://en.wikipedia.org/wiki/Leo_Minor Leo Minor]] the Little Lion''' portays either a lion cub or an undersized adult male lion, between the Great Bear's paws and the more familiar Lion's head. The Little Lion's only star with a Greek letter is, oddly, the Beta. Between the Swan and the Eagle, other than the Arrow you could also "see" '''[[http://en.wikipedia.org/wiki/Vulpecula Vulpecula]] the Little Fox''' (or more simply the Fox); [[note]] Once called "Vulpecula com Anser", the Little Fox with Goose; old portrayals show the fox holding a dead goose with its mouth.[[/note]] actually its stars are so faint, the constellation is almost invisible to a naked eye. Nonetheless, the Fox interests night-sky observers because contains two notable objects: the Dumbbell Nebula (perhaps the easiest planetary nebula to see from Earth), and the Coathanger -- a small group of starlets visible with binoculars, that ''really'' resembles the eponymous thing. Between the Swan and the Winged Horse there is '''[[http://en.wikipedia.org/wiki/Lacerta Lacerta]] the Lizard''', a bunch of stars which are very north in the sky like those of the Lynx. However, this figure was originally conceived as the "Scepter and Hand of Justice" before becoming the Lizard. Just below the Equator is '''[[http://en.wikipedia.org/wiki/Scutum_(constellation) Scutum]] the Shield''' [[note]] More precisely the Sobieski's Shield: John Sobieski was the Polish king at Hevel's times.[[/note]], another tiny inconspicuous constellation crossed by the Milky Way, near the Eagle and the Snake's Tail, which contains an open cluster named "wild ducks" and a notable variable star, Delta Scuti. Finally, '''[[http://en.wikipedia.org/wiki/Sextans Sextans]] the Sextant''', an almost-invisible Equatorial constellation between the Lion and Hydra: a poor homage to the sextant, one of the most important astronomical instruments in the past -- but sometimes home for the Moon and some planets because of its closeness to the Ecliptic.

* '''The 12 Bayer's Constellations.''' Johann Bayer was the German astronomer who invented in the 1600 century the usage to list the stars in a constellation with Greek letters. He also added 12 new constellations in his Atlas to fill the still-empty-at-the-time deep southern Sky (even though they were already invented by other colleagues in the 1500 century). Most Bayer's figures are small and faint, and many are too close to the South Pole to be spotted from the USA; nonetheless, they are generally brighter and more recognizable than those invented by Lacaille (see below). Unlike the latter, Bayer's constellations usually represent exotic RealLife animals (which were at the time compared to the mythical beasts portrayed in the classical constellations). Five are birds: '''[[http://en.wikipedia.org/wiki/Grus_(constellation) Grus]] the Crane''', [[note]]This is the brightest and most northern Bayer's constellation, just below the luminous star Fomalhaut (in the Southern Fish). The Crane's shape resembles a bit a miniature Swan but more irregular.[[/note]] '''[[http://en.wikipedia.org/wiki/Phoenix_(constellation) Phoenix]] the Phenix''', [[note]]The only Bayer's constellation to portray a mythical critter -- the famous bird which periodically reborn from its own ashes. Phoenix is an irregular but relatively bright figure between Grus and the luminous star Achernar (signing the mouth of the Eridan River).[[/note]] '''[[http://en.wikipedia.org/wiki/Pavo_(constellation) Pavo]] the Peacock''', [[note]]Closer to the South Pole than Grus and Phoenix, it's a relatively large constellation made of an ellipse of faint stars, plus another star brighter than the others which the Royal Air Force (which required proper names for stars used in aerial navigation) [[DepartmentOfRedundancyDepartment also named Peacock]].[[/note]] '''[[http://en.wikipedia.org/wiki/Tucana Tucana]] the Toucan''', [[note]]A faint figure not far from the celestial South Pole. Being close to each other, Grus, Phoenix, Pavo & Tucana are sometimes nicknamed "the Southern Birds".