Some Stars in Milky Way Could be Stolen

Assessment 15- Milky Way Galaxy

https://cosmosmagazine.com/space/distant-stars-in-milky-way-may-be-stolen-from-another-galaxy

This article from cosmosmagazine.com talks about how two astrophysicists from Harvard have found that the Milky Way has stripped a few stars from the Sagittarius dwarf galaxy, which orbits the Milky Way. The Milky Way is a barred spiral galaxy. A barred spiral galaxy appears like a spiral, with a bar running through the middle, with a flat rotating disk made up of spiral arms around it. Our galaxy has four spiral arms. The size of the Milky way it also pretty huge, being 100,000 light years across. We saw this in a powerpoint slide in class that showed the massive size of the Milky Way.


 

I learned a lot from this conceptual objective given I knew little about the structure and size of the Milky Way Galaxy previously. I was surprised at how massive the Milky way really is. 100,000 light years is far greater than I expected.

New Type of Galaxy Discovered

Assessment 16- Other Galaxies

Article link from sciencealert.com
Article link from space.com

Scientists have recently discovered a new type of galaxy. PGC 1000714 appears to be a normal ring galaxy, consisting of a ring of stars around a galactic core. But this galaxy actually has two rings, the first time a galaxy like this has been observed.32894679-ring-galaxy-1.jpg

This galaxy is, in appearance, much different than our Milky Way, which is a barred spiral galaxy. A barred spiral galaxy appears like a spiral, with a bar running through the middle. This is different than PGC 1000714, which has uniform rings around it. This newly discovered type of galaxy is also much more rare, as only about 0.1 percent of galaxies, according to sciencealert.com, are ring type galaxies. Spiral type galaxies are much more common, being the most common type of large galaxy.


 

I learned a lot about the Milky Way and other types of galaxies from this conceptual objective. I didn’t know much of anything about the structure of the Milky Way, and how it is similar and different than other types of galaxies. This article surprised me that we are still discovering new types of galaxies.

 

Cheers to our Ever-Growing Universe

In recent space news, I cam upon an article on space.com about photographing a black hole. Apparently, scientists are attempting to capture a better image of the black hole at the center of our galaxy. With the help of at least 7 different observatories around the world, scientists are hoping to determine the mass, spin, and other regular characteristics exhibited by black holes in hopes to learn more about them. This idea of scientists pointing their telescopes at one area for an extended period of time reminds me of the story Dr. Morrison explained on the last day of class about the Hubble space telescope and how in doing so scientists came to the miraculous discovery about our universe.

Astronomers know the universe is expanding because when they look out into dark space where they expect nothing to be, they find more galaxies. In class discussion about the Hubble space telescope, there was a story mentioned about a man who pointed the telescope at an area of the sky that was in complete darkness for 10 hours over the course of 10 days. This picture ended up becoming more than just a blank, black screen. It became this:

This image is the product of Hubble staring at black space for 100 hours. It was explained in class that the reason for this image to appear is due to the expansion of the universe. If the universe wasn’t expanding, then the blank space would remain blank when studied further. However, since every blank space is constantly being filled at a distance, scientists believe that the universe is constantly expanding. Also, the knowledge we have about the age of our universe lends a hand in explaining why the universe is expanding as well. Since observing space is like observing time pass (due to the distance and time it takes light to travel to us), we can go all the way back to the first things we can see; These items are the oldest and we cannot look any father past them. Since we cannot look father, this must mean that their existence marks the age of our universe (roughly 13.7 billion years). After some time there was a period of darkness, then stopped by the light of our first stars for about 400 million years. From then, that universe has been growing because new items are being created. That is how we know that the universe is getting larger. If we were to look out and see only older stars, galaxies, and planets we could assume that the universe is staying constant. However, since when we look out we see new items in the “dark corners” where we presume nothing is, then that must lead to the truth of universal expansion.

I find it crazy to believe we are such a minuscule part of this life. In class discussion of the Pale Blue Dot, I lost myself in thought of what is out there and what can come to being. Other sciences can tell you direct specifics about our life, about chemicals, and physical properties, but the wonder that astronomy has to offer is unmatched. Its absurd to think that we might not know the purpose of our existence, if we are indeed one in billions, or if there is something greater out there…. But we keep on looking up. Not only is that poetic, but it is inspiring in our humanly conquest to keep moving on even if we do not know whats ahead. We move blindly through our solar system, our galaxy, and our universe and our life. And with that, I just have to say here’s to at least another 42 billion years of us searching for the answer to life, the universe, and everything.

Source: space.com

Artful Anomalies

In recent space news, a supernova that has been spotted in our night sky has been found illuminated and enhanced by galaxies causing it to show up in our night sky in four separate spots. This discovery has lead me to question how other galaxies relate to our own.

In class we learned about different types of galaxies in comparison to our own. In a Lecture-Tutorial on Galaxy Classification, we looked at two different types of galaxies, elliptical and spiral, along with their characteristics. To begin with, our galaxy is a spiral galaxy and is greatly related to other galaxies of this type. Spiral galaxies are large, flat disks usually blue in color caused by gas and dust particles that make new star formation possible. They are distinctly known for their arms and cloudy appearance. Oppositely, elliptical galaxies are circular, smaller galaxies generally red in color due to having no new star production and being composed of mainly low-mass, red stars. These galaxies are generally a lot older than spiral galaxies, and inferring from the Lecture-Tutorial, may even be result of a galaxy in its old ages.

