A very large constellation
The constellation Lion
In the introduction I was talking about the spring constellation, precisely because it is best seen in this season, despite the unscientific tradition erroneously associating it with the months of July-August and in particular with the period that is not by chance called the sunrise. In this diagram, realized as usual through Stellarium, we see the constellation in which the main star, Regulus, is surmounted by an asterism (grouping of near stars) called "the scythe", because it reminds the well-known agricultural tool.
The Sun in the Lion
In this other diagram, realized reworking two images (similar to the previous one) of Stellarium, we see that the Sun enters in the constellation of the Lion on August 10th (St. Lawrence's day) to go through it in more than a month, so much so that it comes out only on September 16th: along its path it crosses the famous star Regulus, a star of first magnitude among the closest to us, with a distance of "just" 77 light years.
The name, the story, the myth
It is a constellation known since ancient times, being a constellation of the zodiac. Precisely it was the constellation that, in Babylonian times, hosted the summer solstice and that's why in August we still talk about Solleone. It was therefore identified with the Sun also in the remaining Mesopotamian civilizations. While in Egypt it was connected to the heliacal rising with Sirius and the flooding of the river Nile in summer. The link of the constellation with the river Nile perhaps explains why Greek and Roman architects often placed a lion's head at the fountains and fountains; the reason may have been taken up by the Egyptians, who decorated the doors of their canals with lion-like protomes.
The constellation Lion owes its name to one of the labors of Hercules, and precisely to the killing of the terrible Lion of Nemea which represents the first of the twelve labors.
The lion lived in Argolida, in a cave with two openings, and went out only to kill the local population. Its skin was resistant to any weapon, which made the lion invulnerable.
Hercules, during a duel with the beast daughter of Typhon, whose tracks he had followed in the woods, saw three arrows and a sword break against the lion's skin, in fact his mantle, as said, was invulnerable to stones and metal. Hercules fought with his bare hands, lost a finger and his armor, but still managed to grab the lion by the mane, forcing him to crouch down and declare himself defeated. Hercules carried the lion on his shoulders to Mycenae, but Eurystheus ordered him to bring it back. In another version, he choked the beast and used his own claws to remove its skin and, clothed in the bare, became invulnerable in turn. Often in the depiction in star maps, Hercules is depicted with the skin of the Nemean lion, his head as a headgear and the rest of the skin along his back, or holding the trophy in his hand. When he died, the lion was put into the sky by Zeus.
Although Hercules managed to beat the lion, in the sky the constellation dedicated to the feline is much brighter than the one dedicated to Hercules, and in fact the Lion is among the brightest constellations of the whole sky.
The constellation is also said to represent the lion in the tragic story of Pyramus and Thisbe.
In Ovid's Metamorphoses (43 B.C.- 17 A.D.) it is told of how the parents opposed their union. The two lovers converse secretly through a crack in the wall that separated their houses. One day they devised a plan to meet outside the city, at a mulberry tree with white blackberries. Thisbe was the first to arrive at the meeting, but while waiting for Pyramus she was threatened by a lion dripping with the blood of a recent victim. As she escaped, her veil slipped and the lion gnawed and tore it before leaving.
When Piramo arrived in the place of the appointment, breathless, he saw the veil of Thisbe on the ground, torn and bloodied, and believed it had been devoured by the beast that he knew had been sighted in the surroundings. Unable to warn his beloved, desperate for what had happened, for not having protected her, he drew his sword and stabbed himself to death. Running in his footsteps, Thisbe saw Pyramus lying on the ground dying, immediately threw himself on her body in tears and when he died, desperate, drew his sword and stabbed himself with it. The blood of the two lovers coloured the blackberries from white to red, the colour they still have today.
The unfortunate lion, captured, was sacrificed to the father of the gods and placed by him in heaven to remind all parents not to hinder the love of young people.
Representation over time
Speaking of the Lion, one cannot help but see immediately how it was represented in antiquity and in more modern times.