[[/note]] and '''[[http://en.wikipedia.org/wiki/Apus Apus]] the Bird-of-Paradise'''. [[note]] One of the smallest and weakest Bayer's constellations, extremely close to the South Pole. Curiously, Apus means "feet-less" but the RealLife Bird-of-Paradise actually does have the feet![[/note]] Two are reptiles: '''[[http://en.wikipedia.org/wiki/Hydrus Hydrus]] the Male Sea-Snake''', [[note]]A smallish triangle between Achernar and the South Pole, it should better named the Southern sea-snake. Hydrus is not the husband of Hydra, the "female" sea-snake: the former actually indicates a real creature (a small tropical water snake), while Hydra represents a huge legendary monster.[[/note]] and '''[[http://en.wikipedia.org/wiki/Chamaeleon Chamaeleon]] the Chameleon'''. [[note]] Just a stone's throw from the South Pole, the chameleon is an elongated inconspicuous figure, but is nonetheless used sometimes to aid the finding of the Pole itself.[[/note]] Two are fish: '''[[http://en.wikipedia.org/wiki/Dorado Dorado]] the Golden Fish''', [[note]]A small elongated figure between Canopus and Achernar, Dorado does not portray the household goldfish but a large marine fish, the Coryphenid or "dolphinfish". However, some identify Dorado with a Swordfish.[[/note]] and '''[[http://en.wikipedia.org/wiki/Volans Volans]] the Flying Fish'''. [[note]]Another small faint figure near the other Bayer's fish. In the sky Volans is shown "flying" against the Ship Argo to escape Dorado; in RealLife the coryphenid actually chases flying-fishes, even when they're gliding out of water.[[/note]] Finally, one is an insect: '''[[http://en.wikipedia.org/wiki/Musca Musca]] the Fly'''. [[note]] Although very small this constellation is relatively easy to find because is adjacent to the Southern Cross (a small part of the former's "Coal Sack" trespasses in Musca). However, the Fly was originally portrayed by Bayer as a bee, named Apis ("bee" in Latin). [[/note]] The remaining two are '''[[http://en.wikipedia.org/wiki/Indus_(constellation) Indus]] the Indian''' [[note]]The only recent constellation showing a human figure, precisely a Native North American. Between the Crane, the Peacock & the Toucan, the Indian is quite indistinct but contains a near star very similar to the Sun, the Epsilon.[[/note]] and '''[[http://en.wikipedia.org/wiki/Triangulum_Australe Triangulum Australe]] the Southern Triangle'''. [[note]]The smallest Bayer's figure but with the longest Latin name of all the 88 constellations. Between Alpha Centauri and the Peacock, this is the southern counterpart of Triangulum. Both triangles are very small figures, but the Southern one is brighter and more regular.[[/note]]. Dorado and Tucana are the most interesting among all them. Each contains one of the two main small galaxies "satellites" of our own Galaxy: the so-called "Magellanic Clouds". [[note]]Portuguese navigator Magellan saw them when traveling below the Equator, and was the first to report them to the western world.[[/note]] The Large Magellanic Cloud or LMC is mainly in Dorado; the Small Magellanic Cloud or SMC is completely included in the Toucan. Hydrus (the "male sea-snake") appears between them. Unusual for galaxies, the Magellanic Clouds are perfectly visible to a naked eye, like the Great Andromeda Galaxy: these are the three non-Milky-Way galaxies visible without binoculars or telescopes. The LMC and the SMC are named so because appear like faint "clouds" near the Milky Way stripe. They actually are two "dwarf galaxies" very close to our Milky Way Galaxy, and are about 180,000 light-years from us -- much closer than every other galaxy of the Local Group except for the recently-found Sagittarius Dwarf Galaxy or SDG, see below. Both "clouds" are traditionally classified as "irregular" galaxies because they lack a precise shape, and are mainly made of young stars, gas & dust like the external disk of our own Galaxy. The LMC contains also a nebula called Tarantula Nebula (much larger than the Great Orion's Nebula, and one of the biggest known nebulas so far) for its -- allegedly for some -- spider-like shape. One star near this huge nebula exploded in year 1987 as a Supernova: it has been the ''only'' supernova seen with naked eyes since the telescope was invented by Galileo in the 1600 century. In the Tucana there is also "47 Tucanae", the second brightest Globular Cluster in the Sky after Omega Centauri: both are visible to a naked eyes like they're faint stars. Even though seems close to the SMC, 47 Tucanae actually belongs to our own Galaxy. Pavo as well contains a globular cluster, the forth most brilliant of the Sky, other to several other objects. Both globular clusters are brighter than the famous M13 in Hercules.