A little off topic, but in my reflection of completing this objective, I wanted to admire space a little. As an artist, I find space extremely beautiful and I would like to recreate pictures I see of them. Essentially, space is my muse at this moment, and I plan on creating some very detailed painting of galaxies and space occurrences that I find phenomenal. What really interested me on this objective was actually getting to learn the distinct differences about these galaxies. Art to me is best made when someone is enveloped in the idea and becomes an expert with an understanding beyond the object that is on the canvas. I have been waiting all semester to understand what galaxies are and how to accurately portray them, so this objective really struck with me and I will probably refer back to it when I am making art.

Source: space.com

Star Lifetimes and Energy Production

I found an article at,  http://www.space.com/22471-red-giant-stars.html     . It talks about how the red giant star is a star that is dying. It reaches a size of 100 million to 1 billion kilometers, which is 100 to 1,000 times the size of today’s sun. It’s because the energy is spread across larger areas. The surface temperature reach up to 2,200 to 3,200 degrees Celsius. Stars spend approximately 3,000 to 1 billion years as a red giant. The star shrinks until a new helium shell reaches the core.

When the helium ignites, outer layers are blown off in huge clouds filled with gas and dust which is called planetary nebulae. The core collapses on itself and the smaller stars such as the sun end their lives as white dwarfs. The sun will begin the helium-burning process which takes place in around 5 billion years.

After it expands, its outer layers will consume the planets, including Earth. When stars turn into red giants, it can actually become habitable for other planets. Habitable zones is a region that water can exist in. A red giant can exist for a billion years which is a possibility that life can form. My personal opinion of this article is overall good because it has a lot of interesting facts. I would recommend people to read it. This article connects to what I have learned in class because it talks about the stars lifetimes and energy production which is what we went over in class. I learned in class that most energy released by fusion starts its journey out of the solar core in the form of protons. The clicker questions also helped out.

Make Way for the Milky Way

In recent space news, I learned about scientists creating clear animations that can predict the evolution of our galaxy and the movement it will take over the course of the next 5 million years. Since all this prediction is based on preconceived knowledge on our galaxy collected by scientists over the years, I thought it would be nice to discuss what I have learned about our galaxy in class in the light of this new scientific discovery.

Image result for milky way stars on the move- satellite data

In lecture, we discussed the properties of our galaxy, the Milky Way. This galaxy is a flat, disk-shaped, spiral galaxy with a bright bulge in the center. It is composed of dust, gas, and billions of stars. Our solar system is located halfway out from the center bulge to the edge of the disc. The shape of our galaxy reflects the way stars move within it. Each of the 4 arms has hundreds of thousands of stars (understatement) that make them up. These stars are younger than those that make up the center bulge, which are all really old stars that have lived out their stellar lives already and spend their years as low mass, red stars. Within the arms, new stars are continuously being formed, while the bulge-bar at the center of our galaxy has no new star production. At the very center of our galaxy sits a black hole, and surrounding the outside of our galaxy in a spherical shape, is a vast halo filled of very old stars.

I find the information on our solar system to be most exiting because astronomers have found out so much just from observing within our own galaxy. What happens when we are able to go father? Also, having an understanding of our solar system is one step to understanding other solar systems, which leads to even more SCIENTIFIC DISCOVERY!

Source: space.com

Pick on Some-Star Your Own Size!

In a previously mentioned conceptual objective, I wrote about astronomers that found a black hole within a globular cluster tearing apart a white dwarf. This gruesome action was completed without remorse for this already dead star. As discussed in this lecture, white dwarfs are the results of low mass stars, much like our own, that burn up all their energy from nuclear fusion and later eject their outer layers and leave behind this small, compact star in its place. I wanted to take the time and appreciate this article from another point related to its subject.

In lecture, we covered material on how stars live out their lifetimes. Beginning with a cloud of gases, gravity pulls particles in until the star can create its own energy through nuclear fusion. Stars with higher mass contract into less space before fusion because they needed higher core temperatures to form and in turn became larger in radius, greater in luminosity, and hotter on the surface, causing them to live shorter than the sun. Meanwhile, smaller stars in the main sequence needed lower temperatures to begin nuclear fusion, making them smaller in radius, lower in surface temperature, lower in luminosity, and lower core temperature, causing them to exhaust their fuel much slower than our sun and stars larger than it. According to this article, the star that was being ripped apart brutally was one of such stars with a low mass. When it comes to star evolution and death, there comes a point in which a star will exhaust out of fuel. This stage is marked the star becoming a Red Giant, as its core shrinks due to the exhaustion of hydrogen atoms and its outer-layer to expand due to hydrogen shell fusion within that area. Once a star hits this stage, a few things can happen. In a Lecture-Tutorial we completed in class, we learned that that a small mass star ejects its outer layers creating a planetary nebula and leaves a white dwarf at its core. Oppositely, a red giant with a large mass will cause a supernova, and, depending on the original mass of the star, will either leave behind a neutron star (if small mass) or a black hole (if large mass).

In comparison to the article, I find it ironic that the small white dwarf was potentially picked on by what was left over by the death of a star much larger than it. I feel like if the stars were equivalent to people, then the black hole is a melodramatic bully that feels like they have to suck the life out of others to survive. Talk about high school drama in the sky, am I right?

Source: Bad Astronomy