Every person who lives on this planet has seen a falling star, also known as a shooting star. I confess i sincerely believed such was the case that these were on fact, stars much as I believed in Santa Claus.But I heard the shocking truth; these or not, in fact,stars. When peering into the sparking emptiness of the night sky, I watched as another meteoric body, for the umpteen-billionth time, tried to ram through the earth's atmosphere. This happens constantly, day in day out. Millions of cosmic bodies hurl themselves towards the surface of our planet every day. There is nothing very special going on here. So despite the apparent absurdity of the phrase: look look a falling star!! It turns out that real falling stars do exist in our universe fasten your seabelts,ladies and gentlemen once again we seeing information in deep space .
Meet Mira or it is also called Omicron Ceti a sizeable star itis 700 times longer than the diameter of our sun. It is an even stranger and more surprising star than Beteleguse, the heroine from our last installment. The first mention of this beauty is found in hipparchus in 134 B.C, as well as in the testimonies of Chinese astronomers later in the year 1070. But it's almost supernatural properties were discovered only recently pastor/ astronomers David fabricius quite by chance, and without realizing it, discovered a new type of star on the morning of August 13, 1596. At that time, he was just watching Mercury or rather he was going to measure the angular distance from the planet to the star glittering nearby of an apparent magnitude of 3 in the constellation of Cetus.
 |
| Image by|Google |
Interestingly,he had never come across it before,and it was also notably absent from all the stealer maps and globes,though of course,maps and globes were not as accurate in olden days. The disregard for some not very bright star was commonplace.fabricius began to keep an eye on the stranger and lo and behold brilliance grew right up of magnitude of 2 and it became the brightest star in its constellation by the end of the August. But then in September,the star faded and by mid October,it had disappeared completely. If fall confidence that this was a different,new star fabricius stopped observing but to his great surprise he came across the great mysterious traveler 13 years later on February 15th,1609. But to be fair, astronomer Johann Bayer managed to notice it about 6 years before this in 1603. He entered the data into his famous star atlas but had not yet suspected the super properties of this find. By the way,by that time the star had already reached a stellar magnitude of 4. Closely monitor omicron seti for next several decades so for example,the polish astromere Jun hevelius who observed the stealler body from 1659-1682,called it Mira,which is from latin and translate as "amazing" and he was absolutely right. This star is amazing. Usually it is so dim that it is quite difficult to see with even a small amateur telescope but due to its peculiarity it become the brightest star in the constellation saetus at certain times. Then it's called "peaks".
Then it fades again and becomes almost invisible and then again and again everything reapeats. Scientists finally, by the middle of the 17th century. Established that his miracle represented a new type a variable star with a very long period of brightness and very large amplitude. To put it simply, Mira is a star that constantly changes its brightness but it happens with a fair bit of irregularity. The glitter of star,for those who do not know is its apparant Stellar magnitude. The same as luminosity or ever simpler, brightness. Using the astronomical scale smaller number are brighter . The brightness of Mira increases three and half times in just 332 days. From a brightness of magnitude 10,when it is almost invisible, in a telescope up to magnitude 2. When it become the brightest in its constellation as i said there is no pattern to her behaviour. As a matter of fact,the period and range of brightness changes and is completely unstable . One time omicron seti went from the relatively dark 9th magnitude and then increased to the 5th and then back again. Another time,she faded to the 10th magnitude but then shot up to her maximum brightest magnitude of 2. As you can see,the fluctuation in luminosity are simply immense. But what is eat that mean? The luminosity of omicron seti, aka Mira at the minimum of its brightness almost corresponds,or is even slightly less than, the luminosity of our sun. That means then, that at the maximum the brightness of Mira will surpass that of our sun by 700 times and sometimes by as much as 1500 times the brightness of our sun.
 |
| Star Mira A|image by Star Facts |
The whole point this is : when redgiants pulsate,the temperature of their surface also changes, which immediately affects the optical properties of the stellar atmosphere. As the temperature rises, the chemical compounds decompose, and the atmosphere becomes more transparent also a considerable role is taken by the hot hydrogen masses. Which erupt into the atmosphere during the period of maximum brightness of the star. At least, this is the most plausible explanation which i have managed to unearth of the amazing changes that regularly occur with Mira seti.
Thank you
0 Comments