APOD 3.2

This is an image of the Polar Ring Galaxy NG660. I chose to write about it because it is such a strange type of galaxy. Its massive ring system orbits it almost perpendicular to the spiral, which is a very unpredicted place for it to be. The fact that an entire galaxy can have a ring system is simple amazing, the amount of debris that must be collected for it to occur is gargantuan. The ring system spans about 40,000 light years and there is very few things that could have caused this system to form. One of the most likely hypothesis for this is that another galaxy with a tail of debris passed closely by it and this galaxy captured the tail and formed these rings. Whatever happened to form this ring was truly amazing, this image shows how many possibilities of galaxies are available in the universe and no matter how minuscule the chance of one of the occurring is, it will happen somewhere in the universe.

APOD 3.1

Today I chose to write about Alnitak, Alnilam, and Mintaka because of how unique they are in the night sky. They are the only 3 2nd magnitude stars in the night sky that line up to form an almost perfectly straight line. These stars look astounding in this picture as they are a very bright blue and dwarf our own Sun in comparison to its size. There are also several other unique astronomical sights that are in this picture, such as the Horsehead Nebula and the Flame Nebula. All of these things combine to create a beautiful picture. This is the major reason that this area of the sky is so interesting to look at, there are over 7 bright stars in a very small area along with nebulae and other objects that are fascinating to study.

Fission Astronomy Cast

Fission is essentially the opposite of fusion, in which heavy unstable atoms decay either rapidly or over long periods of time. Carbon 14 is one of the most commonly known isotopes that undergoes fission. It has a half life of about 5,700 years, meaning that it decays to half of its original mass in 5,700 years. The other common kind of process is the rapid process. This process is most widely recognized in bombs. When very heavy, unstable elements rapidly undergo fission they release massive amounts of energy. However, the slow process is the more common form of this as it requires more stable elements, which are more common in nature. Another interesting fact about this process is the idea of a chain reaction. Each time an element undergoes fission it releases neutrons. These neutrons then go on to induce other elements to fission, which then release more neutrons. When there is a certain amount of mass the process becomes self propagating and it is said to have reached critical mass. Fission can also be used to determine the age of stars by determining the half life of a certain element is and figuring out what percentage of it remains. Overall, fission is very important in the universe and has many practical purposes on Earth as well.

Fusion Podcast

This podcast is about nuclear fusion, largely in the center of stars. The core of many stars are extremely hot, over 10,000,000 degrees Kelvin. When the temperature is this high, the particles in the sun, such as hydrogen atoms and electrons, move at extremely high velocities. At these velocities it is possible for the atoms to overcome the repulsive forces of their charges. If 2 hydrogen atoms collide at a high enough velocity they will fuse together and create heavy hydrogen, which is a hydrogen atom with a neutron. This reaction also produces energy on the level of 1-10 MeV along with neutrinos. This heavy hydrogen then collides with another proton and then with another proton to create a helium atom. These reactions release photons with a blackbody spectrum that peaks in the ultraviolet range but also releases photons up to the gamma ray section. If the Sun could be seen outside the Earth's atmosphere it would appear to be a whitish color because it releases all the visible colors, which forms white. The process of fusion also is what keeps the star 'inflated.' Without this energy pushing the outer layers out, then gravity would cause the star to collapse in on itself and possible create a supernova. Nuclear fusion can be used on Earth to create energy, but the problem is that storing the fusion takes more energy than the fusion itself creates, so there is no point to do it. Solving this problem could greatly reduce the energy crisis on Earth and could be used for great benefit to mankind.

