Strange Secrets Of Star Birth Revealed By Andromeda


All of the billions and billions of stars that set our Milky Way Galaxy on fabulous fire with their blasts of magnificent light, were born as the result of the gravitational collapse of an extremely dense, frigidly cold glob embedded within a gigantic and ghostly, billowing, dark molecular cloud. These frigid clouds composed of gas and dust serve as the strange nurseries of baby stars and they are scattered throughout our Galaxy in huge numbers. But, even though all stars are born the same way–and not in isolation–they are not all the same, and they can vary in mass by more than a factor of 1,000. The question is what fraction of stars that precipitate out from the undulating folds of these phantom-like, pitch-dark clouds–that are composed primarily of frigid hydrogen gas–are born in clusters that harbor blue giants, yellow dwarfs, and red dwarf stars? In September 2015, astronomers using the Hubble Space Telescope (HST) reported their findings that, for whatever reason, Nature apparently cooks up stars as if they were “batches of cookies”–and there is a consistent distribution from massive stars to small stars. The astronomers were surprised to find that this ratio is the same for both our own Milky Way and the neighboring large spiral Andromeda galaxy, given the complex physics involved in stellar birth.

Therefore, the best way to answer the question is not to search all over our own starlit, spiral Milky Way Galaxy–because we are inside of it–but to look far out into space to our neighboring Andromeda galaxy (M31)–where we can be on the outside looking in!

In a survey of HST images of 2,753 youthful, blue star clusters inhabiting Andromeda, the team of astronomers found that M31 and our own Galaxy have a similar percentage of neonatal stars based on mass. By determining what percentage of stellar inhabitants possess a particular mass within their natal cluster, or the Initial Mass Function (IMF), astronomers can better interpret the light traveling from distant galaxies, which can help them to gain an understanding of the formation history of stars throughout the entire Universe.

The detailed survey, constructed from 414 HST mosaic images of M31, was conducted by a collaboration between astronomers and “citizen scientists”. The “citizen scientists” were volunteers who provided valuable aid in analyzing the enormous amount of data from HST.

“Given the sheer volume of Hubble images, our study of the IMF would not have been possible without the help of citizen scientists,” commented Dr. Daniel Weisz in a September 3, 2015 Hubblesite Press Release. Dr. Weisz is of the University of Washington in Seattle, and lead author on a paper that appeared in the June 20, 2015 issue of The Astrophysical Journal. 바카라사이트

“All Stars Are Not Created Equal”

Our dazzling, luminous Star, the Sun, is a solitary stellar inhabitant of our Galaxy; classified dismissively as a petite yellow dwarf. Even though our Sun is now a lonely ball of fiery, roiling, mostly hydrogen gas, it has not always been so bereft of others of its sparkling kind. Our Sun was likely born a member of a dense open star cluster along with literally thousands of other glittering sibling stars. It is generally thought that the neonatal Sun was either hurled out of its birth-cluster or it simply floated away from its stellar siblings about 4.5 billion years ago. The long-lost brothers and sisters of our Star have long since also wandered away to more distant regions of our Galaxy–and there very well may have been as many as 3,500 of these starry travelers. Perhaps our Star’s birth cluster started out with about 500 to 3,000 solar-masses and a diameter smaller than approximately 20 light-years–which is typical for open clusters.

Our Solar System formed out of the wreckage of jumbled fragments that were the lingering relics of the nuclear-fusing, but now long-dead furnaces, of earlier generations of stars. Our Sun (like its lovely siblings) was born within a frigid, extremely dense blob that was lodged within the billowing folds of a dark molecular cloud. In the secretive depths of these enormous clouds of mostly hydrogen gas, fragile threads of material gradually merge, clump together, and then grow for hundreds of thousands of years. Then hugged mercilessly by crushing gravity, the hydrogen atoms within this clump suddenly fuse, lighting a fire that will burn with furious, dazzling light for as long as the new baby star lives–because this is how all stars are born.

 


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