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

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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

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

A Hungry Black Hole has no Remorse

In recent space news, astronomers 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 a later 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. This article had me thinking about the process in which a star must maintain equilibrium before its death, whether it be by virtue of running out of fuel or gravity pulling it into a black hole.

artwork depicting 47 Tuc X9

In class we discussed the topic about how stars live and maintain energy. This process is referred to as nuclear fusion. When a star is created from a solar nebula, gravity pulls the cloud of gas in, shrinking its size, causing temperatures to rise, and upon building up to a dense core, gravity created a protostar. Once a protostar is created, gravitational contraction continues until a star can maintain nuclear fusion. The process of nuclear fusion is the action in which hydrogen atoms bind to each other in order to maintain energy. In order for a star to survive, it must maintain equilibrium between creating energy in its core and releasing it into space, also referred to as energy balance. Without this, the balance between pressure and gravity will not remain steady and will cause the star to collapse on itself. Thus, stars continuously bind hydrogen atoms, making new elements and releasing energy, while gravitational equilibrium monitors the change in temperature and causes the increase or decrease of nuclear fusion.

When reflecting upon star life and deaths, I see them as a balancing act that eventually tips a scale and causes an end. For example, the force of the black hole pulling in this white dwarf is much stronger than the force keeping the star in balance, but unlike actual death on this planet, the stars particles have a potential of being recycled and becoming something new. The way things “die” in space is not as much gruesome as the void makes it out to be.  This idea gives me hope for another life I guess, not to become all spiritual but life is just an overall interesting topic to talk about with people. we all want to know. Is recycled life a possibility? In our lifetime, I guess we’ll never know.

Source: Bad Astronomy

H-R= Hella Rad!

In the history of this course, this conceptual objective had to be my favorite one. In class, we learned that the HertzsprungRussell diagram classifies stars based on their luminosity, temperature, spectral type, and absolute magnitude. When it comes to classifying and understanding stars, scientists use the H-R diagram in order to compare them to other stars they are related to. Just so we’re clear, the H-R diagram separates stars into 3 major categories: main sequence, red giants, and white dwarf stars. In each section, stars share certain commonalities. With these stars clustered, scientists can make observations on star types and star lifetimes to further understanding on composition and what will happen to these stars in the future. The H-R diagram is also like a timeline, because it shows information about stars throughout their life cycle. This diagram can also show relationships between the radii of the main sequence, which ranges from small sizes in the lower left with high-temperature, low-luminosity stars to the large sizes in the low-temperature, high luminosity stars in the upper right.Image result for HR diagram

What I like most about this objective is that it basically brings together all the ideas we have covered in lecture about stars throughout the semester into one easy to understand diagram. When going back on past objectives where I talked about the Castor and Pollux, two stars that make up the constellation Gemini. These stars as I have explained twice before, display very different qualities, one of which is the type of star they are, Pollux being a Red giant, and Castor being a “star” made up of 3 binary star systems working together. Within these 2  stars (or 7 to be exact), an understanding development can be made based off of just one or two known properties. What I also enjoy is the amount of doors of understanding opened by this diagram. It takes knowing one or two qualities to understand the whole star. For example, Pollux, which is actually located on the diagram above as well, is a red giant. Within knowing this classification, one can assume that it is larger, more luminous, and cooler than our sun just by looking at this diagram. When given specific information, such as Pollux being 100 times more luminous than our sun, we can use this information in conjunction with its apparent luminosity to figure out the distance to our Earth. Overall, I believe this to be a revolutionary find for astronomers and glad this diagram was created because it makes understanding outer space easier. Thanks science!

Source: Twins again, I’m sorry

Going Back to the Twins

In a past conceptual objective, I have discussed the the existence of two stars that make up the constellation Gemini, Castor and Pollux. Just as a recap: these two stars, well actually one dying red giant and the other the product of three binary systems (you hear that, 6 stars for the price of one!), display different qualities that are explained thoroughly in the article. However, information shared in class about luminosity and temperature lead me down the path of deeper understanding. Today I will be revisiting this article within a different focus, distance, size, and mass.

During lecture, we discussed how scientists study the properties of stars including the distance, size, and mass. When accounting for the distance of stars, we learned, in the Lecture-Tutorial on the Parsec, that scientists use telescopes to determine the parallax angle, which is the smallest angle created in the right triangle between the Earth, Sun, and the star whose distance you are measuring. First, scientists observe a star in the night sky which goes through parallax in our night sky. Parallax is defined as the apparent motion of nearby objects relative to distant objects. On Earth, objects also experience parallax. For example, in class we mentioned how if we place a finger in front of our nose, close one eye, and then switch which eye is closed, we can observe parallax. The finger’s position has not actually changed; However, when observing it one eye at a time and relating it to our background, we can determine how close it is to our face because of how dramatically different each side sees it “change” distance. The further away from our face we place our finger, the smaller the parallax, until it is so far away that it just blends in with the background (maybe if we had detachable fingers, but I digress). Similarly, scientists determine the distance a star is from Earth. A “close” star is observed in relation to the “fixed” stars in the background and the two are compared when the Earth on opposite sides of its orbit. This way scientists see the two extremes of the star’s parallax motion in the night sky. They then use geometry to come up with the parallax angle.

Image result for parallax angle

Knowing this parallax angle, scientists use some more geometry to figure out the distance to the star. This distance is is described in the unit of length called the parsec. One parsec is the distance to a star that has a parallax angle of 1 arcsecond. Also, parsecs and parallax angles are reciprocally related; The smaller the parallax angle, the larger the distance to the star. For example, if a star has a parallax angle of 1/6 of an arcsecond, the distance to that star is 6 parsecs. However, no star is actually that close, so the act of figuring out the distance is a little harder on an even smaller-angle and larger-distance scale. In relation to distance, these two stars in Gemini are actually relatively close, one being at 50 light years and the other at 34.  Since these stars are so “close”, it can be assumed that the parallax they display every 6 months is greater than other constellations that are farther away.

When it came to measuring the size and mass of other stars, scientists use distance in conjunction with its luminosity to determine those traits. When comparing two equidistant to us but near each other stars and comparing their luminosities, the larger star will appear to be more luminous, therefore knowing the distance and luminosity to a star can determine its size. A more massive star will appear to be more luminous at a distance as well. Relating to the article, while both Pollux and Castor seem to be about the same apparent luminosity, Pollux is about 16 light years closer than Castor, meaning that its actual luminosity is much dimmer than that of Castor.

Upon constant reflection on how stars are are studied and characterized, I feel as though I am more comfortable with sharing my knowledge with others. Besides being a thoroughly useful topic in understanding the world beyond us, astronomy is a field in which many take interest into but do not know where to start in gaining understanding. Attending these lectures and taking this class encourages me to inspire others to pursue an education in the sky, even if it is just for fun.