Sun Pictures

http://www.lookpictures.net/gallery/Space/1792/Sun-Extreme-Ultraviolet-Imaging-Telescope-Wallpaper/
http://apod.nasa.gov/apod/ap980923.html
http://apod.nasa.gov/apod/image/0702/cmesun_soho_big.jpg
http://spacefellowship.com/news/art21900/map-of-magnetic-field-lines-of-the-sun.html
http://astronomy.neatherd.org/Swedish%20sunspots1.jpg
http://umbra.nascom.nasa.gov/eclipse/images/freds_excellent_eclipse_img.jpg
http://apod.nasa.gov/apod/image/0604/eclipse2006_seip_big.jpg

Friedrich Georg Struve

Andrew Sanderson
Period 3
Due 11 January 2011

Friedrich Georg Struve

Friedrich Georg Struve was born in Germany on April 15th 1793 into a fairly wealthy and well educated family. When he reached the age of conscription he was sent away to live with his brother in Russia. He graduated from the Russian University Dorpat in 1810 with a degree in philology. However, he did not want to pursue a career in this subject, so instead he began to study mathematics, astronomy, and geodesy. He got his doctorate for accurately determining the location of his university’s observatory and then began to teach. He taught for 25 years in which he lectured in math and astronomy. Astronomically, Struve is famous for many things, most notably in his research and observation of double stars, the observation and determination of stellar parallaxes, the distribution of stars in space, the observation of planets, the moon, comets, and auroras. He also created new and better instruments and refined the old ones to get more accurate and reliable measurements and data. One example of these new instruments he created was when he added a meridian circle and a nine-inch refracting telescope, which was the largest at that time, to the observatory. After this he then moved to a newer observatory in St. Petersburg. He was appointed to the position of director of installation and was tasked with getting the best instruments he possibly could. Among the several new instruments he ordered was a 15 inch refracting telescope, which was now the largest one ever made. After this time he observed about 122,000 stars from the North Pole to 15 degrees south declination. Among these stars he discovered 3,112 double stars, which had previously been undetected. He then began to make micro metric measurements of these stars and tried to determine their angular separations and parallaxes. However, because of the age in which he did this and the limits of his instruments, he was unable to determine very many of the parallaxes accurately, as many of them were less than .5”. With respect to the research he did about the distribution of stars, he wanted to determine if there was a statistical dependence between the brightness of stars and their distance. Among the many conclusions of this research, he was able to conclude that the Sun doesn’t lie at the center of our galaxy, but is rather above its plain. Struve also postulated that light traveling through the Universe is absorbed, so that distant stars cannot be seen because the light from them isn’t bright enough to reach Earth, and the value he came up with is still in use today. Struve also did a lot of research in the field of geodesy. He came up with rational methods to figure out the time, latitude, and azimuth of celestial objects. By doing this he was able to eliminate systematic error that plagued the old methods. At the end of his life he was a member of over 40 scientific academies and universities and founded the Russian Geographical Society. He died on November 23, 1864 and was survived by his wife and 12 children, some of whom went on to do notable astronomical research.

APOD 2.8

Today I chose to write about the lunar eclipse on Earth taken by the Mir Satellite. This image is so amazing to look at because it shows how large of an effect the lunar eclipse has on the Earth and it is shocking to see it from this vantage point. The fact that this shadow moved across the Earth at 2000 kilometers an hour is also stunning because when one puts this in perspective to the average speed of a car or airplane it becomes enormously fast, especially considering the mass and volume of the object that causes it.

APOD 2.7

I chose to write about M82 this week because it is one of the strangest looking galaxies that I have seen. Most galaxies that I have seen pictures of have been spiral galaxies, but this one looks like a bow tie with a cigar going through the middle of it. I really would like to know how a galaxy forms in this unique shape. Along with the shape of it, the sheer dimensions amaze me. The filaments themselves extend over 10,000 light years. This number is completely incomprehensible and is simply stunning to think about, which is another reason why I chose to write about M82 this week.

Friedrich Georg Struve Biography Sources

Complete Dictionary of Scientific Biography. Vol. 13. Detroit: Charles Scribner's Sons, 2008. p108-113.

"Struve, Friedrich Georg Wilhelm Von (1793-1864)." The Worlds of David Darling. Web. 05 Jan. 2011. .