- An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and many more are thought to exist. Each one is loosely bound by mutual gravitational attraction and becomes disrupted by close encounters with other clusters and clouds of gas as they orbit the Galactic Center. This can result in a loss of cluster members through internal close encounters and a dispersion into the main body of the galaxy. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral and irregular galaxies, in which active star formation is occurring.
- Helix (newspaper) (Wikipedia)
The Helix was an American biweekly newspaper founded in 1967 after a series of organizational meetings held at the Free University of Seattle involving a large and eclectic group including Paul Dorpat, Tom Robbins, Ray Collins, and Lorenzo Milam. A member of both the Underground Press Syndicate and the Liberation News Service, it published a total of 125 issues (sometimes as a weekly, sometimes as a biweekly) before folding on June 11, 1970.