- 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.
- Nikolai Patrushev (Wikipedia)
Nikolai Platonovich Patrushev (Russian: Никола́й Плато́нович Па́трушев; born 11 July 1951) is a Russian politician, security officer and former intelligence officer who served as the secretary of the Security Council of Russia from 2008 to 2024. He previously served as the director of the Federal Security Service (FSB) from 1999 to 2008. Belonging to the siloviki faction of president Vladimir Putin’s inner circle, Patrushev is believed to be one of the closest advisors to Putin and a leading figure behind Russia’s national security affairs. He played a key role in the decisions to seize and then annex Crimea in 2014 and to invade Ukraine in 2022.