Hertzsprung-Russell Diagram

I recently read an article that is titled, “Astronomers discover a white dwarf that acts like a pulsa”. I believe that this specific article directly correlates with our twelfth conceptual “I can explain how astronomers use the Hertzsprung-Russell diagram to study properties of stars“. This article begins by introducing that many astronomers are incredibly fascinated by pulsars because of their unique and exotic features. A pulsar is a type of neutron star that emits focused beams of radiation from its poles as it spins. But now, astronomers have discovered a pulsar that’s not a neutron star at all, but a white dwarf. After more than fifty years of intense searching of something in comparison to this object, the first white dwarf star was discovered. The two Professors that discovered this incredible phenomenon found out that the binary system AR Scorpii (AR Sco) contains a white dwarf acting as a pulsar. This also is located at about 380 light-years away in the constellation Scorpius. Inside the Ar Sco is a white dwarf and a red dwarf star. Both of these stars orbit each other about every 3.6 hours. The distance they do this is 1.4 million kilometers. This is three times the distance between our planet Earth and the moon! Therefore every two minutes when the white dwarf rotates around its axis, it blasts its’ companion with a beam of radiation that gets the electrons going into the red dwarf’s atmosphere. The particles are accelerated directly to the speed of light. This explains the why there is brightness change that can be seen from the naked our from planet Earth at exactly the same time of the white dwarf’s rotation.eso1627a.jpg

I really enjoyed this specific article because it truly gives a great representation of our twelfth conceptual objective. During our class lecture, we took descriptive notes that explained what the Hertzsprung-Russell diagram is and what is also included in it. We learned that the majority of the stars are classified in the Main Sequence, Next there are Giants, which are brighter and larger than most would think. This is not in the Main Sequence. In addition, there also is white dwarfs that are often cool and dim; while red dwarfs are warm and bright. On page 117 in our lecture-tutorial book, we practiced to learn the conceptual objective. I believe that this article was a perfect representation of our twelfth objective because it throughly went through all the material that we learned in class. I find it so interesting our much our Sun can be lower in size compared to some of the other stars in our solar system. Overall, I confidently believe that I thoroughly understand our twelfth conceptual objective, “I can explain how astronomers use the Hertzsprung-Russell diagram to study properties of stars”.

 

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Singing: We Are a Family, We’ve Got a Lot of Ga-lax-ies

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(Hubble Space Telescope image of the galaxy cluster Abell 370)Credit: NASA, ESA, and J. Lotz and the HFF Team (STScI)

What appropriate words from Sister Sledge (with a little bit of me added in)!  Well, isn’t that what the universe is?  One big families with numerous galaxies, right?

In a recent article I read on Space.com entitled, Paging Star-Lord! Hubble Spies Hundreds of Galaxies That Need Guarding, author Hanneke Weitering talks about some new shots of several galaxies taken by the Hubble Space Telescope.  One galaxy cluster located in the images in particular was Abell 370.  The galaxies within this cluster were pretty faint so the observers used gravitational lensing to help view the celestial bodies.

Although the clusters and specific galaxies are a little fuzzy, from the picture you can still see some of the coloring present within the arms of the different types of galaxies.  As we learned in class, the Milky Way is a barred spiral galaxy.  The outer portion of barred spiral galaxies and spiral galaxies tend to have more blue coloring around the arms or edges of the galaxies.  This is a sign of hot, bright, luminous stars being formed or forming recently like the slide presentation from class shown below.

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In the picture at the top of the page, it is very clear (although tiny) that there are several galaxies that exhibit the same galaxy structure as our Milky Way by just observing the color and structure of the galaxies shown.

In a lecture tutorial we worked on in class entitled, Galaxy Classification (a portion pictured below), we reviewed the different shapes of galaxies represented within our solar system and how their coloring tells us a lot about the activity that may or may not be going on currently and what may have transpired in the past.

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Truthfully, we are a family of galaxies.  This article confirmed just a portion of that just by reading it and seeing the similarities among galaxies in the pictures.  What I find the most interesting is not just all the similarities among the galaxies pictured and that of our galaxy, but I find that gravitational lensing reminds me of the view one gets when the flash on their phone leaves a fuzzy remainder when taking pictures.  In a way, the similarities will help me to recognize the use of gravitational lensing in the future.

 

How We Know the Universe Is Expanding, and Accelerating

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In the article, “How We Know the Universe is Expanding, and Accelerating,” the author talks about how our universe is expanding. “Everything in the universe is slowly moving farther away from everything else. Even the molecules in your body are drifting away from one another”.  The author states, that this expansion of the universe was first discovered by Edwin Hubble in 1931. Hubble made this discovery by studying the Doppler effect. The author explains how this helped make the discovery because “The same thing happens with light waves. When a galaxy is moving away, the color of the light shifts toward the red end of the spectrum.” . Next, after Hubble observed the redshifting in every galaxy he came to the conclusion that the entire universe is expanding. However , it is observed by Hubble that the galaxies that are farther apart are expanding faster then the galaxies that are closer together. Next, the author states, “in 1998, another Hubble—the Hubble Space Telescope—made another startling discovery about the universe’s expansion.” This telescope helped astronomers discover that the universe is not only expanding , it is also accelerating. Lastly, astronomers have not yet came to a complete conclusion on why the universe is accelerating , but they do know there is some kind of energy pushing it apart.

