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The Praesepe cluster lies at about 587 light years and has an estimated age of 650 million years. Praesepe is commonly referred to as the "Beehive" cluster, because its round and fuzzy shape reminds us of a swarm of bees. It is easily visible to the naked eye, and thus known since ancient times. Praesepe is made up of about 100 stars and lies at the center of the Cancer constellation.
A cluster is a group of typically 100 stars that are gravitationally bound and that were born at the same time, with a given chemical composition.
How to view the 3-D image:
The pair of images above represents a star field of about 6 by 6 degrees. To see the cluster in three dimensions use the following "fused, free-eye imaging" method. View the screen from a distance of about 30-50 cm. Focus on the images, but relax the eyes so that they converge at infinity (imagine that you are staring through the screen at a distant point, so that the left eye observes and focuses on the left image, while the right eye focuses on the right image). Fix on a particular object until the depth effect appears: when it does, the results are dramatic.
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