R136a1
Encyclopedia
R136a1 is a blue hypergiant
star
and the most massive star known. It is an estimated 265 solar masses. The star is also the most luminous at 8,700,000 times the luminosity
of the Sun
.
It is a member of R136, a super star cluster
near the center of the 30 Doradus complex (also known as the Tarantula Nebula
), in the Large Magellanic Cloud
. The mass of the star was determined by Paul Crowther et al. (2010).
, used European Southern Observatory
's Very Large Telescope
(VLT) in Chile
, as well as data from the Hubble Space Telescope
, to study two star cluster
s, NGC 3603
and R136a
. R136a was once thought to be a supermassive object with 1000–3000 solar masses. R136a's nature was resolved by holographic
speckle interferometry and found to be a dense star cluster. The team found several stars with surface temperatures exceeding 40,000- 56,000 K, more than seven times that of the Sun
, and which are several million times brighter. At least three of the stars weigh in at about 150 solar masses.
Stars between about 8 and 150 solar masses explode at the end of their lives as supernovae, leaving behind neutron star
s or black hole
s. Having established the existence of stars between 150 and 300 solar masses, astronomers suspect that such an enormous star will perish as a hypernova
, a stellar explosion with an energy
of over 100 supernovae (1046 joule
s). The star may also die prematurely long before its core could collapse naturally from lack of fuel as a "pair instability supernova". Hydrogen-fusing cores should create large numbers of electron
–positron
pairs, which drop the thermal pressure present within the star to the point a partial collapse occurs. If R136a1 underwent such an explosion it would fail to leave behind a black hole
and instead the dozen solar masses of iron within its core would be blown out into the interstellar medium
as a supernova remnant
.
Hypergiant
A hypergiant is a star with a tremendous mass and luminosity, showing signs of a very high rate of mass loss.-Characteristics:...
star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
and the most massive star known. It is an estimated 265 solar masses. The star is also the most luminous at 8,700,000 times the luminosity
Luminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...
of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
.
It is a member of R136, a super star cluster
Super star cluster
A super star cluster is a very large region that is thought to be the precursor of a globular cluster. They typically contain a very large number of young, massive stars that ionize a surrounding H II region, similar to our Milky Way's so-called "Ultra dense H II regions ". An SSC's H II region is...
near the center of the 30 Doradus complex (also known as the Tarantula Nebula
Tarantula Nebula
The Tarantula Nebula is an H II region in the Large Magellanic Cloud . It was originally thought to be a star, but in 1751 Nicolas Louis de Lacaille recognized its nebular nature....
), in the Large Magellanic Cloud
Large Magellanic Cloud
The Large Magellanic Cloud is a nearby irregular galaxy, and is a satellite of the Milky Way. At a distance of slightly less than 50 kiloparsecs , the LMC is the third closest galaxy to the Milky Way, with the Sagittarius Dwarf Spheroidal and Canis Major Dwarf Galaxy lying closer to the center...
. The mass of the star was determined by Paul Crowther et al. (2010).
Discovery
News of the star's discovery was published in July 2010. A team of British astronomers led by Paul Crowther, professor of astrophysics at the University of SheffieldUniversity of Sheffield
The University of Sheffield is a research university based in the city of Sheffield in South Yorkshire, England. It is one of the original 'red brick' universities and is a member of the Russell Group of leading research intensive universities...
, used European Southern Observatory
European Southern Observatory
The European Southern Observatory is an intergovernmental research organisation for astronomy, supported by fifteen countries...
's Very Large Telescope
Very Large Telescope
The Very Large Telescope is a telescope operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. The VLT consists of four individual telescopes, each with a primary mirror 8.2m across, which are generally used separately but can be used together to...
(VLT) in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, as well as data from the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
, to study two star cluster
Star cluster
Star clusters or star clouds are groups of stars. Two types of star clusters can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars which are gravitationally bound, while open clusters, more loosely clustered groups of stars, generally contain less than...
s, NGC 3603
NGC 3603
NGC 3603 is an open cluster of stars situated in the Carina spiral arm of the Milky Way around 20,000 light-years away from the Solar System....
and R136a
R136a
R136, formally known as RMC 136, is a super star cluster near the center of the 30 Doradus complex , in the Large Magellanic Cloud. It is a young star cluster, 1-2 million years old, of giant and supergiant stars. The majority of its stars are of spectral type O3, with 39 confirmed O3-type stars...
. R136a was once thought to be a supermassive object with 1000–3000 solar masses. R136a's nature was resolved by holographic
Holographic interferometry
Holographic interferometry is a technique which enables static and dynamic displacements of objects with optically rough surfaces to be measured to optical interferometric precision . These measurements can be applied to stress, strain and vibration analysis, as well as to non-destructive testing...
speckle interferometry and found to be a dense star cluster. The team found several stars with surface temperatures exceeding 40,000- 56,000 K, more than seven times that of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, and which are several million times brighter. At least three of the stars weigh in at about 150 solar masses.
Physical characteristics
R136a1 is a Wolf–Rayet star with surface temperature over 50,000 K. Like other stars that are close to the Eddington limit, R136a1 has been shedding a large fraction of its initial mass through a continuous stellar wind. It is estimated that, at its birth, the star held 320 solar masses and has lost 50 solar masses over the past million years.Stars between about 8 and 150 solar masses explode at the end of their lives as supernovae, leaving behind neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
s or black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
s. Having established the existence of stars between 150 and 300 solar masses, astronomers suspect that such an enormous star will perish as a hypernova
Hypernova
Hypernova , also known as a type 1c Supernova, refers to an incredibly large star that collapses at the end of its lifespan...
, a stellar explosion with an energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
of over 100 supernovae (1046 joule
Joule
The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
s). The star may also die prematurely long before its core could collapse naturally from lack of fuel as a "pair instability supernova". Hydrogen-fusing cores should create large numbers of electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
–positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
pairs, which drop the thermal pressure present within the star to the point a partial collapse occurs. If R136a1 underwent such an explosion it would fail to leave behind a black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
and instead the dozen solar masses of iron within its core would be blown out into the interstellar medium
Interstellar medium
In astronomy, the interstellar medium is the matter that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, dust, and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space...
as a supernova remnant
Supernova remnant
A supernova remnant is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way.There are two...
.
See also
- List of most massive stars
- List of most luminous stars
- VY Canis MajorisVY Canis MajorisVY Canis Majoris is the largest known star and also one of the most luminous. Located in the constellation Canis Major, it is a red hypergiant, between 1800 and 2100 solar radii, 8.4–9.8 astronomical units in radius, about 3.0 billion km or 1.9 billion miles in diameter, and about 1.5 kiloparsecs ...
, the largest known star (as measured by solar radius) - Lynx ArcLynx ArcThe Lynx Arc was discovered in 2003 and is considered to be the hottest known star-birthing region in the Universe as of October 2003. It is located at ....