Objective 17 was to be able to explain how astronomers know that the universe is expanding and how they determine the age of the universe. The article explains how Hubble discovered that every galaxy seems to be moving away from the earth. This directly corresponds to what we did in class on the screen with the different dots. During this activity , someone would choose a dot and say it was our Milky Way galaxy and then when we would put a blown up image of the dots over the top of it and it would show all of the other dots “running” away from the central dot. Also, just like the article the farther the dot , the more it seemed to be moving away. Just like the article explains about the galaxies; every galaxy astronomers have observed seem to be moving away, and the father the galaxy the faster it is moving away. Astronomers believe dark energy is what is causing the universe to expand and accelerate. In the textbook, most of a galaxy’s mass is in the form of dark matter and the gravity of that dark matter is probably what formed protogalactic clouds and galaxies from slight density enhancements. Therefore, the evidence points to eternal expansion given that the overall matter density of the universe appears to be only about 25% of the critical density. Lastly, as a further classmate pointed out to me, The Big Bang can also show the universe is expanding. It shows this by looking back there was nothing but radiation and elementary particles. The further into the future you go, the bigger the universe has become.  The universe is now 1,000 times larger now.

I found this article personally pretty interesting. The reason I say this is because I learned something knew about our universe. However,  learning that the universe is expanding and accelerating is not what interested me. The actually interesting part to me is how this article got me thinking in the future how this expanding and accelerating will affect me personally along with earth and the people in it as a whole.

Nature of Our Solar System

The article that I recently read was titled, “Mars is so small because Jupiter shook up its formation“. This specific article directly ties into our tenth conceptual objective, “I can describe the nature of our solar system and how it was formed”. This article begins by a very blunt way of what astronomers believe is the reason for Mars’ size. Abigaill Beall simply states, “Mars can blame Jupiter for its small stature. The Red Planet may be much smaller than we expect because Jupiter’s gravity beat it up as it was forming”. Many experts say that Mars’ mass is supposed to be 1.5 and 2X Earth’s mass. Instead, it weighs in at a shy one-tenth mass of our world. A theory that was once said is suddenly resurfacing. Some say that after the formation of Jupiter, gas that was left over meddled with the rocks that ultimately built Mars. Therefore, instead of them clumping together, they seemed to fall apart. The gas giants formed by accreting gas from the protoplanetary disc that surrounded the sun. As they increased in size, their gravity started to have more impact than the remaining disc on the still-forming rocky planets. I think this was a great article to correlate with our objective. When the gravitational pull collided between the two, the protoplanets felt a kick from Jupiter’s Gravity at the same point in their orbit around the sun, an effect known as sweeping resonance. In our lecture, we discussed that scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion made waves in space which squeezed the cloud of gas and dust. Many meteorites even discovered that Mars grew much more rapidly than assumed. Therefore, the consequences for a disk that resolves more rapidly was discussed

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I felt like this article was a great representation of our conceptual objective we had to elaborate on. Before discussing this topic in class and reading this article, I did not know the outside forces can alter a planet’s size forever. In addition, we learned in our lecture-tutorial handbooks that there are two type of planets.First is the Jovian planets (gas planets) which formed at temperatures cooler than the freezing point of water. Next, is the terrestrial planets (rocky planet) which formed hotter than the boiling point of water. Just by knowing that planet Earth was ultimately formed as a spinning cloud of dust, certainly blows my mind. You just think of how evolved our planet is and what it withholds, and find it crazy how just a simple natural act created it. I strongly believe this article helped me immensely understanding our tenth objective, “I can describe the nature of our solar system and how it was formed”.

Formation of the universe

4.5 billion years ago our solar system was formed. Many wonder how it was formed. Space.com has an article called “How did the Solar System form?” and it explains how the solar system was formed and all the different models scientists have come up with to determine what happened. First the Sun was born from a massive dust and gas cloud, while gravity grew denser, gas clumped together. The gas became so dense that it formed a star, our sun, and had a ring around it of material that would turn into the planets. The planets would not form until another 100 million years. In the core accretion model, The solar wind swept away lighter elements, such as hydrogen and helium, from the closer regions, leaving only heavy, rocky materials to create terrestrial worlds. But farther away, the solar winds had less impact on lighter elements, allowing them to coalesce into gas giants. In the disk instability model, clumps of dust and gas are bound together early in the life of the solar system. These clumps slowly pack into gas planets, reach a stable orbit mass and form quicker than in the core accretion model. The pebble accretion model says that pebble-sized objects fused together to build giant planets up to 1,000 times faster than earlier studies.

