Winged horse without wings
The constellation of Pegasus is one of the most recognizable in the sky, since it is located in an area not very rich in stars and for the shape that distinguishes it, the so-called Square of Pegasus. If we look at the photo taken from the Stellarium program we see its appearance as if it were upside down, beyond the square that, depending on how you look at it, sometimes becomes a huge rhombus with the tip at the bottom.
I said upside down precisely because observing the constellation in the sky and above all showing it to friends and interested people, it will never be possible to "see" the horse, which in this case doesn't even have wings... As we will see later, the representation of the animal in antiquity and modernly is always upside down, but for those used to PCs and graphics programs, it takes a moment to fix things. As another option, we can travel around the world or even take advantage of the Stellarium program: for example from Cape Town, but already from Central Africa, Pegasus can finally be seen "straight ahead" !
The name, the history, the myth
Mythologically, Pegasus is notoriously a winged horse, according to a tradition that probably originated in both Mesopotamian and Etruscan myths. It is said that the sea god Poseidon (Neptune), god of seas and horses, turned into a horse to seduce Medusa.
When Perseus cut off the head of the Gorgon, from the blood gushed after the cut, Chrysior was born - a warrior armed with sword - and the mythical horse, who immediately ascended to Olympus and placed himself at the service of Zeus. Pegasus is associated with poetic inspiration: a source consecrated to the nine Muses, would be generated from the ground when his hooves beat on Mount Helicona, Hippocrene or "source of the horse". He is then found as the steed of the hero Bellerophon, horse tamer and slayer of the Chimera, the fire-breathing monster born of Typhon and Echidna who was devastating Lycia, to whom Athena would appear in a dream holding a golden bridle.
The two became inseparable, and lived many adventures together, which brought such fame and wealth to Bellerophon that he mounted his head, even going so far as to aspire to a place in Olympus with the gods and achieve immortality. For this arrogance Zeus wanted to punish him: he sent a horsefly that stung Pegasus who broke away and brought down Bellerophon.
After the death of Bellerophon, Pegasus returned to Olympus, stayed with Zeus, who used it to pull his chariot and his lightning bolts into the sky. Subsequently, on his own initiative, he flew towards the highest part of the sky, and when he arrived he turned into a sparkling cloud that generated stars that formed the constellation.
In some versions of the myth, he accompanied the exploits of Perseus, who would ride him during the return journey and the rescue of Andromeda.
But for the authors of the past, this group of stars were simply the "Horse". Even Eratosthenes doubts it was Pegasus, since the wings of the asterism are missing.
It is not by chance that Pegasus was born from the Gorgon Medusa, who is none other than the image given by the Greeks to the Libyan goddess Neith, the Great Mother. As for the horse, it was originally a chthonian animal associated with the Great Mother, which rose from the bowels of the earth or from the depths of the sea. Son of the night, he was like the Great Goddess, bearer of life and death, bound to the water of which he knew the underground paths, and for this reason he traditionally had the gift of making springs spring with a blow of his hoof.
Later, with the advent of the Indo-European patriarchal religion, he was associated with Poseidon. It is noted how the legend of the birth of Pegasus of Medusa, fertilized by Poseidon, reminds, although with many differences, that of the same god who generates Arion in Demeter, not accidentally transformed into a mare. Both myths describe how the Hellenes devoted to Poseidon forcibly married the priestesses of the Moon, without letting themselves be frightened by their masks of Medusa, and took control of rain rites and the cult of the sacred horse.
For this reason it was said that the first horse had been created by Poseidon when, in competition with Athena for the possession of Attica, he had made it spring from the earth. And it was no coincidence that Pegasus jumped from Medusa's neck and drank at the source Pirene, on the road leading to the sanctuary of Poseidon.
The representations of Pegasus over time
Let's see how the constellation was represented in the Uranometry
by the astronomer Hevelius (already overturned and mirrored, therefore with illegible writing!).
and according to Stellarium
In all three cases you always see a winged horse, but you can't tell where the wings are. With the powerful means at our disposal... now we will see them appear as if by magic!
Let's take advantage of Pegasus...
Speaking now of distances, we have four stars below 60 light years from us: ι Peg at 38 al, 85 Peg at 40 al (so very close, but only on a cosmic scale), 51 Peg at 51 al and ξ Peg at 53 al. My friends iotapegini and the trusty program Celestia, tell me that from their star the Sun can be seen as a star of fifth magnitude, in a zone of sky where Altair and Sirius coexist, together with Alphard. Jumping at even feet the second star in order of distance (hoping that my friends eighty-five will not be offended), we now move on to the third star.
The fifty-one Pegs (I recommend the accent!) are very proud because the star 51 peg from our parts holds the record of being the first star (which has exactly the same spectral class as the Sun) of which the presence of a planet (called therefore extrasolar) has been ascertained: as usual it has been called 51 Peg b or by some Bellerophon.
Thanks to Celestia, but I could also say thanks to my friends who sent me a postcard, arrived a few years late because of a postal disservice (the whole world is a country...), we can see a free interpretation of the gaseous planet in orbit of the Sun's twin star. Always my friends told me that the star 24 Cuc is famous in their area because it was the first to present a gaseous planet extracinquantunpegano, but given the difficulty of naming this class of planets, they abandoned the enterprise ... Too bad! With the progress of their technology, sooner or later they would have found our Earth!!!
Many big stars
From the first glance, looking at the little picture next door and then clicking it to see the image in real size, the constellation of Pegasus has several stars inside it that are much larger than our dear Sun. Limiting ourselves to stars of physical size greater than 50 times our yellow dwarf, we see really many of them, in some cases grouped in order not to overwhelm an already rich image: in fact we see three stars at 60x (2 Peg, 55 Peg and χ Peg) and other three at 100x (β Peg, ψ Peg and 80 Peg). The biggest ones of the constellation are 57 Peg (180 times the Sun) and Enif (ε Peg, 172 times). Those indicated in the diagram are almost all of spectral class M (represented as always with red disks), while Enif and 12 Peg are class K and finally 9 Peg is class G5, very similar to the Sun (G2).
Taking a closer look at the diagram we can see in the background the monsters we met in our previous trips (the various P Cyg, ρ Cas, Antares and Betelgeuse) while later on we can hardly see Rigel, Aldebaran and our little Sun...
Several stars baptized
- Markab (α Peg): derives from the Arabic the shoulder, of the horse
- Scheat (β Peg): from Arabic the tibia
- Algenib (γ Peg): from Arabic the side (always the horse's side...)
- Enif (ε Peg): name that could derive from the Arabic nose
- Homam (ζ Peg): with dark meaning
- Matar (η Peg): from Arabic the rain, that with a horse obviously has little to do with it
- Biham (ζ Peg): another name with an obscure meaning
- Sadalbari (μ Peg): also this name has a meaning not directly related to the equine world.
When is Pegasus visible?
It is a very visible constellation from our latitudes, although upside down as we said at the beginning. At the time chosen to show it to our friends, 9 p.m. Pegasus appears on the eastern horizon towards the end of July and can be seen until mid-February of the following year when it will be low on the western horizon. Its peak is towards the end of October, when it will be very high in the sky, in a southerly direction, between 50° and 80° on the horizon.