* '''The 14 Lacaille's Constellations.''' Lacaille was a French abbey who invented in the 1700 century 14 new constellations in the Southern Hemisphere. [[note]] Lacaille was also the creator of Carina, Puppis & Vela, the three parts of the former Ship Argo. Since they are simple divisions of a classical constellation most astronomers do not classify them as proper Lacaille's constellations. [[/note]]Lacaille's constellations include some of the faintest and least-known figures in the whole Sky, even though three enjoy more fame: '''[[http://en.wikipedia.org/wiki/Sculptor_(constellation) Sculptor]] the [[ExactlyWhatItSaysOnTheTin Sculptor]]''' [[note]]It doesn't portray the man but only his study however.[[/note]], '''[[http://en.wikipedia.org/wiki/Fornax Fornax]] the Furnace''' [[note]] It's not a furnace but the Chemical Oven, used for scientific experiments.[[/note]], and Octans, see at the bottom for the latter. As a group, Lacaille's figures appear mixed with the Bayer's ones in the deep-south sky, even though some are more northern and placed between ancient constellations. Lacaille created them mainly to celebrate Man's creativity: unusually for constellations, they don't represent human or animal character but scientific / artistic objects. For some reason some astronomers don't belove them much, and contest their presence in the modern constellation list. They are: '''[[http://en.wikipedia.org/wiki/Antlia Antlia]] the Pneumatic Machine''', [[note]]Between Hydra and the Sails of the Ship Argo, it's an almost-invisible figure portraying a scientific instrument to create the artificial void, though it can also be visualized as a simple air-pump.[[/note]] '''[[http://en.wikipedia.org/wiki/Caelum Caelum]] the Burin''', [[note]]Between the Dove and the right bank of the Eridan River, it represents the Sculptor's Chisel. It's the constellation with the least number of stars visible to the naked eye: only 4. [[/note]] '''[[http://en.wikipedia.org/wiki/Circinus Circinus]] the Compasses''', [[note]]Pressed between Alpha Centauri and the Southern Triangle, it's the Lacaille's constellation with the smallest area, and resembles the eponymous tool to draw circles. [[/note]] '''[[http://en.wikipedia.org/wiki/Horologium_(constellation) Horologium]] the Clock''', [[note]]More precisely a Pendulum Clock, is a relatively large but almost-empty area near Achernar and the Male Sea-Snake, and is also close to the Burin above.[[/note]] '''[[http://en.wikipedia.org/wiki/Mensa_(constellation) Mensa]] the Table''', [[note]]Not an actual table but the Table-Mountain near Cape Town (South Africa), from where Lacaille made its observations of the Southern Celestial Hemisphere. The second constellation closest to the South Pole, Mensa has been quoted "the faintest constellation in the whole sky" with its brighter stars barely visible to naked eyes, but compensating this contains a small portion of the Large Magellanic Cloud (see "Dorado" above).[[/note]] '''[[http://en.wikipedia.org/wiki/Microscopium Microscopium]] the Microscope''', [[note]]Just as faint as the Table but much more northern than the latter. Between Sagittarius, Capricornus & Piscis Austrinus, some have quoted the Microscope "the most unnecessary constellation in the sky" because was created by taking its stars away from the Southern Fish's tail.[[/note]] '''[[http://en.wikipedia.org/wiki/Norma_(constellation) Norma]] the Square''', [[note]]Between the Wolf and the Altar, this tiny figure portrays a Set Square (though some call it the Ruler), and has not any Alpha star. [[/note]] '''[[http://en.wikipedia.org/wiki/Pictor Pictor]] the Painter''', [[note]]Like Sculptor it's not the human; its complete name is the Painter's Easel. Between the bright star Canopus and the Large Magellanic Cloud, one Pictor's stars (the Beta) was the first star to have revealed a possible planetary system in, the 1980s. [[/note]] '''[[http://en.wikipedia.org/wiki/Pyxis Pyxis]] the Compass''', [[note]]The most northern Lacaille's constellation, Pyxis was originally the mast of Ship Argo; now it represents the tool to find the magnetic North, and shouldn't be confused with the Compasses. Some mention Pyxis as "the forth portion of the former Argo Navis", but unlike Carina Puppis & Vela it has its own greek letters including an Alpha star.