- Hypergiant (Wikipedia)
A hypergiant (luminosity class 0, Ia-0 or Ia+) is a very rare type of star that has an extremely high luminosity, mass, size and mass loss because of its extreme stellar winds. The term hypergiant is defined as luminosity class 0 (zero) in the MKK system. However, this is rarely seen in literature or in published spectral classifications, except for specific well-defined groups such as the yellow hypergiants, RSG (red supergiants), or blue B(e) supergiants with emission spectra. More commonly, hypergiants are classed as Ia-0 or Ia+, but red supergiants are rarely assigned these spectral classifications. Astronomers are interested in these stars because they relate to understanding stellar evolution, especially star formation, stability, and their expected demise as supernovae. Notable examples of hypergiants include the Pistol Star, a blue hypergiant located close to the Galactic Center and one of the most luminous stars known; Rho Cassiopeiae, a yellow hypergiant that is one of the brightest to the naked eye; and Mu Cephei (Herschel’s “Garnet Star”), one of the largest and brightest stars known.
Stanford Encyclopedia of Philosophy
- Stoicism (plato.standford.edu)
Stoicism was one of the dominant philosophical systems of the Hellenistic period. The name derives from the porch (stoa poikilê) in the Agora at Athens decorated with mural paintings, where the first generation of Stoic philosophers congregated and lectured. The school of thought founded there long outlived the physical Athenian porch and notably enjoyed continued popularity in the Roman period and beyond. This entry introduces the main doctrines and arguments of the three parts of Stoic philosophy – physics, logic, and ethics – emphasizing their interlocking structure. We also review the history of the school, the extant sources for Stoic doctrine, and the Stoics’ subsequent philosophical influence.
- Stoicism (Wikipedia)
Stoicism is a school of Hellenistic philosophy that flourished in Ancient Greece and Ancient Rome. The Stoics believed that the practice of virtue is enough to achieve eudaimonia: a well-lived, flourishing life. The Stoics identified the path to achieving it with a life spent practicing certain virtues in everyday life such as courage or temperance and living in accordance with nature. It was founded in the ancient Agora of Athens by Zeno of Citium around 300 BC.