APOD 2.1

October 28, 2010.                 Mirach's Ghost.

The photo shown above is of the gallaxy known to astronomers as Mirach's Gallaxy for its location along the line of sight to the bright star Mirach.  The gallaxy itself is very faint and fuzzy, so it is hard to make accurate observations about it, however its presence is still well known to astronomers.  Mirach's Ghost, or NGC 404, is actually a dwarf lenticular gallaxy in the constellation Andromeda, however the glare from Mirach or Beta Andromeda located only a few arc seconds away inhibits clear view.  Mirach is a red giant star, and is suprisingly much larger than our sun, however it is much cooler so while it may shine brighter, it does not produce nearly as much heat.  The gallaxy got its name from the diffraction spikes caused by the glare of the bright star when viewed by astronomers.  In the picture, the bright center star is Mirach, and above and to the right, the smaller more distant blur is NGC 404, or Mirach's Gallaxy, estimated to be around 10 million light years away.

APOD 1.8

October 18th, 2010.    It came from the Sun.

This picture was taken by the SOHO satellite that orbits the sun. Rising from behind the sun is a solar prominence, or a bright feature extending outward from the sun in a loop shape. Prominences are anchored to the sun in the photosphere and extend toward the Corona.  The technical definition of a prominence is a thin cloud of solar gas held to the surface of the sun (in the photosphere as previously stated) as a result of the Sun's magnetic field.  Prominences are closely related to filaments, however they are differientiable based on their position around their sun which in turn affects their coloring. Filaments are cooler than air and thus appear dark, however prominences like the one shown above are located on the surface edge of the sun and appear brighter than the space behind them.  There are two types of prominences; they can either be quiescent or eruptive. A quiescent prominence lasts up to a few months, but an eruptive prominence like the one in the picture above typically only last a few hours.  After this time, they will erupt causing a Coronal Mass Ejection (CME) and dispersing hot gas throughout the Solar System.  As our sun continues to approach solar maximum in its cycle over the next few years, many more filaments and prominences are expected to occur.

Observations Week of 10/18/10

October 18, 2010.

Observing from my back porch in northern Sarasota.
Viewing time 8:05 p.m.

In the east was a very bright waxing gibbous moon, approaching a full moon in a few days.  Even further east and a tiny bit south of the moon was a very bright object that looked to be in two parts. At first I assumed that it was the International Space Station but after consulting with Heavens Above I realized that the ISS was only visible from around 6:40-6:45p.m. two hours previous. Therefore, I believe that the bright portion is possibly Jupiter with the lesser magnitude portion possibly a faint outline of Uranus located very close by.

October 22, 2010.

Observing from restaurant parking lot in northern Sarasota.
Viewing time 8:30 p.m.

In the East as we left the restaurant was a very full moon that brought about a family discussion about whether it was full or not. This forced us to go home and research to find that the moon was actually in its last waxing gibbous state, and tomorrow would be the full moon.

October 23, 2010.

Observing from my driveway in northern Sarasota.
Viewing time 8:00 p.m.

Finally, the long awaited day of the full moon had come.  The moon was very bright to the due east and illuminated much of the sky around it making it difficult to see many other stars around.  Along with this, many lights from my neighbor's houses were blocking further observation of lesser magnitude stars.

Johannes Kepler Biography

William Martin

Mr. Percival

Astronomy Pd. 1

October 15^th, 2010

Johannes Kepler Biography

Johannes Kepler was born in 1571 in a town called Weil in Wurmberg, now located in Southwestern Germany.  In his early life, Kepler was very interested in religion and received a degree in theology, later entering the University of Tubingen, at the time renowned for its Protestant teachings, where he graduated in 1591. At this school, Kepler became very advanced in mathematics, and went on to take a teaching position at a small school in Austria. However, his small numbers of students gave Johannes much free time to pursue his newfound interest, astronomy.

A dedicated believer in Copernicus’s heliocentric theory, Kepler tested many of Copernicus’s observations for accuracy and accounted any errors and discrepancies to miscalculations or observations but was unwilling to move away from Copernicus’s theory. In 1600, an astronomer by the name of Tycho Brahe noted Kepler for his skills in mathematics and invited him to Prague to use Brahe’s observations to calculate the distances of the planets.  Brahe was known for taking some of the most consistent and detailed observations on record, and thus when he passed away shortly after in 1601 he left much for Kepler to work with and analyze. 

In 1610, Kepler got word of Galileo’s recent invention of the telescope and made a version for his own personal use shortly after. With this, he confirmed Galileo’s assertion of Jupiter’s planets and verified many other observations, taking some of his own along the way.

