(translation from Italian by Giuliana Giobbi)

Here is a short and simple description of the pictures you will find in the Nasa Selfies app, which you can read and record for your own astro-documentary. Besides, clicking on the name of the object, a link will be opened with the picture of the catalogue and your descriptions. If you want to send your own description and find them here in these pages (with your name, as author), you should fill the form you will find in this page.

  • A Milky Way Project Nebula
    In the yellow bubbles of this Milky Way nebula new stars are forming. In the green parts,  molecules are being issued, whereas dust comes from the red ones.  The yellow colour means that there is an overlapping of dust and molecules.
  • Andromeda Galaxy
    The Andromeda Galaxy is a giant spiral galaxy, 2 millions and a half light year away, in the direction of the Andromeda constellation. It is the largest galaxy near our own galaxy, the Milky  Way. It is so big, that you can even see it with the naked eye! My expression is worried, because this galaxy is  moving very fast towards us and perhaps, in a few billions years, we shall collide.
  • Antenna Galaxies
    These two spiral galaxies are colliding, about 70 millions light-year away from us, in the direction of the Raven constellation. They are called  Antennae because of their long whiskers going outwards, formed by gas, dust and stars. The two galaxies have been embracing each other for a few hundreds millions years, and many stars are being formed along their arms.
  • Aquila Bubbles
    This cloud of gas and dust is full of bubbles, which are blown up by the wind and the radiations of huge young stars. Each bubble is about 10-30 light-years, and is full of hundreds, or thousands of stars. The region is placed within our  Galaxy, the Milky Way, in the Eagle constellation.
  • Arp 142 Galaxies
    These two galaxies have met… and for them, it did not end very well. They are called respectively NGC 2936, which was once a spiral galaxy, and NGC 2937, a smaller elliptical galaxy. Don’t you think they look like a penguin  protecting its egg?
  • Bubbles within bubbles
    This is a giant bubble, sculpted in space dust by the stellar wind, with smaller bubbles inside. The big bubble is in the centre of the picture, whereas the two smaller – yellow – bubbles lie inside its edge.
  • Cartwheel Galaxy
    This galaxy is known as Cartwheel. Undoubtedly, it is a very peculiar galaxy. It is about 500 millions light-year away, in the direction of the Sculptor constellation. It is not so large: more or less 150 millions light-years, therefore slightly bigger than the Milky Way.
  • Cassiopeia A
    Cassiopeia A is a reminder of a Supernova, in the constellation of Cassiopeia,  and is quite easy to be found, because it looks like a W. It is very bright in the radio waves, but hardly visible… therefore it cannot be seen with the naked eye. The Supernova which gave origin to Cassiopeia A blew up about 11 thousand years ago. The light of this explosion should have reached the Earth about 300 years ago.
  • Cat’s Paw Nebula
    Here is the Cat’s Paw Nebula o, one of the nearest star-forming regions inside the Sagittarius arm of the Milky Way, which is visible in the constellation Scorpius.
  • Cepheus C and Cepheus B Star Cluster
    This picture represents a real family portrait, with newborn stars, parent stars and grandparent stars. Newborn stars are formed in dense clouds of matter, such as the dark streak forming Cepheus C, on the left. While stars are growing, they produce winds which blow away gas and dust outwards, so as to form beautiful bright nebulae, like the white shiny point, which apparently reddens the upper part of the larger nebula, up on the right. Finally, dust and gas scatter away, and star clusters remain alone in the space, as in Cepheus B.
  • Christmas Tree Cluster
    In the constellation of the Unicorn, it’s Christmas all the year round! When looking in the direction of this constellation, indeed, we can find a cluster of about twenty blue – therefore young – stars, arranged in a triangle, pointing south: a peculiar shape, which actually reminds us of a Christmas tree, but only if we look at it in the Southern Hemisphere! All around, various protostars are being formed in the surrounding nebulae, and complete the whole, just like colourful Christmas decorations.
