List of star extremes - AbsoluteAstronomy.com

List of star extremes

Encyclopedia

Distance

Title	Object	Date	Data	Comments	Notes	Refs	See more
Nearest star	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...	prehistoric (3rd century BCE)		Our local star's distance was first determined in the 3rd century BCE by Aristarchus of Samos Aristarchus of Samos Aristarchus, or more correctly Aristarchos , was a Greek astronomer and mathematician, born on the island of Samos, in Greece. He presented the first known heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe...	Reported for reference
Second nearest star	Proxima Centauri Proxima Centauri Proxima Centauri is a red dwarf star about 4.2 light-years distant in the constellation of Centaurus. It was discovered in 1915 by Robert Innes, the Director of the Union Observatory in South Africa, and is the nearest known star to the Sun, although it is too faint to be seen with the naked eye...	1915		Also called Alpha Centauri C, it is the outlying star in a trinary star system. This is currently the nearest known neighbouring star to our own Sun. This star was discovered in 1915, and its parallax was determined at the time, when enough observations were established.			List of nearest stars
Most distant star	Progenitor of GRB 090423 GRB 090423 GRB 090423 is a gamma-ray burst detected by the Swift Gamma-Ray Burst Mission on April 23, 2009 at 07:55:19 UTC. The afterglow of GRB 090423 was detected in the infrared, and allowed astronomers to determine that the redshift of GRB 090423 is z = 8.2, which makes GRB 090423 the second...	2009	z Redshift In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum... =8.2	The star (gamma ray burst progenitor) that caused this stellar explosion (gamma ray burst Gamma ray burst Gamma-ray bursts are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the most luminous electromagnetic events known to occur in the universe. Bursts can last from ten milliseconds to several minutes, although a typical... ) may have been destroyed in the process.

Nearest stars by type
Title	Object	Date	Data	Comments	Notes	Refs	See more
Nearest "average" star	Alpha Centauri Alpha Centauri Alpha Centauri is the brightest star in the southern constellation of Centaurus... A & B	1839	1.34 pc	This was the third star whose parallax was determined. Before Alpha Cen, the record was held by 61 Cygni 61 Cygni 61 Cygni,Not to be confused with 16 Cygni, a more distant system containing two G-type stars harboring the gas giant planet 16 Cygni Bb. sometimes called Bessel's Star or Piazzi's Flying Star, is a binary star system in the constellation Cygnus... , the first star whose parallax was determined.	An "average" star is a normal star which is larger than a red dwarf Red dwarf According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type.... , but smaller than a giant star Giant star A giant star is a star with substantially larger radius and luminosity than a main sequence star of the same surface temperature. Typically, giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Stars still more luminous than giants are... . Depending on the definition, this can also be called "Sun-like star".
Nearest normal star	Alpha Centauri C (Proxima Centauri Proxima Centauri Proxima Centauri is a red dwarf star about 4.2 light-years distant in the constellation of Centaurus. It was discovered in 1915 by Robert Innes, the Director of the Union Observatory in South Africa, and is the nearest known star to the Sun, although it is too faint to be seen with the naked eye... )	1915	1.3 pc	Before Proxima, the title had been held by Alpha Centauri A&B.
Nearest red dwarf Red dwarf According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....	Proxima Centauri Proxima Centauri Proxima Centauri is a red dwarf star about 4.2 light-years distant in the constellation of Centaurus. It was discovered in 1915 by Robert Innes, the Director of the Union Observatory in South Africa, and is the nearest known star to the Sun, although it is too faint to be seen with the naked eye...	1915	1.3 pc
Nearest degenerate star	Sirius B	1852	8.6 ly	This is also the nearest white dwarf	Not including stellar-mass black holes, or exotic star Exotic star An exotic star is a compact star composed of something other than electrons, protons, and neutrons balanced against gravitational collapse by degeneracy pressure or other quantum properties... s
Nearest 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...	RX J185635-3754	2000	200 ly
Nearest white dwarf White dwarf A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...	Sirius B	1852	8.6 ly	Sirius B is also the first white dwarf discovered.
Nearest flare star Flare star A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to magnetic reconnection in the atmospheres of the stars. The brightness increase is...	Proxima Centauri Proxima Centauri Proxima Centauri is a red dwarf star about 4.2 light-years distant in the constellation of Centaurus. It was discovered in 1915 by Robert Innes, the Director of the Union Observatory in South Africa, and is the nearest known star to the Sun, although it is too faint to be seen with the naked eye... (Alpha Centauri C)		1.3 pc	α Cen C is also the nearest neighbouring star.
Nearest brown dwarf Brown dwarf Brown dwarfs are sub-stellar objects which are too low in mass to sustain hydrogen-1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no chemical differentiation by depth...	Epsilon Indi B ( a & b )	2003	12 ly	ε Ind B is also the nearest brown dwarf binary pair. It was initially discovered and later that year was found to be binary, with a cooler smaller brown dwarf companion.