In the Uranometria, the lion all things considered cannot be said to have a beautiful mane, and so also according to Hevelius
representing him with a very long tail and ready to jump on the prey.
Finally Stellarium represents it in a much more stylized and modern way, but this time with a beautiful mane and in the act of emitting a sound roar.
Since the constellation of Leo is one of the twelve of the Zodiac (the zone of sky crossed by the Sun in a year) I continue in the tradition of showing one of the twelve stamps issued by the Republic of San Marino in the 70s, the one that had a face value of 5 lire!
Many stars nearby
In this constellation there are many stars close to our Sun: among the nine below 60 light years, we find four below about 20 al. Let's go to analyze them.
The closest one is called Wolf 359, placed at a distance of 7.78 light-years and therefore it occupies the third position in the ranking of the nearest stars, just behind the famous Centaur stars: its name, which in English means wolf, is not a wrong translation of lion, but it is more simply the name of the German astronomer who had discovered this red dwarf of thirteenth magnitude and therefore visible only with appropriate instruments.
The proximity of this star (with a vaguely disturbing name) has caused the inevitable involvement in science fiction events related to Earth and its invasion by fearsome aliens: I'm referring to the events of Star Trek NG, where the very bad Borg fight and win against the Federation of United Planets the Battle of Wolf 359, a kind of Galactic Caporetto.
But let's abandon these fighting stories, to return to something more scientific (with some dutiful flight to fantasy, as always!): the star Wolf 359, a variable also known as CN Leo, is very close to us and therefore we expect our Sun (observed from the vicinity of the star) to be quite bright. The confirmation comes from my friends Cnleonini, with an unpronounceable name, but they call themselves Borghiani, you look at the case sometimes...
We see in fact (always thanks to Celestia) that the Sun shines of magnitude 1.7 in an area of sky not very rich in bright stars: however, our star has always been known to my friends, who always go around in plain clothes and all live in villages. They have always captured our television with big antennas and follow our tennis in particular: they have always been great fans of the famous Swedish ice tennis player, who is called Borg.
We now move on to the second nearest star: Gliese 388 (a variable also known as AD Leo) is 16 al from us and from this star the Sun shines of third magnitude in an area of sky full of stars in our southern sky. Having said that my friends Addioleoni work in strange societies in which they are all AD, while their leaders are the ushers, let's go to the third star for proximity.
the Sun seen from the star 2MASS J0937-2391
It is a star known with its initials of belonging to a star catalog, 2MASS J0937-2391, placed 20 light years from our Sun, which from that distance and position shines in the sky of the same brightness of the previous case with practically the same star $campo$: my friends Duemassoni do not enjoy a good reputation in the neighborhood, so I leave them alone and continue beyond.
The fourth star closest to us, at 21.8 to the Sun, is the one called Gliese 408 and also in this case the Sun is seen as a star of fourth magnitude, but still visible to the naked eye.
Moving further and further away from the Sun in the direction of Leo, we find another star in the Gliese catalogue (Gliese 436, at 33 al: from this link we see what the Sun looks like). Then we have Denebola (β Leo, at 36 al, with the link to the photo of the Sun), followed again by a small group of three stars placed between 58 and 59 light years, formed by Zosma (δ Leo) and the double star 83A and 83B Leo.
Deep sky objects
Inside the constellation of Leo we meet several Deep Sky objects: the first five are galaxies already known and catalogued by Messier and here taken from the HST (clicking on each photo you can see the version with more details): let's start from the galaxy M65
the galaxy M65
followed by the galaxy M66, which is much more striking
the galaxy M66
and then again from the beautiful M95
the galaxy M95
accompanied then by M96, also rich in coloured shades
the galaxy M96
and finally another galaxy, M105, absolutely spectacular, with shades of color clearly different from the galaxies seen before.
the galaxy M105
After all these galaxies that appear majestic thanks to their angle of view, we now move on to another galaxy, this time visible by cut, NGC 3628 : also from this point of view, the celestial object is really beautiful!
the galaxy NGC 3628, visible by cut
And finally, always thanks to the Hubble Space Telescope, here is a protoplanetary nebula, the IRAS 09371+121212, nicknamed The Frosty Leo Nebula: wonderful!