  • Cigar Galaxy
    The Cigar Galaxy (also known as M82) is a galaxy active in the constellation of Ursa Major. It is about 12 millions light-years away from the Earth, very near to the larger, well-known M81. It is a galaxy in which star-forming is much more intense than usual, in comparison with other galaxies, such as our own. Its name comes from its elongated shape, similar to a cigar.
  • Coyote Head Nebula
    The picture of this beautiful nebula is part of one of the largest panoramic photos of our galaxy, a combination of over 2 millions infrared pictures taken by the Spitzer Space Telescope. This nebula is called Coyote Head because of its peculiar shape. However, since phantasy knows no bounds, someone says it looks like a fish, or a raccoon. The picture is made up of various filters, which show its composition: red is for dust, green is for hot gas, white is where gas and dust are mixed.
  • Crab Nebula
    The Crab Nebula is a reminder of a Supernova, which can be seen in the constellation of Taurus. It is more than six light-years large, and its gases are expanding at a speed of 1500 kilometers per second. The Supernova which  produced it was observed for the first time on July 4, 1054, and was recorded by Chinese and Arab astronomers at the time. It is placed 6500 light-years away from the Solar System, therefore the event which produced it, in fact, had taken place 6500 years before its discovery, in 1054, namely about 5400 b.C. The centre of the nebula hosts the Crab pulsar, a Neutron star with a diameter of about 30 kilometres.
  • Cygnus X Star-Forming Region
    Precisely in the heart of the constellation Cygnus, about 5000 light-years far from us, there is one of the most troubled star-forming regions in the whole galaxy, the Cygnus-X region! A beautiful but violent site of continuous star birth, this region – here photographed by the Spitzer Space Telescope  – contains very young bright stars, expanding gas bubbles, blown up by the stellar wind produced by massive stars and dense gas filaments. It stretches over about 600 light-years, and is the largest nebula cluster known in the whole of the Milky Way. It is obviously one of the best regions for the study of the mechanisms leading to star-forming. 
  • Dragonfish Nebula
    The Dragonfish Nebula is 30 thousand light-years away from us, in the direction of the constellation of the Southern Cross, and is about 450 light-years large. From the giant stars inside this nebula,  strong winds blow, which have been capable of creating a gas bubble, which is over 100 light-years large, shaped like the mouth of a dragon fish, a giant fish with thirty-two teeth. They say that its largest and brightest stars – namely, its “eyes” –  are newborn stars. This nebula contains some of the most impressive stars of the Milky Way galaxy. Because of both its distance and position, it is totally invisible to visible light, because the interstellar dust absorbs and reddens its light, thus hiding it. However, the Spitzer telescope saw it well, in the infrared.
  • Enterprise Nebula
    This object, which reminds us the famous Star Trek spaceship, represents a region belonging to the disc of our galaxy, the Milky Way, and shows two star-forming regions which, when observed in the visible light, are hidden behind a dust haze. Spitzer’s ability to peer beyond the dust clouds revealed many star-forming places.
  • Eta Carinae Star-Forming Region
    The Eta Carinae Nebula is placed in the heart of the Milky Way, but unfortunately we cannot observe it… it can only be seen (very well, even with the naked eye) from the Southern Hemisphere, in the Carinae constellation. It is one of the largest regions containing ionized hydrogen, discovered inside our Galaxy. Lots of star have been forming inside the nebula. It stretches over 260 light-years, and is about 7500 light-years away from the Earth. The nebula surrounds various open clusters, as well as one of the most massive stars we know, namely Eta Carinae.
  • Flame nebula
    The Flame Nebula is a diffused nebula, which reminds us of a flame, visible in the constellation of Orion. It lies very near the very bright star Alnitak, to the extreme left of the Orion’s belt, so much so that its is almost overshadowed by its luminosity. It is a part of Orion’s molecular cloud, and can be observed with a powerful telescope.
