The Sun vs. hypergiant with dust disc in LMC

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. Hypergiants are not necessarily larger than supergiants, but are usually more massive. 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 supernova or possibly hypernova. It is theorised that a hypergiant gone supernova or hypernova will leave a remnant black hole. Image File history File linksMetadata Download high resolution version (3000x2400, 1744 KB) Summary Source: Primary Image Credit: NASA/JPL-Caltech Image produced by: R. Hurt (SSC) Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File linksMetadata Download high resolution version (3000x2400, 1744 KB) Summary Source: Primary Image Credit: NASA/JPL-Caltech Image produced by: R. Hurt (SSC) Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The Sun is the star at the center of the Solar System. ... The Large Magellanic Cloud (LMC for short) is a dwarf galaxy that orbits our own galaxy, the Milky Way. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... STAR is an acronym for: Organizations Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... In most modern usages of the word spectrum, there is a unifying theme of between extremes at either end. ... Photo taken during the French 1999 eclipse The stellar atmosphere is the outer region of the volume of a star, lying above the stellar core, radiation zone and convection zone. ... Supergiants are the most massive stars. ... Unsolved problems in physics: What causes anything to have mass? The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. Mass is the property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... The Sun is the star at the center of the Solar System. ... Supergiants are the most massive stars. ... Eddington luminosity (sometimes also called the Eddington limit) is the largest luminosity that can pass through a layer of gas in hydrostatic equilibrium, supposing spherical symmetry. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... Solar irradiance spectrum at top of atmosphere. ... Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. ... In astronomy, stellar evolution is the sequence of radical changes that a star undergoes during its lifetime (the time in which it emits light and heat). ... The solar luminosity, , is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ... Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ... Eta Carinae, in the constellation of Carina, one of the nearer candidates for a hypernova Hypernova (pl. ... This article or section is in need of attention from an expert on the subject. ...

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. It has been suggested that Andromeda-Milky Way collision be merged into this article or section. ... The two Magellanic Clouds are irregular dwarf galaxies that may be orbiting our Milky Way galaxy[1], and thus are members of our Local Group of galaxies. ...

To see what a hypergiant might look like compared to the Sun, refer to this link: ^[1].

Known hypergiants

Luminous blue variables

The most massive luminous blue variables are classified as hypergiants, and indeed they are the most luminous stars known: Also known as S Doradus type stars, a luminous blue variable is a very large, very bright, variable star. ...

• P Cygni, in the northern constellation of Cygnus.
• S Doradus, in a nearby galaxy called the Large Magellanic Cloud, in the southern constellation of Dorado. This galaxy was also the location of Supernova 1987A.
• Eta Carinae, inside the Keyhole Nebula (NGC 3372) in the southern constellation of Carina. Eta Carinae is extremely massive, possibly as much as 120 to 150 times the mass of the Sun, and is four to five million times as luminous.
• The Pistol Star, near the center of the Milky Way, in the constellation of Sagittarius. The Pistol Star is possibly as much as 150 times more massive than the Sun, and is about 1.7 million times more luminous.
• Several stars in the cluster 1806-20, on the other side of the Milky Way galaxy. One such star, LBV 1806-20, is the most luminous star, from 2 to 40 million times as luminous as the Sun, and also one of the most massive.

P Cygni is itself slowly a star variable in the brightness in the constellation swan. ... Cygnus (IPA: , Latin: ) is a northern constellation. ... S Doradus is the brightest star in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 17,000 parsecs in diameter and approximately 20 million parsecs distant. ... The Large Magellanic Cloud (LMC for short) is a dwarf galaxy that orbits our own galaxy, the Milky Way. ... Other uses: dorado is used in the fisheries of some Latin American countries to denote the edible fish mahi-mahi (Coryphaena hippurus Dorado is also the name of mythical Latin American warriors. ... 1987A supernova remnant near the center SN 1987A was a supernova in the Large Magellanic Cloud, a nearby dwarf galaxy. ... Eta Carinae (η Carinae or η Car) is a highly luminous hypergiant star. ... NGC 3372, the Eta Carinae Nebula. ... Carina (IPA: , Latin: ) is a southern constellation which forms part of the old constellation of Argo Navis. ... The Pistol Star, once thought to be the brightest star in the Milky Way galaxy (exceeded only by LBV-1806), is 10 million times as bright as the Sun and about 100 times as massive. ... For other uses, see Sagittarius. ... 1806-20 is an atypical cluster of large, high-luminosity stars. ... LBV 1806-20 is a possible binary star located 30,000–49,000 light years from our Sun, toward the center of the galaxy. ...

Yellow hypergiants

Yellow hypergiants form an extremely rare class of stars, with only seven being known in our galaxy: Generally speaking, a yellow hypergiant is a very massive star with an extended chromosphere, which can be classified under the system as a spectral Class G, with a mass of up to approximately 120 solar masses (believed to be the upper limit of stellar mass). ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 17,000 parsecs in diameter and approximately 20 million parsecs distant. ...

• Rho Cassiopeiae, in the northern constellation of Cassiopeia, is about 500,000 times as luminous as the Sun.
• HR 8752
• IRC+10420
• Also see stars in Westerlund 1.

Rho Cassiopeiae (ρ Cas / ρ Cassiopeiae) is a yellow hypergiant in the constellation Cassiopeia. ... Cassiopeia (IPA: ) is a northern constellation which Greek mythology considered to represent a vain queen who boasted about her unrivaled beauty. ... Westerlund 1 (sometimes WD1) is the most massive compact young star cluster in the local group. ...

Red hypergiants

• NML Cygni
• VX Sagittarii
• S Persei
• VY Canis Majoris is the largest known star , with a diameter from 1800 to 2100 times the size of the diameter of the Sun.

This is the largest star known on Earth Category: ...

See also

• Supergiants