Brightness and power

Title	Object	Date	Data	Comments	Notes	Refs	See more
Brightest star	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...	prehistoric			Reported for reference By visual magnitude (m)This is the appearance in the sky from Earth.
Brightest star	Sirius Sirius Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek: Seirios . The star has the Bayer designation Alpha Canis Majoris... (Alpha Canis Majoris)	prehistoric	m=−1.46		This does not include brightest stars due to outburstsOther than 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...		List of brightest stars
Brightest star in a transient event	Progenitor of SN 1006 SN 1006 SN 1006 was a supernova, widely seen on Earth beginning in the year 1006 AD; Earth was about 7,200 light-years away from the supernova. It was the brightest apparent magnitude stellar event in recorded history reaching an estimated -7.5 visual magnitude...	1006	m=−7.5	This was a supernova Supernova A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months... , and its 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... (SNR) is catalogued as PKS 1459-41
Dimmest star
Most luminous star	R136a1 R136a1 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....	2010			Luminosity here represents how bright a star is if all stars were equally far away, in visible light.		List of most luminous stars
Most luminous star in a transient event
Least luminous normal star
Most energetic star	R136a1 R136a1 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....	2010			Energetic here is the total electromagnetic energy emitted by a star in all wavelengths.
Most energetic star in a transient event
Least energetic normal star
Hottest normal star
Coolest normal star

Title	Object	Date	Data	Comments	Notes	Refs	See more
Hottest degenerate star
Hottest neutron star
Hottest white dwarf	KPD 0005+5106	2008	200000 K
Hottest PG 1159 star PG 1159 star A PG 1159 star, often also called a pre-degenerate, is a star with a hydrogen-deficient atmosphere which is in transition between being the central star of a planetary nebula and being a hot white dwarf... /GW Vir star	RX J2117+3412	1999	170000 K
Coolest brown dwarf	UGPS J0722−05	2010	520 K Kelvin The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...

Size and mass

Title	Object	Date	Data	Comments	Notes	Refs	See more
Largest apparent size star	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...	prehistoric		The apparent size of the Sun was first measured by Eratosthenes Eratosthenes Eratosthenes of Cyrene was a Greek mathematician, poet, athlete, geographer, astronomer, and music theorist.He was the first person to use the word "geography" and invented the discipline of geography as we understand it... in the 3rd Century BCE, who was the second person to measure the distance to the Sun. However, Thales of Miletus provided a measurement for the real size of the Sun in the 6th Century BCE, as the great circle of the Sun (the orbit of the Earth)	Reported for reference
Largest apparent size star	R Doradus R Doradus R Doradus is the name of a red giant Mira variable star in the far-southern constellation Dorado, although visually it appears more closely associated with the constellation Reticulum. Its distance from Earth is 204 ± 9 light-years...	1997	0.057"	This replaced Betelgeuse Betelgeuse Betelgeuse, also known by its Bayer designation Alpha Orionis , is the eighth brightest star in the night sky and second brightest star in the constellation of Orion, outshining its neighbour Rigel only rarely... as the largest, Betelgeuse having been the first star other than the Sun to have its apparent size measured.
Smallest apparent size star
Most voluminous star	VY Canis Majoris VY Canis Majoris VY 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 ...						List of largest stars
Least voluminous normal star		2005	r=200000 kilometres (124,274.5 mi)		A normal star is a star that is past its protostar Protostar A protostar is a large mass that forms by contraction out of the gas of a giant molecular cloud in the interstellar medium. The protostellar phase is an early stage in the process of star formation. For a one solar-mass star it lasts about 100,000 years... period, in its main fusion period, before becoming a degenerate star, 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... , or post-stellar nebula, and is not a failed star (brown dwarf Brown dwarf Brown dwarfs are sub-stellar objects which are too low in mass to sustain hydrogen-1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no chemical differentiation by depth... ).
Most massive star	R136a1 R136a1 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....	2010	265 M_Sun Solar mass The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...	This exceeds the predicted limit of 150 solar mass Solar mass The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies... es, previously believed to be the limit of stellar mass, according to the leading star formation theories.	Not including stellar black hole Stellar black hole A stellar black hole is a black hole formed by the gravitational collapse of a massive star. They have masses ranging from about 3 to several tens of solar masses... s		List of most massive stars
Least massive normal star							List of least massive stars