  • Galactic Snake
    NASA’s Spitzer Space Telescope caught something “creeping” in the plane of our galaxy. The object, which looks like a snake, is actually the nucleus of a thick, dusty cloud, site of an intense forming of massive stars (yellow and  orange dots). Because of its peculiar shape, this filamentous region, placed about 11thousand light-years away from us in the constellation of Sagittarius, is called Galactic Snake(o). 
  • Galactic Center
    All the stars of the Milky Way rotate around the Galactic Center. It lies about 8000- 26000 light-years away from the Earth, in the direction of the constellation of Sagittarius, where the Milky Way is at its brightest stage. Just there, in the centre of the Milky Way, there is a huge black hole… a supermassive black hole.
  • Ghost of Jupiter
    The NGC 3242 nebula, also known as ‘Ghost of Jupiter’ is a Planetary Nebula inside the Hydra constellation, about 1400 light-years far, and even visible with an amateur telescope. It was discovered by William Herschel on February 7, 1785 in South Africa. Its name comes from its similarity to Jupiter, even though it is not a planet, but rather a remnant of a star, once the nuclear fuel is spent. The outermost layers expand, thus forming the nebula, with a neutron star in the middle.
  • Green City
    Here we can see two very bright stars, which light up a greenish mist, composed of hydrogen and carbon compounds, which here on the Earth can be found in the exhaust gases of vehicles. On the other hand, in the Space, these compounds form inside dark clouds, which give origin to the stars. The yellow streaks you can see near the star, in the top left, are probably due to specks of dust, aligned to magnetic fields.
  • Helix Nebula
    The Helix Nebula is one of the planetary nebulae nearest to us. It  lies 650 light-years away from the Earth, in the constellation of the Aquarius. Of course… it is not so near! It is about 2 and a half light-years large, and formed at the end of the life of a star similar to the Sun.
  • IDCS J1426.5+3508
    This is a galaxy cluster in the Bootes constellation, which is very easy to find, because it contains the very bright star Arcturus. It is 10 billions light-years away… that’s a lot! Therefore this picture dates back to the time in which the cluster was just over 3 billions and a half years old.
  • IRAS 13481-6124
    This is a star-forming region, where you can clearly see a very bright young star, in the top left, which is about twenty times more massive than our  Sun, and five times as large. It is the first rather large baby star which astronomers could study well, together with its dust disc, which still surrounds it.
  • IRAS 19312+1950
    The bright red star at the centre of the beautiful nebula of this picture, taken by the Spitzer Space Telescope, is called IRAS 19312 + 1950, an acronym coming from its sky coordinates. It is a very peculiar star: it is about 10 times more massive than our own Sun, and delivers 20000 times more energy. According to astronomers, it is a newly-born protostar. However, the strange thing is that it also has those features which are usually connected with very old stars. It is indeed a mysterious object!
  • Iris Nebula
    Iris Nebula is a reflection nebula, i.e. a cloud which reflects the light of a few nearby stars, wrapped. It is about 1400 light-years away, and is about 6 light-years old. Probably, it is a part of the large Cepheus molecular cloud. With ideal sky conditions, it can be viewed with powerful binoculars. Its name reminds us of the blue Iris flower… the main colour of the nebula, hallmark of the  grains of sand reflecting starlight.
  • Jack-o-Lantern Nebula
    This cloud of gas and dust has been nicknamed “Jack-o’-Lantern Nebula”. The stellar winds originated by a star – which is 15 to 20 times heavier than the Sun – inside the cloud, swept away the surrounding dust and gas, and pushed them outwards, thus hollowing out eyes and mouth of a scary cosmic Halloween pumpkin.
