Comet Lulin appears to have two tails. The second tail is called an anti-tail. The reason why we see two tails, is because the comet lies in the same orbital plane as earth. The above diagram shows a typical comet viewed from above in this instance, which has a dust tail streaming out behind it as it moves around its orbit clockwise in this diagram. The solar wind causes the comet to have an ion tail that extends away from the comet in the opposite direction from the sun. When we see two tails, it is because the dust tail is visible to us on one side of the comet, and the ion tail is visible to us on the other side of the comet. It is all a matter of the viewing angle, which is unusual for this comet. This diagram shows the position of the comet relative to the earth on February 7, 2009, and I have an image taken on that date that shows how the comet appeared from our perspective.
Comet C/2007 N3 (Lulin)
RA: 14h 32m 10s Dec: -14d 12' 28" (J2000)
February 7, 2009
Complete list of images.
Description of equipment used to acquire images.
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