http://www.phys-astro.sonoma.edu/brucemedalists/hale/
http://www.mwoa.org/hale.html.%20Web.%2021%20Jan.%202010.
The Astrophysical Journal Centennial by George E Hale. 1895
Saturday, February 25, 2012
Wednesday, February 22, 2012
Star formation begins when the denser parts of the cloud core collapse under their own weight/gravity. These cores typically have masses around 104 solar masses in the form of gas and dust. The cores are denser than the outer cloud, so they collapse first. As the cores collapse they fragment into clumps around 0.1 parsecs in size and 10 to 50 solar masses in mass. These clumps then form into protostars and the whole process takes about 10 millions years.
There are two common ways this can happen: it can either collide with another dense molecular cloud or it can be near enough to encounter the pressure caused by a giant supernova. Several stars can be born at once with the collision of two galaxies.
Many of the most interesting infrared objects are associated with star formation. Stars form from collapsing clouds of gas and dust. As the cloud collapses, its density and temperature increase. The temperature and density are highest at the center of the cloud, where a new star will eventually form. The object that is formed at the center of the collapsing cloud and which will become a star is called a protostar. Since a protostar is embedded in a cloud of gas and dust, it is difficult to detect in visible light. Any visible light that it does emit is absorbed by the material surrounding it. Only during the later stages, when a protostar is hot enough for its radiation to blow away most of the material surrounding it, can it be seen in visible light. Until then, a protostar can be detected only in the infrared. The light from the protostar is absorbed by the dust surrounding it, causing the dust to warm up and radiate in the infrared. Infrared studies of star forming regions will give us important information about how stars are born and thus on how our own Sun and Solar System were formed.
Websites:
http://www.ipac.caltech.edu/outreach/Edu/sform.html
http://abyss.uoregon.edu/~js/ast122/lectures/lec13.html
http://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve/
There are two common ways this can happen: it can either collide with another dense molecular cloud or it can be near enough to encounter the pressure caused by a giant supernova. Several stars can be born at once with the collision of two galaxies.
Many of the most interesting infrared objects are associated with star formation. Stars form from collapsing clouds of gas and dust. As the cloud collapses, its density and temperature increase. The temperature and density are highest at the center of the cloud, where a new star will eventually form. The object that is formed at the center of the collapsing cloud and which will become a star is called a protostar. Since a protostar is embedded in a cloud of gas and dust, it is difficult to detect in visible light. Any visible light that it does emit is absorbed by the material surrounding it. Only during the later stages, when a protostar is hot enough for its radiation to blow away most of the material surrounding it, can it be seen in visible light. Until then, a protostar can be detected only in the infrared. The light from the protostar is absorbed by the dust surrounding it, causing the dust to warm up and radiate in the infrared. Infrared studies of star forming regions will give us important information about how stars are born and thus on how our own Sun and Solar System were formed.
Websites:
http://www.ipac.caltech.edu/outreach/Edu/sform.html
http://abyss.uoregon.edu/~js/ast122/lectures/lec13.html
http://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve/
Wednesday, February 15, 2012
APOD 3.4
APOD 3.4: Belt of Venus: http://apod.nasa.gov/
Although this looks like the typical sky during twilight, the slightly off coloration of the sky near the horizon is what's known as the Belt of Venus. This coloring can be seen in just about every direction during sunrise and sunset. In the belt of Venus, the atmosphere reflects light from the sun, creating the red-pink color shown in this picture. Below the belt, very little light is reflected, thus causing the area slightly above the horizon to appear somewhat darker. This is a really beautiful picture of the sky, and I will definitely have to start paying more attention to the sky during twilight hours!
Monday, February 13, 2012
Observations 2/12
Observations: Feb. 12 2012: 7-11pm
Unfortunately due to my car being serviced, I was unable to drive out to the Stargaze, yet I went to observe the stars in my yard nonetheless.I observed constellations, such as Orion, Cassiopoeia, Canis Major, and some others. Using my fist, I estimated the distance between Jupiter and Venus. I estimated the distance between them to be about 16 degrees. I was also spotting Jupiter with my telescope and various M object in its surrounding area. I was also able to identify a few first magnitude stars that were visible. I will make sure to be able to be able to go to the next Star Gaze.
Friday, February 3, 2012
APOD 3.1
APOD 3.1 Witch Head Nebula: http://apod.nasa.gov/apod/ap120117.html
A reflection nebula reflects light from nearby stars. This nebula lies 1000 light years away and is associated with the bright star Rigel which is located in the constellation, Orion. The fine dust located in the With Head Hebula, reflects Rigel's light. The blue color this nebula appears to be is not only from the apparent blue color of the star but also because the dust can moer effecently reflect blue than red. This same effect is displayed in the blue sky every day, because of the molecules(nitrogen and oxygen) in the Earth's atmasphere.
A reflection nebula reflects light from nearby stars. This nebula lies 1000 light years away and is associated with the bright star Rigel which is located in the constellation, Orion. The fine dust located in the With Head Hebula, reflects Rigel's light. The blue color this nebula appears to be is not only from the apparent blue color of the star but also because the dust can moer effecently reflect blue than red. This same effect is displayed in the blue sky every day, because of the molecules(nitrogen and oxygen) in the Earth's atmasphere.
APOD 3.2 Rover on Mars
Rover on Mars APOD 3.2: http://apod.nasa.gov/apod/ap120125.html
As winter was approaching on Mars in the southern hemisphere, the Opportunity Rover did not know where to go. Without the sun and under freezing conditions, Opportunity's batteries could be wasted. Therefore, Opportunity was instructed to climb onto the 15 degree incline on Greenley's Haven. Greenley Haven is visible from a far away distance.
As winter was approaching on Mars in the southern hemisphere, the Opportunity Rover did not know where to go. Without the sun and under freezing conditions, Opportunity's batteries could be wasted. Therefore, Opportunity was instructed to climb onto the 15 degree incline on Greenley's Haven. Greenley Haven is visible from a far away distance.
APOD 3.3 Aurora Borealis
Aurora Borealis APOD 3.3 http://apod.nasa.gov/apod/ap120128.html
There is an eerie green light that eminates from this planet, which is covered in snow and tall pine trees. Of course this is actually Earth and the surrounding stars are above the horizon. The pale greenish illumination you are seeing is from the Northern Lights, also known as Aurora Borealis. The display seen was triggered when a coronal mass ejection lol, produced a strong geomagnetic storm. Recently, increasing solar activity has caused auroral displays to become more widespread. Some of these include Aurora Australis and the Southern Lights.
There is an eerie green light that eminates from this planet, which is covered in snow and tall pine trees. Of course this is actually Earth and the surrounding stars are above the horizon. The pale greenish illumination you are seeing is from the Northern Lights, also known as Aurora Borealis. The display seen was triggered when a coronal mass ejection lol, produced a strong geomagnetic storm. Recently, increasing solar activity has caused auroral displays to become more widespread. Some of these include Aurora Australis and the Southern Lights.
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