  • Large Magellanic Cloud
    The Large Magellanic Cloud is a dwarf galaxy, probably a satellite of the Milky Way (in that it is attached to our galaxy by gravity, just like the Moon is attached to the Earth).  It is placed about 160thousand light-years away, and is the galaxy nearest to the Milky Way, after the Canis Major dwarf galaxy (42thousand light-years) and the Sagittarius one (52thousand light-years). Its mass is ten times smaller than the one of the Milky Way, and contains about 20 billions stars. Obviously, it is much smaller than the Milky Way, around 14thousand light-years. It is often considered an irregular galaxy: in fact,  it holds a thick “bar” of stars crossing its centre, and this could mean that, originally, it was a barred spiral galaxy, just like our own, which, because of huge tidal forces – due to the interaction with our galaxy, and with the Small Magellanic Cloud, has suffered deformations. It can be seen with the naked eye from the Southern Hemisphere!
  • Messier 17
    This nebula has several names: indeed, it is called Omega Nebula, Swan Nebula, Horse-Shoe Nebula, Lobster Nebula… over and above M17, from the index of the well-known Messier catalogue, which indicates some of the most beautiful diffused objects, visible in the sky. It is an emission nebula, placed  in the constellation of Sagittarius, about 6thousand light-years away from us, and it so bright that it can even be see with the naked eye. In this nebula, many stars are forming, some of which have gathered to form an open cluster of 35 stars, which is rather overshadowed by dust. The bright red colour of the nebula is due to the excitation of hydrogen atoms. The mass of the brightest zone is about 800 times the mass of the Sun.
  • Messier 78
    M78 is the brightest reflection nebula in the sky, and is visible in the Orion constellation (just above the belt). It is about 1600 light-years away from the Earth, and stretches across 4 light-years. It is lit up in particular by two stars, even though we know more than 45 stars forming inside it.
  • Messier 81
    Also known as Bode Galaxy, it is a spiral galaxy about 12 millions light-years from the Earth, in the Ursa Major constellation. It contains about 250 billions stars, and is therefore slightly smaller than the Milky Way. Most infrared emission of this galaxy, which can be seen in this picture, is due to the  interstellar cloud, which can be found mainly in its spiral arms, where new stars are forming. The young, bright newly-born blue stars blu heat up the dust, which issues infrared radiation.
  • Messier 87
    When in 1781 the French astronomer Charles Messier observed, in the Virgo constellation, the object to which he gave number 87 in his catalogue, he was  convince it was a nebula. However, M87 is a supergiant elliptical galaxy, indeed one of the largest galaxies of the local Universe. It is placed at a distance of about 53 millions light-years away from us, and has become famous because, in 2019, thanks to the International project Event Horizon Telescope,  a team of over 300 astronomers succeeded in realizing the first image ever made of the supermassive black hole at its heart. 
  • Messier 94
    M 94 is a spiral galaxy, visible in the constellation of Canes Venatici. Here it is seen almost perfectly from the front. It should be about 16 millions light-years far away… however, we are still not sure of this distance. It is moving away from us at a speed of 370 km/s. It seems that in this galaxy there is no dark matter … and this is quite strange!
  • Messier 100
    M100 is a spiral galaxy placed in the direction of the constellation of  Coma  Berenices, 55 millions light-years away from us. From the Earth it is seen from the front, therefore we can easily observe its spiral arms. It has a mass of about 160 billions times the Sun’s mass, and its diametre is slightly higher than the one of the Milky Way, i.e. 107thousand light-years. It is moving away from us at a speed of 720 km/s.
  • Milky Way
    The Milky Way is the galaxy in which we are living; it houses the Solar  System. This name comes from the fact that, if the night sky is clear enough, we can observe a brighter strip which looks like milk. This glow, in fact, is due to a few hundreds billions stars, which, together with the Sun, shine in our galaxy. It is a spiral galaxy, about 100thousand light-years wide, and we are actually in the suburbs, about 26thousand light-years far from its centre. Fortunately … since there is a huge black hole in the centre!
