APOD 4.7

This weeks picture is of Saturn's moon Rhea, which has one of the oldest surfaces known. Rhea spans 1,500 kilometers making it Saturn's second largest moon after Titan. Estimated as changing little in the past billion years, Astronomers believe Rhea has remained unchanged in a billion years! Rhea contains craters that are so old they are no longer round and have jagged edges. Rhea's rotation is locked on Saturn like our own moon and the picture shows the side of Rhea that is constantly facing Saturn. Rhea is made up of mostly water-ice (whatever that is)but it is believed to be made of 25 percent rock and metal. The robot Cassini took this picture last month from 350,000 kilometers away! It's amazing that a quality image like the one above can be taken at such a far distance.

Biography: Subramaniam Chandrashekhar

Subrah Chandrasekhar, known to the world as Chandra was born on October 19, 1910 in Lahore, India. Subrah was nephew to Nobel-prize winning physicist C.V. Raman. He received most of his school education by private tuiton and graduated from Presidency College Chennai in 1930 with a degree in physics. In July after he graduated, Chandrasekhar was awarded a Government of India scholarship to pursue graduate studies at the University of Cambridge, where he was admitted to Trinity College and became a research student of Professor R. H. Fowler. On the way to England Chandrasekhar discovered his biggest astronomical success the astrophysical Chandrasekhar limit. The limit describes the maximum mass of a white dwarf star, or the minimum mass above which a star will ultimately collapse into a neutron star or black hole. When Chandra first proposed this limit during his fellowship at Trinity college in the 1930's, it was obstinately opposed by Arthur Eddington and much to Chandra's frustration none of the established physicists in Europe came to his rescue. This episode had a bitter impact on Chandra resulting in his move to the University of Chicago in the United States and in his choice of moving to another research topic. Chandra, however, compiled all his work on the topic of stellar structures into a book for posterity. This also subsequently led to his style of working continuously in one specific area of physics for a number of years and at the end of that period compiling a book on that topic. As a result, Chandra has left us with great expositions on different topics. Chandrasekhar developed a style of working continuously in one specific area of physics for a number of years; consequently, his working life can be divided into distinct periods. He studied stellar structure, including the theory of white dwarfs, during the years 1929 to 1939, and subsequently focused on stellar dynamics from 1939 to 1943. Next, he concentrated on the theory of radiative transfer and the quantum theory of the negative ion of hydrogen from 1943 to 1950. This was followed by sustained work on hydrodynamic and hydromagnetic stability from 1950 to 1961. In the 1960s, he studied the equilibrium and the stability of ellipsoidal figures of equilibrium, but also general relativity. During the period, 1971 to 1983 he studied the mathematical theory of black holes, and, finally, during the late 80s, he worked on the theory of colliding gravitational waves. Subrahmanyan Chandrasekhar tragically died of heart failure in Chicago in 1995. In 1999, NASA named the third of its four "Great Observatories'" after Chandrasekhar. The Chandrasekhar number, an important dimensionless number of magnetohydrodynamics, is named after him, as well as the asteroid 1958 Chandra.
Works Cited
Wali, Kameshwar C. (1991). Chandra: A Biography of S. Chandrasekhar. Chicago: The University of Chicago Press.
Wali, Kameshwar C. (ed.) (1997). Chandrasekhar: The Man Behind the Legend - Chandra Remembered. London: imperial College Press.
"The Man Behind the Name." Subrahmanyan Chandrasekhar. 29 Aug. 2006. Harvard U. 8 May 2008 .

APOD 4.6

This weeks photo was taken in Chile last October and shows a faint glow which is the gegenschein. Gegenschein is a faint brightening of the night sky in the region of the ecliptic directly opposite the Sun. The gegenschein is so faint that it cannot be seen if there is any moonlight or light pollution, or if it falls in the vicinity of the Milky Way. The orientation of the ecliptic at this time of year makes it a favorable time for trying to view optical phenomena associated with dust in the plane of the planets. The zodiacal light and the gegenschein which is German for counter-glow, often easily viewed in the tropics, are seen in the morning sky for our latitude in September and October. Also visible in the background is the Andromeda galaxy in the lower left as well as the Pleiades. During the day, a phenomenon similar to the gegenschein called the glory can be seen in reflecting air or clouds opposite the Sun from an airplane.

