Sunday, December 12, 2010

APOD 2.6

Picture from December 9, 2010

This is the spiral galaxy M81, in the constellation of Ursa Major (the one with the Big Dipper). It's approximately 11.8 million light years distant, but is one of the brightest galaxies in Earth's night sky. Above and to the left, a dwarf companion galaxy to M81 called Holmberg IX can be seen. More intriguing, however, is the large faint loop structure on the right known as Arp's Loop. The loop was thought to be what is called a tidal tail, or a large band of material separated from M81 by nearby galaxy M82. Recent observations though show that Arp's Loop actually might not be too far from the Milky Way. The loop appears similar to clouds of dust observed just a few hundred light years above the plane of the milky way. Weird.

Monday, December 6, 2010

Observation 12/6/10

Tonight I observed Cassiopeia from my neighborhood's community center at about 7:50 PM. I was facing NNW, looking about 70 degrees up. Specifically, I observed the Worm Asterism, which from my position was visible in its classic "M" shape.

Sunday, December 5, 2010

APOD 2.5

This galaxy, called M33, lies in the constellation of Triangulum. It is known more commonly as the Triangulum Galaxy or the Pinwheel Galaxy. It's over 50,000 light years across, making it the third largest galaxy in the Local Group (a collection of galaxies relatively close to our own), after the Andromeda Galaxy (M31) and the Milky Way. An interesting fact about the Triangulum Galaxy is that it is thought to be a satellite of the Andromeda Galaxy, in that it appears to revolve around the Andromeda Galaxy. Pretty hard to imagine an entire galaxy orbiting a whole other galaxy, eh? Also, that bright pink spot near the lower right is NGC 604, the brightest star forming region in the Triangulum Galaxy. The galaxy is actually a fairly important astronomical tool as well. Because of the measurements we have made of its variable stars, we can use it to measure distances across the cosmos.

Friday, November 19, 2010

APOD 2.4

Picture from November 8, 2010


There is a lot going on in this large 10 degree-wide picture around the constellation of Taurus. The famous Pleiades star cluster can be seen in the upper left. It is known for it's reflection nebulae, which consist of dust particles that scatter the light, creating the bluish glow around the cluster. Also in the picture is less popular LBN 777, the nebula near the center that resembles the head of a bird. Another nebula, VdB 27, is visible in the lower right, along with nearby star RY Tau.

Friday, November 12, 2010

APOD 2.3


Picture from November 10, 2010

The Fermi satellite orbiting the Earth has, for the past two years, been gathering information on gamma ray emissions across the sky. The results, pictured here, are astounding. The Milky Way appears to have two large bubbles (the red and white splotches above and below the center of the image) protruding from its center emitting gamma rays outwards. The bubbles can also be seen to emit x-rays as well as microwaves. The bubbles span some 50,000 light years from top to bottom, a length that rivals the size of the galaxy itself. Little is known about these huge bubbles. How did they originate? What causes them? This reflects the fact that we still have much left to learn about the phenomena of our own galaxy.

Thursday, November 11, 2010

Great Worldwide Star Count

I reported that, at 27.2097 degrees latitude and -82.47616 degrees longitude on November 11 at 7:45 PM, the constellation of Cygnus was visible with a limiting magnitude of 3.

Friday, November 5, 2010

APOD 2.2


Picture from November 2, 2010

Solar flux tubes, or spicules, are big "pipes" of hot gas on the sun held in place by its magnetic field. An average size spicule is about as wide as an average state in the US and as long as the Earth's diameter. This picture, one of the highest resolution of it's kind to date, depicts such spicules converging at a sunspot in the bottom right. The lifespan of a spicule was found to be about 5 minutes, after which the gas falls back to the sun's surface. How exactly these spicules come about is still a mystery, but remains an active topic of research. The sun's importance to life on Earth is unquestionable, so it would behoove us to study the sun as much as possible.

Thursday, October 28, 2010

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.

Saturday, October 23, 2010

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.

Friday, October 22, 2010

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.

Friday, October 15, 2010

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.

Thursday, October 14, 2010

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.

Friday, October 8, 2010

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!)

Friday, October 1, 2010

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.

Friday, September 24, 2010

APOD 1.4






Picture from September 20, 2010

This APOD picture shows the aurora borealis over Norway. Also called the northern lights, this wondrous phenomenon actually depicts Earth's magnetic field struggling to ward off charged particles from the sun. Since the magnetic field is weakest near the poles, some of these particles get through and collide with air molecules high in the atmosphere, which causes the light show. Because the phenomenon requires both a magnetic field and a relatively substantial atmosphere, it does not occur on bodies such as the moon, but can be observed near the poles of planets like Jupiter and Saturn. In those cases however, the charged particles come less from the sun and more from the planets' moons.

Tuesday, September 21, 2010

Observation: 9/20/10

I observed the constellation Scorpius along with its alpha star, Antares, at about 9:00 PM EDT from my backyard. It was in the southern sky with an altitude of around 40 degrees. Due to the brightness of the waxing gibbous moon, I could see only three stars of the constellation clearly (including Antares) with the naked eye. Using binoculars, I could see around seven.

Friday, September 17, 2010

APOD 1.3


Picture from September 14, 2010

This picture, taken by the Hubble Telescope, depicts a strange phenomenon. Nobody is sure what caused that spiral shape to the left, much less why it seems to glow. The current hypothesis is that it is the proto-planetary disk (basically a mass of swirling gas and dust left over from star formation) of a young binary star system (LL Pegasi). The spiral seems to be expanding, adding another layer approximately every 800 years. Coincidentally, this is roughly the time it would take for the stars to orbit each other. This also shows that although our knowledge of the universe is constantly expanding, there is still much we have yet to learn.

Friday, September 10, 2010

APOD 1.2


Picture from  September 10, 2010

This picture is of remnants of a supernova in the northwestern edge of the constellation of Vela. The supernova was the result of the death of a large star around 11,800 years ago. The remnants are about 800 light years away, so we are actually viewing the region as it was 800 years ago. Although it might be a beautiful sight, actually going near the area might be dangerous. The star left behind a pulsar, a stellar core that spins very rapidly and emits large amounts of radiation. It is fortunate that we can observe the majesty of these remnants from a safe distance.

Monday, September 6, 2010

APOD 1.1

On picture from August 30, 2010

When we examine the area in the vicinity of the Comanche Outcrops on Mars, there are rocks containing carbonates that would have dissolved in acidic water. Therefore, the water on Mars could have been closer to a neutral pH. I believe this is strong evidence that life as we know it once existed on Mars. This is a fascinating prospect, hence why I chose this picture. Martian exploration seems to be very important in terms of gaining insight into whether there's life on other worlds and what that life might be like. This, in turn, could be very important in our ultimate understanding of the universe.