  • Monkey Head Nebula
    On the northern border of the Orion constellation, about 6400 light-years far from us, there is a nebula, made of gas and dust, called Monkey Head. This peculiar name derives from its unusual shape, which reminds us of a monkey head, seen from the front. It is a region characterized by the presence of several young stars, and stars being formed. Its reddish colour depends from its composition: indeed, it is the result of an interaction between the ultraviolet emession from the stars, and the hydrogen of which it is mainly composed.
  • Mountains of Creation
    This picture shows the eastern border of a region known as W5, in the constellation of Cassiopeia, 7000 light-years away from the Earth. This region is dominated by one massive star, whose position outside the area of this picture seems to be marked by finger-like pillars. These pillars are huge, and look like a mountain chain. They are actually over 10 times larger than the ones of the Eagle Nebula. The largest pillar observed by Spitzer encloses hundreds of stars, which are still in the embryonic stage, whereas the second largest contains dozens of stars.
  • Ngc 1333
    Ngc 1333 is a small diffused nebula, 1000 light-years away from the Earth, in the Perseus constellation. It is part of the Perseus Cloud, one of the low-mass star-forming regions nearest to the Solar System. Most of the visible light of the young stars in this region is shadowed by the thick dust cloud where they formed. With Nasa’s Spitzer Space Telescope, scientists could detect the infrared light of these objects, namely, they could look through the dust, in order to understand how stars similar to our Sun are born. Young stars in Ngc 1333 do not form a single cluster; rather, they are divided into two subgroups. One group lies north, near the red nebula of this picture. The other group lies south, where we can see yellow and green zones, in the thicker part of the gas cloud. With the Spitzer telescope, scientists manage to observe hot discs of dust surrounding the stars being formed. In particular, scientists are looking for differences in the properties of the dust discs of the two groups, in the hope of finding some suggestion, so as to understand how stars and planets in this beautiful region are formed.
  • North America Nebula
    This is an emission nebula in the Swan constellation, near the bright star Deneb. It is a site of important star-forming, and constitutes the lit-up side of the large system of gas and dust, known as Fissure of Cygnus. Thanks to its luminosity, width and shape, which looks like the North-American continent, it is one of the most photographed objects of the Northern hemisphere.
  • Orion Nebula
    The winter sky shows us one of the most beautiful and luminous constellations, namely, Orion the hunter. If we look south of the three stars which compose the Belt, along the Sword, we find a remarkable nebula, which can often be seen with a naked eye: i.e. the Orion Nebula. It is placed about 1270 light-years away from us, and is the star-forming region nearest to our Solar System. Probably, it is by far the most photographed cosmic object because of its beauty, and is also the most studied one: its proximity, indeed, is an ideal place where we can study the processes leading to star-forming and kindling.
  • Perseus Nebula
    This is a picture of the Perseus molecular Nebula o, a mixture of gas and dust which stretches across over 500 light-years inside the Orion arm, just 1000 light-years away from the Solar System, in the direction of the Perseus constellation – hence its name. It is the site of plenty young stars, and has attracted the attention of astronomers for decades; therefore Spitzer could not help looking at it with its powerful infrared eyes. Infrared radiations, issued from the dust, generate most of the noticeable glow in the Nebula. Star clusters, like those near the left-hand side of the picture, issue even more  infrared light, and brighten the surrounding clouds, just like the Sun brightens a cloudy sky at sunset. Most of the dust in this area issues little or no visible light (actually, dust blocks visible light), and is therefore more clearly detected with infrared observatories, such as Spitzer.
  • Pinwheel Galaxy
    The Pinwheel Galaxy is a spiral galaxy in the constellation of Ursa Major. You can even observe it with binoculars, because it is one of the brightest galaxies in the whole sky. It looks a bit like the Milky Way, but it is nearly twice its size.
  • Pleiades Cluster
    Also known as the Seven Sisters, this is a beautiful open cluster, which can be seen with the naked eye in the constellation of Taurus. In a city sky, you can  count up to five or six visible stars, whereas with a darker sky, you may count up to twelve stars. All its components are surrounded by light-reflecting nebulae. The Pleiades are not only really near to one another; they are also tied up by gravity, and have a common origin.