APOD 4.5

This is a photo of specifically Messier 86 which is one of the brightest galaxies of the Virgo Cluster Galaxies, and is situated close to the cluster's center. With well over a thousand members, the Virgo Cluster is the closest large cluster of galaxies. On average the cluster galaxies are measured to be about 50 million light-years away. M86 was discovered and cataloged by Charles Messier on March 18, 1781 when he also cataloged 7 more nebulous objects in the same region of the sky. This bright giant galaxy is either an elliptical of type E3 or a lenticular galaxy of type S01. M86 is the galaxy which has the fastest approaching velocity, and thus the highest blue shift, of all Messier galaxies.

APOD 3.4

Stickney crater is the largest crater on Phobos, which is a satellite of Mars. It is located at 5°S 55°W on Phobos and is 9 km in diameter, taking up a substantial proportion of the moon's surface. It is named after Chloe Angeline Stickney Hall, wife of Phobos's discoverer, Asaph Hall. It has a smaller, unnamed crater within it, resulting from a later impact. Grooves and crater chains appear to radiate from Stickney, and had led to theories that the impact that formed it nearly destroyed the moon. It is possible that Stickney is large enough to be seen with the naked eye from the surface of Mars. It is located at the middle of the left edge of Phobos's face, on the Mars-facing side. This incredible picture of Stickney was taken by the Mars Reconnaissance Orbiter as it passed within six thousand kilometers of Phobos last month.

APOD 4.3

This week's astronomy picture is of Jules Verne European Space Agency's Automated Transfer Vehicle. It was used for the first time on April 25th to raise the orbit of the International Space Station. A 740-second burn of the Automated Transfer Vehicle's main engines successfully lifted the altitude of the 280 ton station by around 4.5 km to a height of 342 km above the Earth's surface. The ATV was named after Jules a French author who pioneered the science-fiction genre. He is best known for his novels Journey to the Center of the Earth, Twenty Thousand Leagues under the Sea, and Around the World in Eighty Days. Verne wrote about space, air, and underwater travel before navigable aircraft and practical submarines were invented, and before any means of space travel had been devised. Using a laser guided rendezvous system, the Jules Verne docked smoothly and safely with the orbiting station on Thursday, delivering 7,500 pounds of equipment, supplies, and fuel.

APOD 4.2

This weeks APOD is titled Across the Universe (aka best movie ever!) and is a picture of a cosmic explosion classified as GRB080319B and detected by the Swift satellite. The source of the flash is estimated to be over 7.5 billion light years away, an unfathomable distance, and is 2.5 million times more luminous than the brightest supernova we know of. Obviously this is incredibly important discovery, and by observing the optical emission during the gamma ray burst, which usually last less than 2 minutes, we c an begin to understand the mechanism releasing enormous amount of energy. It is commonly believed that in the case of GRB longer than 2 s the phenomenon is caused by a collape of a massive star ending with a formation of a black hole. However, the details of the process still remain uncertain.

APOD 4.1

This weeks APOD is a reprocessed picture of the Cat's Eye Nebula taken by the Hubble Space Craft. It is a planetary nebula in the constellation of Draco. Structurally, it is one of the most complex nebulae known, with observations made by the Hubble Space Telescope revealing remarkable structures such as knots, jets and sinewy arc-like features. It is a sun like planet and scientiists believe our sun to follow the same phases in about 5 billion years. It was discovered by William Herschel on February 15, 1786, and was the first planetary nebula whose spectrum was investigated by the English amateur astronomer William Huggins in 1864. The intricacy of the structure may be caused in part by material ejected from a binary central star, but as yet, there is no direct evidence that the central star has a companion. The remake image focuses on sharpening the visiblility of details in light and dark areas of the nebula.

Observation 3.2

Date: March 7, 2008
Time: 8:45-10:40
Place: Near the Sarasota square mall
Sky conditions: Pretty clear, only a few clouds

Bright Stars: Betelgeuse, Rigel, Sirius, Castor, Pollux, Capella

Constellations: Orion, Ursa Major, Gemini, Auriga

Planets: Saturn was a yellowish looking star in Leo and Mars was an orangish color and looked like a star above the constellation Orion.

Other: The Big Dipper was visible in Ursa Major. The moon however was no visible. Orion's Belt was also easily spotted in the constellation of Orion.

