The Bubble Nebula, NGC 7635, is an emission nebula found in the Cassiopeia constellation. Approximately 11,000 light years away, it is visible with the help of only a small telescope. Friedrich Wilhelm Herschel discovered this nebula in 1787 and it was coined the “Bubble Nebula” because of its distinct bubble shape. The “bubble” is formed by the incredibly hot and massive star on the inside of the nebula which blows powerful ionized gas into the interstellar space. An emission nebula is one which emits light; the bubble glows where it is radiated, or excited, by the heat from the star.
The bubble is approximately 10 light years across, and the star that is blowing out the stellar winds and exciting the nebula is in the upper half of the bubble. The red region around the bubble is an H II region nebula that consists of ionized hydrogen. When the Hydrogen emits its light in these regions it is red, making these regions easy to identify.
Bennett, Jeffrey, Megan Donahue, Nicholas Schneider, and Mark Voit. The Cosmic Perspective. 6th ed. San Francisco: Addison-Wesley, 2010. 588.
Jurasevich, Dave. "The Bubble Nebula." Astronomy Picture of the Day. Ed. Robert Nemiroff and Jerry Bonnell. NASA, Sept. 2010. Web. 6 Dec. 2010. <http://antwrp.gsfc.nasa.gov/apod/ap100902.html>.
Temple, Craig, and Tammy Temple. "NGC 7635/M52 - The Bubble & The Scorpion." Astronomy. Kalmbach Publishing Co. , 8 Nov. 2010. Web. 6 Dec. 2010. <http://cs.astronomy.com/asycs/media/p/458069.aspx>.
|Right Ascension (J2000)||23:20:42|
|Filters used||blue(B), green(V), red(R), and clear(C)|
|Exposure time per filter||60 seconds in BVRC|
October 28, 2010 (C)