Most massive stars by type
Title	Object	Date	Data	Comments	Notes	Refs	See more
Most massive brown dwarf	PPl 15	1996	80 M_Jupiter Jupiter mass Jupiter mass , is the unit of mass equal to the total mass of the planet Jupiter . Jupiter mass is used to describe masses of the gas giants, such as the outer planets and extrasolar planets. It is also used in describing brown dwarfs....	This is at the limit between brown dwarfs and red dwarfs.
Most massive degenerate star	The most massive type of degenerate star is the neutron star. See Most massive neutron star for this recordholder.
Most massive neutron star	PSR J1614−2230	2010	1.97 M_Sun	This millisecond pulsar Millisecond pulsar A millisecond pulsar is a pulsar with a rotational period in the range of about 1-10 milliseconds. Millisecond pulsars have been detected in the radio, X-ray, and gamma ray portions of the electromagnetic spectrum. The origin of millisecond pulsars is still unknown... greatly exceeds the predicted limit of neutron star size of roughly 1.5 solar masses. The previous titleholder only massed of 1.67 solar masses.
Most massive white dwarf	RE J0317-853	1998	1.35 M_Sun

Least massive stars by type
Title	Object	Date	Data	Comments	Notes	Refs	See more
Least massive brown dwarf							List of least massive stars
Least massive degenerate star	The least massive type of degenerate star is the white dwarf. See Least massive white dwarf for this recordholder.
Least massive neutron star
Least massive white dwarf	SDSS J091709.55+463821.8 (WD J0917+4638)	2007	0.17 M_Sun

Motion

Title	Object	Date	Data	Comments	Notes	Refs	See more
Highest proper motion Proper motion The proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...	Barnard's Star Barnard's star Barnard's Star, also known occasionally as Barnard's "Runaway" Star, is a very low-mass red dwarf star approximately six light-years away from Earth in the constellation of Ophiuchus . In 1916, the American astronomer E.E...		10.3 "/yr Year A year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic....	This is also the fourth closest star to Earth
Lowest proper motion Proper motion The proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...
Highest radial velocity Radial velocity Radial velocity is the velocity of an object in the direction of the line of sight . In astronomy, radial velocity most commonly refers to the spectroscopic radial velocity...
Lowest radial velocity Radial velocity Radial velocity is the velocity of an object in the direction of the line of sight . In astronomy, radial velocity most commonly refers to the spectroscopic radial velocity...
Highest peculiar motion
Lowest peculiar motion
Highest rotational speed Rotational speed Rotational speed tells how many complete rotations there are per time unit. It is therefore a cyclic frequency, measured in hertz in the SI System... of a normal star
Lowest rotational speed Rotational speed Rotational speed tells how many complete rotations there are per time unit. It is therefore a cyclic frequency, measured in hertz in the SI System...

Star systems

Title	Object	Date	Data	Comments	Notes	Refs	See more
Least stars in a star system	There are many stars in single star systems
Most stars in a star system Star system A star system or stellar system is a small number of stars which orbit each other, bound by gravitational attraction. A large number of stars bound by gravitation is generally called a star cluster or galaxy, although, broadly speaking, they are also star systems.-Binary star systems:A stellar...	Nu Scorpii Nu Scorpii Nu Scorpii is a star system in the constellation Scorpius.It is at least a quintuple star, probably a septuple, consisting of two close groups that are separated by 41". The brighter group, Nu Scorpii A and B, is split by 1.3" and composed of spectral type B2 subgiants... AR Cassiopeiae AR Cassiopeiae AR Cassiopeiae is a multiple star system in the constellation of Cassiopeia. It is thought to be a septuple star system. It is only one of two star systems with a multiplicity of 7, the other being Nu Scorpii, with no physical multiple stars of greater multiplicity yet found.The star was...		Septuple star system	Both are called 7-star systems in the 1997 MSC, and appear in the 2008 MSC.	The allowable distance between components of a star system is debated.
Stars in the closest orbit around one another	There are many stars that are contact binaries, where the stars are in physical contact with each other
Stars in the most distant orbit around one another
Nearest multiple star system	Alpha Centauri Alpha Centauri Alpha Centauri is the brightest star in the southern constellation of Centaurus...	1839	1.3 pc	This was one of the first three stars to have its distance measured.

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