Articles “New Stars Discovery Shed New Light on Galaxy’s Formation” https://www.sciencedaily.com/releases/2016/11/161125145015.htm, “The Size of the Milky Way” https://www.universetoday.com/24182/the-size-of-the-milky-way/
In the first article “New Stars Discovery Shed New Light on Galaxy’s Formation” explains the recent discovery of a family of stars that are close to the core of our galaxy, the Milky Way. Scientists are saying that these stars could give us an insight into our galaxy’s early stages of life and the origins of globular clusters. How they found these stars was by using infrared light towards the center of the galaxy. One scientist in this article explains how this new finding will help us to address the question of how the nature of the stars from the inner region work and how they survived the chaotic formation of the galaxy’s core. This story very much relates to the topic of this unit about our Milky Way galaxy. So the question stands What exactly is a galaxy? Well according to the Dictionary, it is “a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space.” Our galaxy is exactly this but it’s much more than just a bunch of stars, dust, and an invisible pulling force. It is our home and a proper home has warmth, space to move, and a family to be part of.
According to the second article “The Size of the Milky Way” our galactic home is a large spiral galaxy that has been around for 13.21 billion years that is measured accordingly in units to the mass of our sun and is the equivalent to 3 trillion in mass of them. In class we talked about how the Milky Way is not only large when it comes to mass but also its width and depth. The galaxy is approximately 1oo,000 light years across and around a 1,000 light years in-depth. If you were to travel just to the core of our galaxy from Earth (which isn’t even at the farthest edge) you would have to fly at the speed of light 27 to 28 thousand light years. It would long exceed the span of a lifetime.
So how were we able to get these measurements and know what our galaxy looks like? Lets look at what we learned in class in order to get the answer. Since we can only see the Milky Way from where we orbit in our own solar system within the galaxy, it is hard to measure the distance of what you can not fully see. It is like figuring out your house by only staying in and seeing one room. Scientists however have come up with a system to solve this problem by measuring the distance to globular clusters and the distributions of hydrogen gas in the disk like parts of the galaxy. This has proven to be the most accurate way of measurement. Size however is not the only thing that matters. In order to get a better understanding of our galaxy we must also look at its structure. Our galaxy has many features to it that are similar and different to other galaxies. Like other Spiral galaxies the Milky Way has a bulge, halo, disk, and spiral arms that are all made up of materials such as stars, gases, and dust. At the bulge of our galaxy also known as the core, has the least mass of the rest of the galaxy because of the stars surrounding its motion. The mass is 2.6 million Msun. You will have a hard time seeing the center however because the dust from the disk obscures the view. The best choice to view the bulge is by using radio waves. The halo of the galaxy largely consists of individual and clusters of old stars these stars are called globular clusters as mentioned earlier. However there is more to the halo than just clusters. There is an unknown matter that we have yet to figure out called “dark matter”. This material we cannot see but we can still measure its gravitational effect. In total the halo is estimated to be over 130,000 light years across. Just as big if not bigger than the galaxy itself which is pretty impressive. Next we have the disk which is the flattened area that surrounds the core or bulge in a galaxy. Shaped similarly to a spiral pancake if you were to cut pieces off, it contains mostly young stars, gas and dust, that are mostly within the spiral arms. There are some old stars present as well. Lastly we have the spiral arms of the galaxy which are the spindly like tentacles of the spiral galaxy. These pin wheel shaped features of the galaxy generally contain a lot of gas, dust, and young blue stars. This unique characteristic is only found in spiral galaxies.
I learned a lot from this objective especially with the parts of the galaxy and what is in them. I knew for a while now some of the parts but not all of them. I knew about the core and the disk mostly but not some of the information I learned about the spiral arms or especially the halo. It was definitely an experience for me and I enjoyed learning about it. It will help with future blog posts for sure and just in general expanding my knowledge. I also enjoyed both of the articles I read for this unit. I feel that the news story related well with my blog post and helped to get my point across to those reading. Both of the articles were also written well enough for anyone to understand which was good. All together this was a good lesson and each one gets all the more interesting. I am looking forward to our next objective.