[[/note]] '''[[http://en.wikipedia.org/wiki/Reticulum Reticulum]] the Reticle''', [[note]]A small but relatively visible rhombus representing the reticle, a small "net" made of human hair Lacaille used to put on the ocular of his telescope. Pictor, Dorado, Reticulum & Horologium make together a foursome of small constellations between Canopus and Achernar.[[/note]] and '''[[http://en.wikipedia.org/wiki/Telescopium Telescopium]] the Telescope''', [[note]]Below Sagittarius and the Southern Crown and above the Peacock, it's a humble but right homage to the most important astronomical tool. Significantly, the Telescope was put by Lacaille near the Microscope. Telescopium is the biggest Lacaille's constellation after Sculptor, Fornax and Octans.[[/note]]. The Sculptor and the Furnace are placed near each other below the Whale; the Sculptor is near the bright star Fomalhaut, the Furnace is ringed by a bend of the Eridan River. They are medium-sized constellations, about as large as Canis Major or Carina, whose area is visible from the USA. Though very difficult to spot because of their faintness, both are interesting because contain several galaxies. Some are small members of our Local Group, ex. the "Fornax Dwarf" and the "Sculptor Dwarf", both only a bit more distant from the Milky Way Galaxy than the Magellanic Clouds; others pertain to distant clusters. One galaxy of the latter (in Fornax) is named the Giant Barred Spiral Galaxy: this is indeed an often-cited example of a [[ExactlyWhatItSaysOnTheTin barred spiral galaxy]], because it has only two spiral arms protruding from a central "bar". [[note]]Interestingly, it was recently hypothesized that even our Galaxy and the LMC are barred spiral galaxies, but the central bar of the Milky Way is not visible from Earth, and that of the LMC is very incospicuous. It was also very recently found (thanks to radiotelescopes) that a "phantom" dwarf galaxy, the [[http://en.wikipedia.org/wiki/Sagittarius_dwarf_elliptical_galaxy Sagittarius Dwarf]], lies at the opposite end of our Milky Way in respect to where we are, and could even be "sucked" by our own Galaxy in the future![[/note]]. The Sculptor contains the South Pole of our own Galaxy; this explain why so many distant galaxies are visible in these two constellations (like in "Coma Berenices", that contains the galactic North Pole). Let's end our trip among constellations with '''[[http://en.wikipedia.org/wiki/Octans Octans]] the Octant'''. [[note]]This was an ancient astronomical instrument very similar to the Sextant portrayed in the equatorial sky[[/note]]. This is a medium-sized but faint triangle-shaped constellation, but has a very special privilege: is ''this'' the constellation whose area contains the celestial South Pole. The Octant is slightly wider in area than Ursa Minor at the North Pole, but unlike the latter, its visible star closest to the south Pole (the Sigma) is barely visible to a naked eye.

* '''[[http://en.wikipedia.org/wiki/Hydra_(constellation) Hydra]]: the Sea Snake.''' Some vast constellations appear like a very long line of faint stars meandering among other more solid figures, often with a group of stars which mark one end of the line. Draco is a good example near the North Pole; others are Pisces and Serpens. However, the two UpToEleven examples are better-visible from the Southern Hemisphere: Eridanus the River (see further) and Hydra the Sea-Snake. [[note]]Also called with the weird name "the Female Sea-Snake" to distinguish it from the [[TheUnfairSex much humbler]] Hydrus, the "male" sea-snake near the South Pole.[[/note]] Theoretically, Hydra should be the mythical seven-headed monster defeated by Hercules during one of his 12 fatigues, but is always portrayed as an one-headed snake. Although less-known than other celestial figures because of its indistinct appearance, the Sea-Snake detains the special record of the largest by area among all 88 constellations in the Sky. Its head is marked by a small bunch of stars near the Crab just above the celestial Equator; the remaining body is below the equator, traveling between Leo/Virgo and the Centaur and ending near the Scales. Though mainly visible in the northern Spring, the Sea-Snake's head is already visible in Winter and its tail still in Summer, giving an idea about its extreme length.