Planatary Nebula

APOD 3.9

This weeks picture is of defrosting sand dunes. By observing the changing patterns in sand dunes, scientists can learn about the interaction between the Martian surface and the atmosphere. Dune activity can help them understand the rate at which the Martian wind moves sediments around, as well as to estimate how long it takes for windblown sand to abrade the surfaces of rocks; not to mention our Mars landers. Dunes were first detected by the Mariner 9 spacecraft in the early 1970s, and are actively studied by the Mars Global Surveyor orbiter today.These ripples, like small sand dunes, are common on Mars and are usually found in low-lying areas and inside craters. They can be up to 20 feet tall and form really crazy and dramatic patterns. SWEET!

Observation 3.1

Feb. 20
Near the Mall
Lunar Eclipse
Binoculars used for about 30 minutes total
Even though it started to rain the weather didn't affect the view of the third total lunar eclipse this year. This was the last lunar eclipse until December 2010.Before going out to view this spectacle I decided to research it a bit to see if there were any items I needed to see it or any particular details that would make it more interesting. I found out that almost 3 billion people were able to view the eclipse as well. So I went outside with my binoculars and watched as the moon was gobbled up by darkness. I started to watch at around 9 at night the process lasted till a little bit before 11. When I started to watch there was only a partial eclipse but by about 10 it had turned into a total eclipse. This was really cool because many of the stars in the sky that were washed out before were now visible and bright. The eclipse appeared a reddish orange color. If the Earth had no atmosphere, then the Moon would be completely black during a total eclipse. Instead, the Moon can take on a range of colors from dark brown and red to bright orange and yellow.

Observed Magnitude of Stars

Eta Aurigae: 3.5
Beta Eridani: 4.2
Gamma Orionis: 2.1
Beta Tauri: 3.2
Delta Orionis: 1.5
Zeta Orionis: 1.9
Mu Geminorum: 3.0
Xi Geminorum: 3.8
Sigma Canis Majorum: 4.2
Eta Canis Majorum: 2.5
Alpha Geminorum: 1.3

Edward E Barnard Biography

Edward Emerson Barnard was an American astronomer. He is best known for his discovery of Barnard's star in 1916, which is named in his honor. He was born in Nashville, Tennessee, to Reuben Barnard and Elizabeth Jane Barnard, and had one brother. His father died before his birth, so he grew up in an impoverished family and did not receive much formal education. He later developed an interest in astronomy, and in 1876 he purchased a 5-inch refractor telescope. In 1881 he discovered his first comet, however he failed to announce his discovery. He found his second comet later the same year and a third in 1882. During the 1880s, a wealthy patron of astronomy in Rochester, New York, awarded $200 each time a new comet was found so that Barnard soon earned enough to build a “comet house” for his bride. His discoveries and brilliance as an observer drew the attention of other amateur astronomers in Nashville who raised enough money for Barnard to attend Vanderbilt University.
In 1892 he made observations of a nova and was the first to notice the gaseous emissions, proposing that it was a stellar explosion. The same year he also discovered Amalthea, the fifth moon of Jupiter. He was the first to discover a new moon of Jupiter since Galileo Galilei in 1609. This was the last satellite discovered by visual observation. In 1895 he joined the University of Chicago as professor of astronomy. There he was able to use the 40-inch telescope at Yerkes Observatory. On May 29, 1897, Barnard narrowly escaped death when, just hours after he had left the observatory’s dome, the 37-ton elevating floor, used to lift observers to the level of the telescope’s eyepiece, collapsed after a supporting cable broke. Much of his work during this period was taking photographs of the Milky Way. Together with Max Wolf, he discovered that certain dark regions of the galaxy were actually clouds of gas and dust that obscured the more distant stars in the background. Edward Barnard discovered Barnard's Star in 1916 and that it had a very large proper motion, relative to other stars. This is the second nearest star system to the Sun, second only to the Alpha Centauri system. He was also a pioneering astrophotographer. He died on February 6, 1923 in Williams Bay, Wisconsin, and was buried in Nashville. After his death, his exceptional collection of photographs was published as Photographic Atlas of Selected Regions of the Milky Way. Barnard was awarded the Gold Medal of the Royal Astronomical Society in 1897, and then in 1917 was awarded the Bruce Medal. His life's work included nearly four thousand photographs and 840 separate addresses and articles. He is thought of as one of the greatest observational astronomers of his time.

Works Cited

Kenneth Glyn Jones. Messier's Nebulae and Star Clusters. Cambridge University Press, 1991.
Tenn, Joe. "Edward Emerson Barnard". The Bruce Medalists. March 10 2006. March 4 2008.