  Using his observations, Kepler finally strayed from the common beliefs of Aristotle and Copernicus and came to the conclusion that planets orbit in ellipses rather than circles. After recalculating the distances of the planets using Brahe’s observations, the numbers seemed to fit and Kepler had made one of the most important discoveries in astronomical history.

Using his newly found discovery, Kepler was able to establish three main laws, widely known as the laws of planetary motion. The first law states that the orbits of the planets are ellipses, with the sun as one focus of the ellipse.  The second law explains that the line joining the planet to the sun sweeps out equal areas in equal times as the planet travels around the ellipse. Kepler’s final law stated that the ratios of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes in the semi major axes, or better known P^2 = R^3.

           Although he died in 1630, because of his great contributions to the field of astronomy, Kepler is still regarded as one of the most important astronomers and mathematicians to ever live.  The impacts he made still form the backbone of astronomy and are used on a regular basis.

APOD 1.7

October 9th, 2010.                Global Star Cluster NGC 6934

What an amazing picture this was! Even before looking through the rest of this week's pictures I knew that I would choose this image for my weekly post. This picture is of a globular star cluster, or a spherical collection of thousands of stars that orbit a galactic core and are bound by the force of gravity. There are two types of star clusters, globular and open. While open clusters only have up to a few hundred stars loosely packed, as we can see from the picture globular star clusters have up to millions of stars packed tightly together. Oddly enough, many of the stars seen are even older than the galactic disk that they orbit. NGC 6934 was discovered in 1785 and estimated to be about 50 kilo-light years. This core happens to lay in the center of Delphinus, the Dolphin constellation that we learned about which contains Job's coffin.  This picture was taken from the well known Hubble Telescope's Advanced Camera for Surveys and spans over 50 light years, focusing on stars estimated to be over 10 billion years old.

APOD 1.6

October 8th, 2010.  Two Planet Opposition.

This picture demonstrates an important concept in astronomy that we discussed in our previous chapter, opposition.  Opposition means that the planets were aligned opposite of the sun with Jupiter and Uranus orbiting close enough to be seen in Earth's sky (still thousands of millions of kilometers). The conversion factor website linked to the picture was very interesting as it really put the absurd numbers of light years we hear into perspective so that we can accurately gauge about how large these numbers actually are.  Uranus is the planet located in the top right with the greenish tint, and the two minuscule dots above it are its moons. Theses are only 2 of Uranus' 5 larger moons and are named Oberon and Titania for characters in Shakespeare's A Midsummer Night's Dream. The larger planet located on the right side of the photograph is Jupiter which is surrounded by its 4 Galilean Satellites named after Galileo's observations of the orbiting moons. Starting from the bottom left and working up the the top right, the names of the moons are respectively; Callisto, Europa, Io, and on the opposing side of the planet rests Ganymede. 

APOD 1.5

September 26th, 2010. Arp 188 and the Tadpole's Tidal Tail.

This picture represented the kind of sight that first initiated my interest in astronomy. A swirling galaxy followed  by a long tail like feature demonstrate the endless possibility of events that can occur in our solar system.  This picture was taken by the well known Hubble Space Telescope's Advanced Camera for Surveys. Since the Hubble is in orbit, it allows for much closer and more precise pictures of whatever it is targeting in its view.  This picture is actually of the spiral galaxy Arc 188,  or better known as the Tadpole Galaxy due to its resemblance of the creature.  Its long tail is made of bright blue star clusters and spans for over 280,000 light years.  It giant galaxy is believed to have formed by a smaller galaxy crossing paths with the larger circular galaxy, and thus the a huge gravitational force was created. This pulled all of the stars and dust particles out of the spiral galaxy, and as a result created what we refer to as the "tail" on the tadpole. The intruder galaxy that nearly collided with the Tadpole galaxy now remains in orbit within the spiraling arms of the Tadpole.  However, as during the life span of a Tadpole, this galaxy will also mature and lose its tail as the stars cluster begin to form smaller and smaller satellites.

Astronomer Project Sources: Johannes Kepler

Works Cited

"Kepler, Johannes (1571-1630)." World of Earth Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner.     
              Vol. 1. Detroit: Gale, 2003. 333-335. Gale Virtual Reference Library. Web. 1 Oct. 2010.

"Kepler, Johannes (1571–1630)." Encyclopedia of European Social History. Ed. Peter N. Stearns. Vol. 6:  
             Biographies/Contributors. Detroit: Charles Scribner's Sons, 2001. 173-174. Gale Virtual Reference 
            Library. Web. 1 Oct. 2010.

BARKER, PETER. "Kepler, Johannes (1571–1630)." Europe, 1450 to 1789: Encyclopedia of the Early 
            Modern World. Ed. Jonathan Dewald. Vol. 3. New York: Charles Scribner's Sons, 2004. 398-401. 
           Gale Virtual Reference Library. Web. 1 Oct. 2010.