Some big stars, but not only
The constellation of Leo presents several giant stars: of these, three stars have a diameter greater than 100 times that of our Sun while another half dozen have a ray above about 60 solar rays: in the diagram we see that they are all red giant stars (spectral class M), except the last two of spectral class K: this time in the diagram I managed to make them all enter, to form a sort of cosmic patch-work, where the predominant color is red.
The biggest star of the group (72 Leo) has a diameter of 177 times that of the Sun and in this photo realized with Celestia we see it shining threateningly, from a distance of 10UA, from which it subtends a diameter of almost 9°. As said before, usually the biggest stars in a constellation are almost always red supergiants: seen one, in the background all the others are similar, apart the diameter.
For this reason, since the last two biggest stars of the constellation Leo are class K (and therefore more yellow-orange, like Aldebaran), I thought to photograph 18 Leos from a distance of 10 UA: although smaller, but still 62 times as beautiful as our little Sun, this star shines with a much less annoying light, much closer to that of our Sun.
In the title of the paragraph I wrote that I was going to talk about big stars, but not only: this time I thought I would show you a very small star, but...
the star 2MASS J0937-2931 from the same distance of the Moon
Here we see the already mentioned 2MASS J0937-2391, the little star 20 meters away from us, a brown dwarf of class T6 with the characteristic dark red color: its diameter is an eighth of the diameter of the Sun and in the photo of Celestia, I have immortalized it from a distance roughly equal to that of the Moon here! At this distance it covers a good 20° of the sky against just half a degree of our natural satellite, which I inserted in a box on the left to compare its dimensions.
You know that I don't lack imagination: think about how big and bright the Moon appears in our sky, for example in a night photo when it appears from above the Colosseum (published by MNews.it on the occasion of a "super moon")... Add now for a strange spell a brown dwarf star at his side, forgetting for a moment small details such as the different brightness and coloring of the sky in the presence of this reddish object, the effects on the earth's surface and on our mood: well, I would say first of all that the dwarf everything would seem less than a dwarf and would be definitely disturbing and oppressive with its more than 80 thousand km in diameter.
In conclusion, after having known in the other constellations many stellar monsters (whose size at this point becomes absolutely unimaginable) it seemed to me necessary to show also a representative of this kind of stars, surely very numerous in the universe, but very difficult to observe because of their very poor brightness: this brown dwarf was discovered in fact only thanks to its discreet closeness. Obviously that of Celestia is an imaginary representation of this star, created by programmers.
The names of the stars
In the constellation of Leo there are many stars that in the course of the centuries have received a name, most of the times from the Arabs: let's see them together, to realize that of Leo they have given a very detailed "anatomical" representation.
- Rule (α Leo): Latin name, the little king
- Denebola (β Leo): the tail
- Algieba (γ1 Leo): the mane
- Zosma (δ Leo): the belt
- Algenubi (ε Leo): the southern part
- Adhafera (ζ Leo): the eyebrows
- Al Jabhah (η Leo): the forehead
- Chertan (θ Leo): the ribs
- Minkarasad (κ Leo): the nose
- Alterf (λ Leo): the end (of what? mystery!)
- Rasalas (μ Leo): the lion's head to the south
- Subra (ο Leo): found on the internet
- Shir (ρ Leo): found on the internet
- Zubrah (72 Leo): the mane
This constellation is clearly visible in spring and is recognizable thanks to that configuration of stars known as "the sickle", located just north of Regulus.
The Lion is seen low on the northeastern horizon, at 9 p.m., at the end of the year, while then it dominates in the south, high in the sky, from mid-April to mid-May (the constellation is in fact very large, as we have seen).
We finally find it low on the north-western horizon, at the beginning of August.