APOD 3.8

This weeks apod is of the LDC, Large Hadron Collider (LHC), built in Europe by CERN, the European Organiztion for Nuclear Research, is the wordl's largest particle accelerator. The image is particularily of the ATLAS detector, one of the six detectors being attached to the LHC. A prticle accelerator is a device that uses electric fields to propel electrically-charged particles to high speeds and to contain them.They come in two basic types which are linear accelerators and circular accelerators. An ordinary television set is a simple form of accelerator. The LHC is schedule to start performing in May of this year. The LHC will hopefully be responsible for exploring the explanation that mass arises from ordinary particles that "slog" through Higgs particles. LHC will also look for micro black holes, magnetic monopoles, and explore the possibility that every type of fundamental particle we know about has a nearly invisible supersymmetric counterpart. How exciting!

APOD 3.7

This weeks picture is of the crab nebula taken by the hubble space telescope. The crab nebula is about 10 light years wide and rotates almost 30 times every second. It is the remains of a supernova that was apparently seen(not really sure by who) in 1045 AD. The filaments in this explosion are unknown and complex and appear to have less mass than expelled in the original supernova. No radio emission was detected from an extended source outside the Crab Nebula. Scientist say that its pretty safe to say that there is no shell in exsistance aound the nebula and the brightness of the crab is at the very least 2 magnitudes below the faintest shell-type supernova known. Another interesting fact about the nebula is that at the center or relatively close to the center that is, is a pulsar which is a netron star that has as much mass as the sun but is actually only the size of a small town.

Edward E. Barnard Biography Sources

Hardie, Robert H., Dictionary of Scientific Biography 1, 463-67.
http://www.phys-astro.sonoma.edu/BruceMedalists/Barnard/index.html

APOD 3.6

This photo is of the cluster Abell 2218. The bright objects are galaxies in the cluster that are distorted into long faint arcs by a simple lensing effect that is almost like viewing street lights through a glass. Because there are so many galaxies in the cluster and it is so massive and compact, gravity bends and focuses the light from the galaxies lying behind it. A gravitational lens is formed when the light from a very distant, bright source is bent around a massive object between the source object and the observer. The cluster Abell 2218 is about three billion light years away, relatively close (NOT!), and located in the northern constellations of Draco. The power of this massive cluster telescope has lead astronomers to detect the most distant galaxy ever measured.

Apod 3.5

NGC 4013, located in the constellation Ursa Minor nearly 50 million light-years away was considered to be an isolated island universe. This galaxy is known for its flattened disk and central bulge of stars. However this weeks image of the galaxy shows a faint looping structure never seen before. It seems to extend about 80 thousand light-years from the center of the galaxy, and is discovered to be a bunch of stars that originally were apart of another galaxy. This phenomenon was liekly due to a smaller galaxy being torn apart by gravitational tides and then merging with a larger galaxy. Some astronomers argue that this recently discovered tidal stream offers parallels to how our own Milky Way Galaxy formed.

APOD 3.4

This weeks APOD is of V838 Mon, the brightest star in the Milky Way as of January 2002. No one knows why but the stars outer surface greatly expanded causing it to brighten. However just as suddenly as it had brightened it seemed to fade. A stellrt flash like this has never been seen before Normally supernovas and novas expel matter out into space. However the stars flash appears to expel material into space, it is actually an light echo moving outward. V838 Mon lies about 20,000 light years away near the constellation Monoceros. The light echo surrounding the star expands to about 6 light years in diameter.

APOD 3.3

This weeks picture is of the First Explorer which was launched 5o years ago on January 31, 1958. This satellite marked the begining of space exploration for the United States. Explorer I was launched by Army Ballistic Missile Agency and weighed only thirty pounds. It orbited the Earth and stopped about a month after it was launched but remained in orbit until March of 1970. The satellite carried instruments to measure temperatures, and micrometeorite impacts, along with an experiment designed by James A. Van Allen, to measure the density of electrons and ions in space. Because of this expiriment it led to the discovery of a belt of high energy electrons and ions trapped in the magnetosphere circling the Earth and now known as the Van Allen Radiation Belt.

APOD 3.2

This weeks APOD is about these two supernova shells and wether or not they are related. To find out they used an 8 meter telescope, the Gemini Telescope, one of the biggest telescopes in the world, on top of a mountain in Chile. They used the telescope to look at the double-lobed cloud DEM L316. The image of the two shells is extremely detaild and led astronomers to believe that the two had nothing to do with eachother. The first supernova is a Type I which means it's the result of a white dwarf exploding. The seond supernova is a Type II which is the result of massive normal star exploding. Because the two processes are on two totally different time schemes the two most likely did not form together and are therefor not physically associated. The two clouds are now thought of to be superposed by chance!

