Part I: You are shown the map of the night sky above, which is in galactic coord
ID: 1782154 • Letter: P
Question
Part I: You are shown the map of the night sky above, which is in galactic coordinates. Is the object indicated by the green dot likely to be inside or outside the Galaxy? If it is inside the Galaxy, is it near the center of the Galaxy or far away from it? Explain.
Part II: Astronomers have looked at the green dot object (which is called IC 443, or the Jellyfish Nebula) in a combination of radio (shown as green), visible light (shown as red), and X-rays (shown as blue) and put them together in the image above. (The big puffball was left behind after a massive star went supernova some ten-thousand years or so ago). Are the colors in the image "real?" Explain why or why not. Given that a combination of red, blue, and green on a computer screen makes white, what do you think is true about the parts of the nebula that look greenish-white? Blue-white?
Explanation / Answer
Part 1
The proper motions in right ascension and declination are made equivalent for straightforward calculations of various other stellar motions. Position angle is related to these components by, Motions in equatorial coordinates can be converted to motions in galactic coordinates, for the majority of stars seen in the sky, the observed proper motions are usually small and unremarkable.
The ecliptic coordinate system specifies positions relative to the Earths orbit, besides the equatorial and ecliptic systems, some other celestial coordinate systems, such as the galactic coordinate system, are more appropriate for particular purposes
Part 2
Unicorns and roses are usually the stuff of fairy tales, but a new cosmic image taken by NASA’s Wide-field Infrared Explorer (WISE) shows the Rosette nebula located within the constellation Monoceros, or the Unicorn.
This flower-shaped nebula, also known by the less romantic name NGC 2237, is a huge star-forming cloud of dust and gas in the Milky Way Galaxy. Estimates of the nebula’s distance vary from 4,500 to 5,000 light-years away.
At the center of the flower is a cluster of young stars called NGC 2244. The most massive stars produce huge amounts of ultraviolet radiation, and blow strong winds that erode away the nearby gas and dust, creating a large, central hole. The radiation also strips electrons from the surrounding hydrogen gas, ionizing it and creating what astronomers call an HII region.