In the lecture tutorial on page 111, there is a graph showing the temperature and distance from the sun by which each planet was formed. Terrestrial planets such as Mercury, Venus, Earth, and Mars were formed at much higher temperatures then gas giant Jovian planets like Jupiter, Saturn, Uranus, and Neptune. This article correlates to our conceptual objective 10 I can describe the nature of our solar system and how it was formed because it talks about how the sun was formed and how the planets around the sun started to form.

I enjoyed reading this article because it helped me understand more on how our solar system was formed. It was very informative and explained everything throughly.

Tele(scope) it Out!

I recently read an article that was titled, “Hubble Space Telescope: Pictures,Facts, and History“. This specific article ties into our ninth objective, “I can describe: 1.) the functions of a telescope, 2.) types of telescopes and 3.) why some telescopes are placed on the ground and some in space”.  For the introduction, the author Nola Taylor Redd, begins by explaining the overall history of the Hubble Space Telescope. Since its’ initial launch in 1990, there have many different advancements and discoveries from the Hubble Space Telescope. Since the technology has improved, the telescope allows astronomers to get a first hands view of planets, stars, and even distant galaxies. We discussed in class how Earth’s atmosphere effects immensely on our optic view of other astronomical objects, even using the Hubble Space Telescope. We also learned how the atmosphere absorbs radiation, except at visible light, infrared, and radio frequencies, which is why the most important reason behind having telescopes in space is so astronomers can observe light that does not penetrate Earth’s atmosphere. Although we have telescopes in space that can relay us a more vivid picture, the article explains that the telescopes on ground are much less expensive. But with the new technology the space team is able to obtain, the images from ground are able to overcome any atmospheric distortions. However, the article states that when the telescope was launched and ready to use, there was a flaw. The mirror had issues and all of the pictures came out extremely fuzzy and useless.  This ties back into our objective when discussing how telescopes function. There are two types of telescopes; refracting and reflecting. A refracting telescope is a type of optical telescope that uses a lens as its objective to form an image. An optical telescope which uses a single or combination of curved mirrors that reflect light and form an image is a reflecting telescope. Although both of these telescopes have these differences, they both are an amazing way to capture the optic view of astronomical objects,

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I really enjoyed this article because it was able to connect all points of the objective, in a very informational article. I was also able to learn about the Hubble Space Telescope, all while connecting it to our objective we discussed in class. In addition, I remembered some of the aspects of the refracting and reflecting telescope from previous science classes. Therefore, I was able to absorb new information learning from our current objective, all while knowing the information I knew before. All in all, I believe I am confident in this objective.

How Fast is the Universe Expanding?

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The seventeenth conceptual objective, “I can explain how astronomers know that the universe is expanding and how they determine the age of the universe”, has been a topic discussion in class as of late. Hubble’s Law is a powerful tool that tells us that the universe is expanding. Hubble’s discovery indicated that galaxies are moving away from us. The universe is not expanding into anything. Essentially, it is never ending. The expansion of the universe can be compared to an inflating balloon. We exercised this concept in class using the projector. Several dots were drawn on a piece of paper, then blown up in size. When one dot was picked, the larger image was placed directly on top. However, it suggested that the dots were moving away from each other, much like galaxies in our universe. Ultimately, the spaces in between the galaxies are increasing. Therefore, this suggests that our universe is expanding. The universe is said to be about 14 billion years old. But how do astronomers know this? The speeds and distances to other galaxies, and the rate at which the universe is accelerating, allows astronomers to estimate the age of the universe. Astronomers can also look at some of the oldest stars to determine the age. Ultimately, the rate at which the universe is expanding suggests how old it is. In the section titled, “Expansion of the Universe”, in the Lecture-Tutorial book, we were asked to examine the distances between various galaxies. This allowed us to describe how the universe is changing. This tutorial has given me a better understanding of how the universe is changing and how the rate it is expanding determines its age.

The article I chose, “We Still Don’t Know How Fast the Universe is Expanding”, focuses on determining the rate at which the universe is expanding. Scientists still do not know how fast it is expanding. This article suggests that astronomers are still trying to determine the exact speed. It discusses how astronomers are continuing to determine the rate and how they do so. This article talks about how Edwin Hubble noted that the farther away a galaxy was, the faster it was moving away from us. This is known as Hubble’s Law. The main goal of the Hubble Space Telescope was to determine the rate at which the universe was expanding. Still to this day, scientist cannot come up with an agreement. The rate that the universe is expanding at is still somewhat of a mystery. The closer we get to determining the exact rate, the better understanding we get of the age of the universe. This article clearly demonstrates how astronomers are still, to this day, studying the age and expansion rate of the universe.

This article compares to the seventeenth conceptual objective because it explains how the universe is expanding. By understanding this rate, astronomers are able to determine the age of the universe. Over the years, many scientists have given their estimates about how fast the universe is expanding. The closest we have gotten was the measurements recorded by the Hubble Space Telescope. This article does a great job in explaining how far we have come in determining the rate at which the universe expands. The estimated age of the universe will become more accurate as the time goes by. This article was very interested to me, as it allowed me to get a better understanding of how astronomers know the age of the universe.