Observation 2.3

Date: January 7th 2008

Time: 8:20 - 10:10 PM

Location: Boca Grande

Sky Conditions: Clear skies, an hour in partially cloudy

Instruments used: Naked eye, binoculars

Planets: Mars, Jupiter

Bright stars noted: Polaris, Rigel, Betelgeuse, Fomalhaut

Constellations noted: Andromeda, Gemini, Aries, Ursa Minor, Pegasus, Taurus, Cepheus, Pegasus, Cassiopeia, Pisces, Cetus, Pisces Austrinas

Sky objects: M82, M101

Other: Milky Way

Parts of Englewood as well as Boca Grande are excellent places to observe the sky. There is limited light pollution and there is almost always clear skies (at least every time I'm there). I started observing the sky in the West and worked my way to the North and then so on. It was much harder identifying contellations and stars I knew because there were sooooo many visible stars compared to any viewing I have ever done in Sarasota. After about an hour or so the clouds came out for about ten minutes or so and the only things visible were Orion's Belt and a few miscellanious stars. We should do a star gazing session around here sometime!

Giuseppe Piazzi

Giuseppe Piazzi was an Italian Theatine monk, mathematician, and astronomer. He was born in Ponte in Valtellina. He taught philosophy for a time at Genoa and mathematics at the new University of Malta while it lasted. In 1780 he was called to the chair of higher mathematics at the academy of Palermo. There he soon obtained a grant from Prince Caramanico, Viceroy of Sicily, for an observatory. He established his observatory at Palermo, and it is now called the Osservatorio Astronomico di Palermo "Giuseppe S. Vaiana".
Giuseppe began observations in May of 1791, and the first reports were published as early as 1792. Soon he was able to correct errors in the estimation of the obliquity of the ecliptic, of the aberration of light, of the length of the tropical year, and of the parallax of the fixed stars. He also thought it was necessary to revise the exsisting catalogue of stars to determine their exact postitions. So in 1803 he published a list of 6784 stars and in 1814 he published a second catalogue containing 7646 stars. Both lists were awarded prizes by the Institute of France.
While looking for a small star mentioned in one of the earlier lists he made his great discovery of the first known planetoid. At first he thought it was a fixed star, but once he noticed that it moved, he became convinced it was a planet, or as he called it, "a new star". But since he was unsure of his discovery he announced to the scientific world he had discovered a comet. These few but exact measurements enabled astronomer Carl Friedrich Gauss to calculate the orbit and to find that this was a new planet, between Mars and Jupiter. Piazzi's discovery confirmed the so-called "Titius-Bode's law", which predicted the existence of a fifth planet between the orbit of Mars and Jupiter.
Piazzi proposed the name of Ceres Ferdinandea, in honor of his king. Over 600 of these so-called planetoids have since been located within the same space. Ceres turned out to be the first, and largest, of the asteroids existing within the Asteroid Belt. However, under the terms of a 2006 IAU resolution, Ceres can be called a dwarf planet.
The king desired to give Piazzi a gold medal, in commemoration, but the astronomer requested the privilege of using the money for the purpose of a much-needed equatorial telescope. Then later in 1812 he received the commission to reform the weights and measures of Sicily in accordance with the metric system. Piazzi was a brilliant astronomer whose discoveries led to the discovery of Uranus as well as other asteroids near Earth.

Works Cited

Cunningham, C. J.. The First Asteroid. 2001. Star Lab Press. 7 January 2008.

Fox, William. "Giuseppe Piazzi." New Advent. 2007. Catholic Encylcopedia. 7 January 2008. http://www.newadvent.org/cathen/12072d.htm

APOD 3.1

IC 342 is a prominent beautiful galaxy that is hidden in our night sky by the Milky Way Galaxy. If the gas and clouds from the Milky Way did not cover IC 342 it would most certainly be very popular. Ic 342 is 7 million light years away and is located in the constellation of Camelopardalis. Its appearance in the sky makes his galaxy a prime target for studies of star formation and astrochemistry. IC 342 belongs to Maffei I group of galaxies. The galaxy was discovered by W.F. Denning in 1895. Without the Milky Way Galaxy covering it this galaxy would have been discovered much earlier because of its extreme brightness, about 2.4 magnitude.