|
A hypergiant (luminosity class 0) is a massive star whose spectrum indicates the presence of an extended atmosphere. Hypergiants are at least as large as supergiants, having masses up to 100 times that of the Sun. This approaches the theoretical upper limit of star mass (about 120 solar masses), the point at which a star generates so much radiation that it throws off its outer layers. Some hypergiants appear to be more than 100 solar masses and may have initially been 200 to 250 solar masses, challenging current theories of star formation and evolution. Hypergiants are the most luminous stars, thousands to millions of times the solar luminosity; however, their temperatures vary widely between 3,500 K and 35,000 K. They have extremely short lives, lasting approximately 1 to 3 million years, before turning into supernovae or possibly hypernovae. It is theorised that a hypergiant gone supernova or hypernova will leave a remnant black hole. Hypergiants are difficult to study due to their rarity. Until recently, only 7 hypergiants were known in the Milky Way; several more are known in the Magellanic Clouds. Almost all hypergiants exhibit variations in luminosity over time due to instabilities in the stellar interior at moderate temperatures and high pressures. To see what a hypergiant might look like compared to the Sun, refer to this link: *.
Luminous blue variables The most massive luminous blue variables are classified as hypergiants, and indeed they are the most luminous stars known: Yellow hypergiants Yellow hypergiants form an extremely rare class of stars, with only seven being known in our galaxy: Red hypergiants See also | ||||||||
|
| |||||||||
 |
|
| |