This is comet 17P/Holmes on the evening 11/28/07. It has been nine days since the image below and the comet is still expanding!
This is comet 17P/Holmes on the evening 11/19/07. It continues to expand. The star Mirfak (Alpha Perseus) can be seen shining through the comet on this night.
This image can also be seen in the 2009 Official Calendar of the Vatican Observatory for the month of October.
This is comet 17P/Holmes on the evening of 11/14/07. Astronomers estimate that this expanding ball of dust and gas is now the largest object in the solar system! The faint tail seen in the image below has detached from the body of the comet a few days ago and has faded from view. The bright area towards the upper right is glow from the star Mirfak (Alpha Perseus).
This image shows comet 17P/Holmes on the evening 11/02/07. In addition to the head, a faint tail can be seen exiting toward the top and right. The comet continues to grow in size though not quite as much as the comparison images below would suggest. This image was taken with a different camera setup that has roughly 1/2 of the field of view as the images below. To suggest an idea of the size of the comet on this night, four full moons could easily be placed in this image.
This image shows comet 17P/Holmes on the evening 10/28/07. It has grown significantly in size from the 10/24/07 image below. In addition to the nucleus, background stars can be see shining though the comet.
This image shows comet 17P/Holmes on the evening 10/24/07. At best it can be described as a bright dot that is somewhat larger than the surrounding stars.
This image shows the location of comet 17P/Holmes on the evening 10/24/07. During the previous 24 hours the comet had undergone a brightness change that moved it from the realm of large telescopes to naked eye visibility. Though the comet is bright, no tail is visible. This makes it hard to distinguish from the stars in the image above. However if you mouseover the image, constellation lines marking Perseus will appear and 17P/Holmes will be circled.