APOD 2.1

Picture from October 28, 2010

This APOD picture depicts a bright star known as Mirach. Mirach, the beta star in the constellation of Andromeda, is a red giant about 200 light years away. Another object of interest in the photo is a galaxy known as NGC 484, or Mirach's Ghost, which can be seen as the blurry spot to the upper right of the star. The galaxy, some 10 million light years distant, is given its ghostly moniker due to the fact that it often appears dim and fuzzy when seen through a telescope next to Mirach. This is because bright light causes certain aberrations, or distortions, to telescopic images. Such aberrations can be seen here in the form of the glare and the colorful lines (called "diffraction spikes") that seem to be erupting from the star.

Observation: 10/23/10

This is the constellation of Lyra, as seen from outside the community center in my neighborhood at around 8:40 PM. The constellation was in the southern sky, about 70 degrees up. The brightest star in the photo is Vega, the alpha star of the constellation. The star to the upper right of that is Epsilon Lyrae, or "the Double Double." Only two of its components can be seen here though, as discerning all 4 stars would require a telescope. The star in the bottom left is Gamma Lyrae, and just to the right of that (although not visible here) would be M57, the Ring Nebula.

APOD 1.8

 

 Picture from October 21, 2010

This is a picture of the planetary nebula MWP1, 4,500 light years away in the constellation of Cygnus. Planetary nebulae don't have anything to do with planets (the name comes from how they looked through telescopes back when they were first discovered in the 18th century). They are actually clouds of ionized gas expelled by dying red giant stars that are turning into white dwarfs. Typically, planetary nebulae only last from 10 to 20 thousand years. However, MWP1 is estimated to be some 150 thousand years old based on its rate of expansion.This makes MWP1 (and the star at its center) an intriguing object of study for astronomers.

APOD 1.7

Picture from October 9, 2010

This spectacular image shows what is know as a globular star cluster. These clusters are gravitationally bound into a spherical arrangement, and the clusters themselves are older than all other bodies in their respective galaxy. They are so old, in fact, that studying these arrangements is one way astronomers can put a lower limit on the age of the universe. In this way, they can be a useful tool for studying how the universe was shaped, and what the early universe might have been like. This particular cluster, NGC 6934, is approximately 50,000 light years away, in the constellation of Delphinus. The stars in the cluster are estimated to be around 10 billion years old.

Biography of Johann Bayer

    Johann Bayer was a German astronomer who did the majority of his work around the turn of the 17th century. He is credited with creating a comprehensive atlas of the stars, the Uranometria. The atlas was the first of its kind to represent the entire sky, as it was the first to include the stars around the South Pole. Bayer is also invented the nomenclature used for identifying stars visible to the naked eye, which is still the convention in modern astronomy.
    Bayer was born in Rhain in the German region of Bavaria in the year 1572. Twenty years later he enrolled in Ingolstadt University as a student of philosophy. He eventually received a law degree and moved to Augsburg. His interest in astronomy, however, persisted, and he published the Uranometria, his atlas of the heavens, on September 1, 1603. It contained 2,000 stars (1,200 of which were taken from the catalog of Tycho Brahe) in 49 constellations. He received 150 gulden from the city council of Augsburg for dedicating the atlas to two high-ranking citizens. Although the Uranometria was the most encompassing stellar atlas of its time, it was not without its flaws. For example, he labeled a part of a constellation the left side, where all astronomers before him had called it the right, which caused confusion among astronomers using the atlas.
    What is considered Bayer’s more significant achievement, however, is the nomenclature system he devised for designating stars visible to the naked eye. The system in place for identifying individual stars prior to Bayer’s method relied on verbal descriptions of the stars in each constellation. This was confusing for astronomers and often subject to much ambiguity. Bayer, wanting a more effective method, decided to assign each star in each constellation a letter of the Greek alphabet, usually based on decreasing magnitude. (for constellations with more than 24 stars, Latin letters were resorted to). He would then name the star that letter followed by the constellation it was in. For example, the two brightest stars in the constellation of Gemini are named Alpha Gemini and Beta Gemini respectively. Some stars, such as Alpha Centauri (the brightest star in the constellation Centaurus), were only first (carefully) observed in Bayer’s time, and are therefore only known by the names designated by this system. The system is still in use today, but Roman numerals are being implemented as more stars are discovered.
    Though Bayer was successful overall as an astronomer, not all of his ideas were widely adopted. For instance, Bayer once proposed renaming the constellations based on the Bible, with northern hemisphere constellations getting names from the New Testament, and the southern hemisphere constellations getting names from the Old Testament. This, of course, never achieved widespread acceptance.
    Johann Bayer died a bachelor in the year 1625, but not without leaving his enduring mark on modern astronomy.

APOD 1.6

Picture from October 5, 2010

This picture depicts two major nebulae in the constellation of Orion, the Horsehead Nebula and the Orion Nebula. Nebulae are regions of the cosmos where stars are born. They consist of very large clouds of hydrogen (and some other compounds), which will, in many areas of the nebula, compress due to gravitational forces to form new stars. In this way, nebulae are the epitome of both form and function. These particular nebulae are some 1,500 light years away, and to give you an idea of how big nebulae actually are, the Orion Nebula is about 24 light years across (that's greater than the distance from the Earth to Gliese 581g!)

Astronomer Biography Sources

"Bayer, Johnann." Complete Dictionary of Scientific Biography. Vol. 1. Detroit: Charles Scribner's Sons, 2008. 530-531. Gale Virtual Reference Library. Web. 1 Oct. 2010.

Norton, Stephen D. "Johann Bayer." Science and Its Times. Ed. Neil Schlager and Josh Lauer. Vol. 3: 1450 to 1699. Detroit: Gale, 2001. 361-362. Gale Virtual Reference Library. Web. 1 Oct. 2010.

APOD 1.5

Picture from October 1, 2010

This picture, although merely an artist's rendition, represents something that may be very important for astronomers and non-astronomers alike. This is a depiction of what Gliese 581g (pronounced "gleeza"), a newly discovered extrasolar planet, might look like. The planet, only about 20 light years distant and 3.1 times the mass of Earth, is in what astronomer's call "the Goldilocks Zone" of its parent star, Gliese 581 (in the constellation of Libra). This is the area around a star where temperatures and conditions on a planet would be suitable for liquid water, and therefore, for life. There is one catch, however. The planet is thought to be tidally locked, meaning that one side of it always faces it's sun, which will cause perpetual daytime on that side and perpetual night on the other. Temperatures on the daytime side would be hotter than Earth's average temperature, and colder on the nighttime side. Regardless, finding a potentially habitable planet relatively close by could mean that there are many others like it throughout the galaxy.