- Aristotle Onassis (Wikipedia)
Aristotle Socrates Onassis (/oʊˈnæsɪs/, US also /-ˈnɑː-/; Greek: Αριστοτέλης Ωνάσης, romanized: Aristotélis Onásis, pronounced [aristoˈtelis oˈnasis]; 20 January 1906 – 15 March 1975) was a Greek and Argentine business magnate. He amassed the world’s largest privately-owned shipping fleet and was one of the world’s richest and most famous men. He was married to Athina Mary Livanos, had a long-standing affair with opera singer Maria Callas and was married to American former First Lady Jacqueline Kennedy.
- Open cluster (Wikipedia)
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.