  • Rcw 49 Star-Forming Region
    This nebula is one of the most productive star-forming regions in our galaxy. Thanks to the Nasa’s Spitzer Space Telescope, we can see its details, for the first time, in this picture. It is placed 13700 light-years away from the Earth, in the Southern constellation of Centaurus, and contains over 2200 stars amidst the dust. Since many stars in Rcw 49 are embedded in dust plumes, they cannot be seen in visible wavelengths. However, Spitzer works in the infrared, Rcw 49 becomes transparent. It is a bit like smashing a geoid of rock, and finding marvellous quartz spikes inside.
  • Rcw 79 Bubble
    Rcw 79 is a visible nebula in the Southern constellation of Centaurus, about 17200 light-years away from the Earth. The bubble has a diametre of 70 light-years, and it probably took a million years to form, thanks to both radiations and  winds of the young hot stars inside. On the warm edge of the bubble, among gas and dust, new stars formed (and still do). In particular, along the edge of the bubble, you can see at least two groups of young stars:  some of them are visible inside the small bright bubble in the corner – bottom left – whereas another group of baby stars appear near its opening – top right.
  • Rho Ophiuchi
    In this picture, newly-born stars sprout from a blanket of dust of the Rho Ophiuchi Nebula, one of the star-forming regions nearest to our Solar System. The nebula lies near both Scorpius and Ophiuchi constellations, about 407 light-years away from the Earth. Inside the large central nebula, we can find over 300 young stars, whose average age is just 300thousand years: they are therefore very young in comparison with some of the oldest stars in the Universe, which are more than 12 billions years old. The colours in this picture mirror the temperatures of the various stars, as well as the different stages of their evolution: the younger stars  (red) are surrounded by dusty gas discs, from which they are forming. The more evolved stars, which have lost their primordial material, which gave them life, are blue.
  • Rosette Nebula
    The Rosette Nebula is a star-forming region, which looks like a small rose. Because of its beauty, it is one of the most photographed objects of our night sky. In its centre, you can see blue, hot, newly-born stars. The Rosetta Nebula is one of the brightest star-forming regions in the night sky, about 5500 light-years away from us, in the direction of the Monoceros constellation.
  • Serpens Cloud Core
    About 750 light-years away from us, the young stars we can see in this picture are placed inside the constellation Serpens. This group contains only low- or average-mass stars (such as the Sun, for instance), and does not contain massive and bright stars, like the ones we find in larger star-forming regions, such as the Orion Nebula. The red, orange and yellow dots, which you can see at the centre of the picture, are small newly-formed stars. In red, you can also see jets of matter, ejected by these young stars.
  • Sombrero Galaxy
    Its name is due to the fact that it reminds us of the typical hat, used in Mexico for Sun protection. It is one of the most photogenic galaxies, because it appears in profile: its flat disc looks like a frisbee, and its bright halo is due to the presence of billions of ancient stars. It is in the Virgo constellation, and it is three times smaller than our own galaxy.
  • Spider Nebula
    This is the Spider Nebula, an emission nebula in the Auriga constellation. Its name is due to its shape, which is similar to a spider … and spiders scare me.
  • Spitzer Space Telescope
    One of the features of modern Astronomy is the ability to study the light coming from the Universe in all possible frequencies. Some kinds of light can be studied from the ground (visible light, radiowaves), whereas others (X and gamma rays, infrared and ultraviolet rays) need space telescopes. One of these, the Spitzer Space Telescope r, launched by NASA in 2003, and in operation since the start of 2020, allowed us to explore our galaxy in the infrared light, thus making us “see” through thick clouds of gas and dust, and helping us understand star-forming mechanisms better.
