I hope you will agree when I say:
Constellations in the sky are a rare sight now but definitely the most pleasing sight.
Constellation can help you sort the twinkling stars scattered across the sky in night to form coherent images which lies deep into your imagination. If you are new to astronomy, you certainly have to overcome the biggest obstacle-learning to identify and see constellations. It can be tricky and difficult to get a hold off but I can assure you the reward is worth glancing at.
The origins of earliest constellation go way back to prehistory. People used to use constellation to convey their stories, beliefs, experiences and mythology. Different cultures have adopted their own constellations some of which still exist in 2000s.
We are going to dig deep into Pegasus constellation today and share mythologies related to it so you have a profound knowledge of this constellation. So make sure to read till the conclusion! Also if you are new to stargazing, this article named “7 Best Constellation Projectors” will be a great help for you to get started with stargazing.
What is Pegasus Constellation?
To all of you who are new, let me define you what constellation is. They are basically a grouping of stars that are imagined to form shapes of objects or creatures in the sky.
According to the listed constellation currently, the constellation of Pegasus is the 7th largest constellation in the northern sky. It is located at 23 hours right ascension and 20° north in declination. The name of this constellation comes from Greek mythology after a legendary white winged horse. Ptolemy, a renowned astronomer, listed this constellation in 2nd century hence it is one of the oldest constellation.
When can you see this beautiful figure in the sky? If you live in the northern hemisphere you can see Pegasus starting from near ending summer and till autumn. However if you residing below the Equator, look for it in late winters till spring.
It is difficult to visualize the figure as an actual horse. This is because the figure is upside down! So make sure to imagine it upside down and you will be able to see the head and the two legs. It is a good practice to have a portable telescope with you for stargazing hence here you go with an article on ‘How To Build A Dobsonian Telescope‘.
Great Square of Pegasus
If you are wondering why this constellation is so famous? It is simply because of the Great Square of Pegasus. The square of Pegasus is an asterism or in simple words group of stars. This asterism consist of four stars namely Markab, Scheat, and Algenib, and Alpheratz. They are categorized as second magnitude stars and have almost the same luminosity. Here you go with a brief information about these stars.
Alpheratz is the brightest star in the square of Pegasus and have an estimated magnitude of 2.06. It is located northeast of the square and the closest of the 4 stars from Earth. The star have a high surface temperature, recorded around 13,800K which is roughly twice that of the sun. Age wise, the star is relatively young, since it only 60 million years old!
The second brightest star in this asterism is Scheat with a magnitude roughly estimated to be close to 2.42. It is a red giant star, located at the upper right corner. The star have been losing mass relatively fastly and consequently the star’s shell have been growing and expanding due to gas and dust accumulated around it. Comparing it with sun’s temperature, it is cooler with only 3,689K measured.
Third brightest star in this asterism is Markab having apparent magnitude of 2.48. Markab is categorized as an A-type subgiant star with a radius 472 times larger than of sun. It is very hot, with temperature around 9,765 K at its surface.
Lastly, Algenib. It is the most of distant star in this asterism with the magnitude of 2.84. It is southeast corner of the asterism and almost 4x times hotter than sun with a temperature recorded 21,179K.
There are numerous interesting stars in this constellation, among them are the brightest star Enif, Homam, the red dwarf and white dwarf system named as AG Pegasi, the white star Salm, Phi & Psi Pegasi and 51 Pegasi.
Also known as Epsilon Pegasi, is the brightest star in the whole constellation. It have a magnitude of 2.399, however, the magnitude is very irregular and can vary between 0.7 to 3.5 in magnitude. It is classified as a K-type orange-hued star, and despite living only a few million years it has entered the supergiant stage and it have only few million years left before it life cycle ends. Though astronomers aren’t certain if the star will explode in supernova form or end its cycle as a neon-oxygen white dwarf.
The star have an estimated age of around 2o million years and is cooler than Sun with a surface temperature of 4,379. Although cooler, the star is more than thousand folds brighter than the sun.
It is designated as Zeta Pegasi and is 204 light years away from our solar system. It have a magnitude of +3.414 and pulsate B star. Comparing with Homam, sun have 322x times less mass, 403x lesser radius than Homam , and it is 224 times less brighter than Homam . Furthermore, the star is twofold hotter than sun, having temperatures of around 11,190 K.
A symbiotic binary star system which is located near the brightest star, Enif. Since it is a binary star system it has a magnitude of 9.4. The star is classified as symbiotic nova due to the nova outburst it experience in 1885 and consecutively smaller outburst which resulted in its magnitude to grow.
Unlike other stars, it is cooler than our sun having temperature of about 3,650K. However, the star is 250 times the mass of our sun and 1,150 times brighter.
Salm is categorized as an A-type main sequence star and the location of this star can be explained in term of relative distant from Earth. It is approximately 162 light years from Earth. The apparent magnitude(how bright we see the star from earth) is close to +4.58 which is quite bright.
Salm appears to be blue-white in color and the surface temperature estimated by the astronomer lies between 7,500-10,000K . The star have bigger radius than our sun and is very luminous. The radial speed recorded lies close to 15.2 km per second making it a fast-spinning star.
Phi & Psi Pegasi
They are two red giants stars which are located around 460 and 480 light years away from Earth. Phi and Psi have apparent magnitude of 5.107 and 4.66 respectively.
Phi Pegasi is 200 times bigger than our sun and 960 times brighter can our sun. However, it is cooler than the sun with temperature calculated around 3,882K.
It is one of the star in this constellation which looks like a sun. The prominent feature about this star is that it is first main-sequence star discovered which confirms to have an exoplanet orbiting around it. Fascinating right? The star have almost same temperature of that of sun however it is more luminous. It is estimated to be 6.1 billion years old.
Although it have a low visibility index of around 5.49 from Earth. It is still visible to the naked eye and you can see it!
The Square of Pegasus is a great way to explore and find different deep sky objects. On the top of the list of famous deep sky objects are The Andromeda Galaxy, the Triangulum Galaxy, and the Great Pegasus Cluster.
The Andromeda Galaxy
The Andromeda galaxy is twofold the size of our milky way making it the largest galaxy in the Local Group.. It is four times larger than milky way and it is estimated to host around 4 trillion stars.
It have a unique structure with a black hole in its center and have blue stars in the disk at its radius with a ring of older red stars surrounding the disk. It is estimated to have a collision with milky way in around 4.5 billion years.
The Triangulum Galaxy
It is also designated as Messier 33 and can be found opposite to Andromeda galaxy. It is a spiral galaxy 2.73 million light years away from Earth. The Triangulum Galaxy takes the third position in Local group of galaxies, after our Milky Way and the Andromeda Galaxy. It is fascinating that despite being one of the most distant permanent objects, it is visible by our bare eyes.
The Great Pegasus Cluster
It is designated as Messier 15 and can be observed near the brightest star Enif. It is estimated to be in existence for around 12.0 billion years which without a doubt makes is one of the oldest globular clusters discovered by humans.
The Cluster is approximately distant 33,600 light-years from Earth with an enormous diameter calculated of 175 light-years. It has an absolute magnitude of −9.2, which translates to a total luminosity of 360,000 times that of the Sun.
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