Meanwhile, it is 2. We can also call it Andromeda VI. This M31 satellite galaxy has an apparent magnitude of The stars in this dwarf galaxy are mostly metal-poor.
Though it may seem like a scary event, this collision will happen far beyond our lifetime, 4. Studies also indicate that because galaxies are mostly empty space, it is unlikely for stars to collide with each other. That said, the Solar System will not be adversely affected. Even if, say, the Solar System is safe from the collision, life on Earth would have long ended. That is because the Sun would have become so hot at that time.
Our planet would dry out and terrestrial life will be no more. Still, all those events are way too far in the future. Now that we know everything about the Andromeda Gallaxy, it is important to know when and where to find it in the night sky. The first thing we need to do is find the constellation of Andromeda the Chained Woman.
It is mostly seen in the northern hemisphere during the autumn months. By that time, it is spring in the southern hemisphere. We can easily see the Andromeda constellation because it is surrounded by other famous constellations of Perseus, Cassiopeia, Lacerta, Pegasus, Pisces, and Triangulum. One of the easiest patterns to see in the night sky is the W shape of Cassiopeia. The vertices of this W will point you to Andromeda. It is also along the line of Mirach Beta Andromedae , the second-brightest star in the constellation.
Andromeda has inspired a constellation to be named after her, as well as a galaxy. But who is she in Greek mythology?
Andromeda was a beautiful Ethiopian princess. Her parents were King Cepheus and Queen Cassiopeia. One day, the queen proclaimed that she is more beautiful than the Nereids sea nymphs. The sea nymphs hear what the vain queen said, and they were offended by it. Even Poseidon, the sea god, was mad too!
The angry god sent the monster Cetus to the kingdom of Ethiopia. King Cepheus became very worried so he consulted the Oracle of Ammon. King Cepheus followed the advice and let his daughter be chained to a rock, awaiting her death in the hands of the savage sea monster. Luck smiled at princess Andromeda because the hero Perseus unchained her killed Cetus the sea monster. Perseus later married Andromeda and they had children together. In honor of Andromeda, the goddess Athena placed her in the night sky for everyone to see.
Even after death, she remains close in the sky with her loved ones who also became the constellations of Perseus, Cassiopeia, and Cepheus.
Facts about the Andromeda Galaxy The Andromeda Galaxy gets its name from the area in which it appears, the constellation of Andromeda — which is named for the after the mythological Greek princess Andromeda. Andromeda is probably the most massive galaxy in the Local Group. This is contrary to previous research which speculated that the Milky Way was the most massive because it contained more dark matter. There are around 1 trillion stars in the galaxy, compared with the Milky Way which has around billion.
In approximately 3. A team of astronomers in believe that M31 was formed between 5 and 9 billion years ago when two smaller galaxies collided and merged. The Andromeda Galaxy has an apparent magnitude of 3. The microlensing event PAN2 hints at the existence of an extragalactic planet.
It is estimated to be 6. If proven, it would be the first exoplanet to be known that is outside the Milky Way. Globular cluster system : Messier 31 has an abundant globular cluster system, similar to the Milky Way.
Observations of stellar velocities in Mayall II by HST suggest that a 20, solar mass black hole may exist in its centre. Credit : Rich M. Columbia University , Freedman W. The universe's largest-known galaxies—giant elliptical galaxies—can contain up to a trillion stars and span two million light-years across.
Elliptical galaxies may also be small, in which case they are called dwarf elliptical galaxies. Elliptical galaxies contain many older stars, but little dust and other interstellar matter. Their stars orbit the galactic center, like those in the disks of spiral galaxies, but they do so in more random directions.
Few new stars are known to form in elliptical galaxies. They are common in galaxy clusters. Lenticular galaxies , such as the iconic Sombrero Galaxy , sit between elliptical and spiral galaxies.
Like elliptical galaxies, they have little dust and interstellar matter, and they seem to form more often in densely populated regions of space. Galaxies that are not spiral, lenticular, or elliptical are called irregular galaxies. Irregular galaxies—such as the Large and Small Magellanic Clouds that flank our Milky Way—appear misshapen and lack a distinct form, often because they are within the gravitational influence of other galaxies close by.
They are full of gas and dust, which makes them great nurseries for forming new stars. Some galaxies occur alone or in pairs, but they are more often parts of larger associations known as groups, clusters, and superclusters.
Our Milky Way, for instance, is in the Local Group , a galaxy group about 10 million light-years across that also includes the Andromeda galaxy and its satellites.
The Local Group and its neighbor galaxy cluster, the Virgo Cluster , both lie within the larger Virgo Supercluster , a concentration of galaxies that stretches about million light-years across.
The Virgo Supercluster, in turn, is a limb of Laniakea, an even bigger supercluster of , galaxies that astronomers defined in Galaxies in clusters often interact and even merge together in a dynamic cosmic dance of interacting gravity.
When two galaxies collide and intermingle, gases can flow towards the galactic center, which can trigger phenomena like rapid star formation. Our own Milky Way will merge with the Andromeda galaxy in about 4. Because elliptical galaxies contain older stars and less gas than spiral galaxies, it seems that the galaxy types represent part of a natural evolution: As spiral galaxies age, interact, and merge, they lose their familiar shapes and become elliptical galaxies. Using supercomputers, scientists can look back in time and simulate how a galaxy may have formed in the early universe and grown into what we see today.
Scientists estimate the age of the universe at Because the deeper you look into space, the further you see back in time, we can conclude that galaxies several billions of light-years away formed fairly soon after the big bang. While most galaxies formed early, data indicates that some galaxies have formed within the past few billion years — relatively recently in cosmic terms.
The early universe was filled mainly with hydrogen and helium, with some areas slightly denser than others. Gravity caused the gas in these clouds to collapse and form the first generation of stars. These first stars rapidly burned out.
Gravity continued to collapse the clouds. As other clouds came close to each other, gravity sent them careening into one another and knitted the clouds into larger, spinning packs. As the clouds further collapsed, they became rotating disks, which amassed more gas and dust. New stars formed, creating extensive spiral arms filled with colonies of stars. Sprinkled along the periphery were globular clusters, along with a halo of gas, dust and dark matter.
While Hubble is unable to see the very first galaxies, it can track the development of galaxies over much of cosmic time. The series of Hubble Deep Field images and other deep surveys have uncovered galaxies at many different distances out in the universe, and therefore at many different times in their development.
Farther galaxies, seen earlier in time, have less developed structure. Nearer galaxies, seen later in time, grow to resemble the familiar galaxy shapes we see in the local universe. The Building Blocks of the Universe. On This Page. Types of Galaxies. What Kinds of Galaxies Are There? This graphic compares illustrations of the three main types of galaxies top with actual photos of galaxies bottom that fit the categories. Credit: A.
Feild STScI. Dark Matter. What Is Dark Matter?
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