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Bubble Nebula
Bruce Sawinski

Bubble Nebula

This is the Bubble Nebula, which is also know as the Caldwell C11, and NGC 7635. This Nebula is located in an emission Nebula in the constellation of Cassiopeia. The star is roughly 7100 light years away. The bubble shape is created by stellar winds from a very hot 8.7 magnitude young central star. The star is not the center of the Bubble because it is much denser at the top left. The glow comes from the ultraviolet radiation from the bright star that is near the top of the bubble. These winds are moving at about 2000 km per second. The Nebula is also located near a giant molecular cloud which gives it more of the outer shape, the bright star emits ultraviolet radiation which then reacts with the hydrogen atoms, ionizing them, and this creates the glow of this molecular cloud. This Nebula was discovered in 1787 by Friedrich Wilhelm Herschel.

This Nebula is in the shape of a Bubble, that is where it gets its name from. You can see the main shape and then you can see other red hydrogen gas that are to the left and above the main object. You can see at the top of the bubble there is a very bright area this is created by a star that is in the center of that bright area. This is due to a very bright star as mentioned above. The illumination is so great that it makes this area appear to be very saturated because of the way that I choose to do the image, this allowed me to show the outer red clouds. The radiation from this star is sent out and then creates the red that you can see in the rest of the object because these particles take in the radiation and then come back together. The bluer circular object in the lower right is a star and because of the bright blue color you can tell that it is a very hot star. The distance to this object is estimated to be 7100 light years; we find a maximum angular size of 15 arc minutes, which corresponds to a linear size of 11 light years.


Kepple, George Robert; Sanner, Glen W. (1998), The Night Sky Observer's Guide, 1, Willmann-Bell, Inc., pp. 108–109, ISBN 0-943396-58-1

Murphy, John. John Murphy Astrophotograhy. N.p., 2010. Web. 8 Nov. 2011. <>.

Right Ascension (J2000) 23:20:45
Declination (J2000) 61:12:42
Filters used B (Blue), C (Clear), R (Red), V (Green)
Exposure time per filter B, V, R and C (60s x 5)
Date observed October 12, 2011



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