  • Tarantula Nebula
    The Tarantula Nebula is a huge H-II region, placed in the Large Magellanic Cloud. It is the largest star-forming region we know in the Local Group of Galaxies. It has been a Supernova explosion site, and its light reached us in 1987: The Supernova SN 1987a, one of the most studied ones, since it is relatively close (it could even be seen with the naked eye, with an apparent magnitude of 4,0).
  • Triangulum Galaxy
    Also known as M33, the Triangulum Galaxy o is a magnificent cosmic object. It is just 3 millions light-years away from the Earth, and is the third galaxy in size and number of stars in the Local Group. M33 does not show a central nucleus, and well-defined spiral arms. Rather, it contains a huge quantity of gas and dust, which favours a quick star-formation, and makes it an object of study on the part of astronomers. It was recently photographed again by the Hubble Telescope, by using the Advanced Camera for Surveys: the result is a record picture, a mosaic of 54 individual images, for a total of almost 665 millions pixels!
  • Trifid Nebula
    The Trifid Nebula is placed in the constellation of Sagittarius, 5400 light-years away from the Earth. Its name is due to the three dark lines of dust clouds which divide it up in three parts, even though this division can be seen much better in a picture taken in the visible, rather than in the infrared wavelength. In the Spitzer picture, we can see bright regions, where new stars are forming. In particular, in the whole nebula, Spitzer discovered 30 huge forming stars, and 120 smaller newly-born stars, both in its dark and in its bright areas. Ten out of 30 large embryos discovered by Spitzer, were found in four dark nuclei, or star “incubators”, where stars are born.
  • W33 Star-Forming Region
    This is W33 Star-Forming region, caught by NASA’s Spitzer Space Telescope Those yellow spots show the growth of a large number of stars. Even though they look so small, they are infact several hundred or thousand times larger than our own Solar System. The stars we see down there are in an intermediate stage of their lives (Let’s say they are grown-up stars), before the stellar wind issued by the stars themselves sweeps away both gas and dust surrounding them, as it happened in the green bubbles with a red core.
  • W5 Star-Forming Region
    It is also called Anima or Embryo Nebula. It is about 7600 light-years away from the Earth, near an open cluster of young, hot, high-mass stars, which can be seen in the constellation of Cassiopeia. In this region, a huge number of stars are forming.
  • Whirpool Galaxy
    The Whirpool Galaxy is one of the brightest and most interesting galaxies in the sky. It is placed in the constellation of Canes Venatici, about 23 millions light-years away from the Earth. It has a diametre of 76thousand light-years. Its mass is about 160 billions solar masses – more or less 10 percent of the mass of the whole Milky Way. It is a part of a small series of galaxies, called M51 group. Most of its intense brightness is due to the presence, in its arms, of young stellar clusters. In the heart of the galaxy, we find a huge black hole, around which everything is rotating. The Vortex Galaxy was the first one whose spiral structure was observed.
  • Witch Head Nebula
    The Witch Head Nebula (IC 2118) is a reflection nebula, placed in the  northeastern area of the constellation of Eridanus, lit up by the bright star Rigel, about two degrees east. Even though Rigel is classified as the second brightest star in the Orion constellation, it is in fact the brightest, exceeding even Betelgeuse. The Witch Head Nebula is about 685 light-years away from us, in the outermost part of Orion’s molecular cloud.
  • Zeta Ophiuchi
    Zeta Ophiuchi is the third brightest star in the Ophiuchus constellation. It is a blue star, 456 light-years away from the Solar System. Its mass is about 20 times the Sun’s, it’s 8 times larger than the Sun, and 90thousand times brighter. Its blue light is weakened by the interstellar dust surrounding it. This star moves very fast: along the direction of its motion, it created a shock front, which can be seen in the infrared as a large bow. The origin of this shock  front can be explained with a mass loss from the star of about one solar mass every nine millions years.

Descriptions by: Silvia Casu, Marco Malaspina, Sara Ricciardi, Maura Sandri, Daniela Vergani, Fabrizio Villa. Translation by Giuliana Giobbi.