
	Where results make sense

Topic: Dwarf star

Related Topics

Red dwarf star

Stellar evolution

Brown dwarf

Astronomical object

Black dwarf

Vuosaari

Boise River

IBM 1403

Iscariot

Raguse

Petanque

Dntel

List of space disasters

R2I

Aes Sidhe

In the News (Thu 16 Feb 12)

EXECUTIVE POWER

Iran

ANALYSIS

Pakistan

Family compact

	Ask an Astronomer + Frequently Asked Questions
		In stars like the Sun, the inward pull of gravity is balanced by the outward push of the high-temperature hydrogen in the center fusing into helium and releasing energy in the process.
		Astronomers distinguish white dwarfs from other stars in two ways: (1) since they are faint stars, we can only see the nearby ones, and nearby stars appear to move relative to the background stars (2) they emit most of their light in the blue part of the spectrum.
		The exact process of a star becoming a white dwarf depends on the mass of the star, but all stars less massive than about 8 times the mass of the Sun (99% of all stars) will eventually become white dwarfs.
	www.whitedwarf.org /education/ask (819 words)

	StarsIntro
		A star is a body that at some time in its life generates its light and heat by nuclear reactions, specifically by the fusion of hydrogen into helium under conditions of enormous temperature and density.
		Stars can range up to about 100 times the mass of the Sun (at which point nature stops making them) down to around 8% that of the Sun, at which point the internal temperature is not high enough to run the full range of nuclear reactions (which requires at least 7 million degrees Kelvin).
		White dwarfs, the remains of stars that began their lives between 0.8 and 10 solar masses, no longer have any source of energy generation and are destined only to cool.
	www.astro.uiuc.edu /~kaler/sow/star_intro.html (5419 words)

	The Astrophysics Spectator: Degenerate Dwarf Stars
		The final evolutionary state for an intermediate-mass star is as a degenerate dwarf star, also called a white dwarf.
		It is this property that determines the characteristic radius of a degenerate dwarf star.
		red-giant phase, the progenitor is stripped of its atmosphere by its companion star.
	www.astrophysicsspectator.com /topics/stars/DegenerateDwarf.html (975 words)

	Different Types of Star
		It is a star with a diameter (width) less than half the diameter of the Sun, a surface temperature about 2000°c to 3000°c cooler.
		White Dwarfs are similar to Red Dwarfs, except that their surface temperatures are much higher, and shine white instead of red.
		These are stars that we cannot see, which have used up their energy for producing light, but are still closely-packed but still have a strong gravitational pull.
	members.aol.com /bobalien99/stardiff.htm (504 words)

	Brown Dwarfs (Site not responding. Last check: 2007-09-17)
		Originally called fl dwarfs (and often called enanas cafe in Mexico), these substellar objects were first conceived of in the early 1960s as dark bodies floating freely in space.
		Stellar models had suggested that a true star must have a m ass at least 80 times that of Jupiter to kindle the stable fusion of hydrogen.
		Brown dwarfs lack sufficient mass (about 80 Jupiters) to ignite the fusion of hydrogen in their cores, and thus never become true stars.
	astro.berkeley.edu /~stars/bdwarfs (228 words)

	Big Bertha Thing White Dwarfs, Neutron Stars, And Black Holes
		While a star is performing fusion reactions in its core, the outward pressure of the thermal motion of the particles in the star keeps it from collapse.
		The interior of a typical white dwarf is mostly composed of carbon and oxygen nuclei, though white dwarfs formed by smaller stars may be mostly helium and those formed by bigger stars may be formed of oxygen, neon, and magnesium.
		As already described, a white dwarf is the fossil remnant of a star that has exhausted its nuclear fuel, lost most of its mass in a planetary nebula, and cooled down to a dim cinder.
	www.geocities.com /tonylance/dwarf.html (6457 words)

	Interested in Dwarf star? Right place for it! Dwarf Star!
		The dwarf star majority of the Dwarfen strongholds have fallen, one by one, in the bitter wars with the Orcs and Goblins or Skaven, until now the remaining few Dwarf cities are under constant siege.
		In a few rare cases the companion star itself evolves into a neutron star, and dwarf woman the result is a binary neutron star system..
		The referee dwarf star failed to notice this, assumed that we are referring to a protostar according to his definition and then points out the problems that this would introduce.
	debtpop.sitesled.com /dwarf/star.html (2623 words)

	Life of a Star
		A whit dwarf star is a very small remnant of the original star, much cooler and very dim.
		As the star fades away, the electrons continue to collide to the nucleus of the atoms, causing the luminosity of the star to fade.
		Gravity at the core of the star continues to cause the electrons of atoms of the star to collide into their nucleuses.
	www.boscobel.k12.wi.us /~schnrich/life_of_a_star.htm (1452 words)

	White dwarf Summary
		As the white dwarf slowly cools, it ceases to shine and becomes a fl dwarf (not to be confused with a fl hole).
		Many white dwarfs are approximately the size of the Earth, typically 100 times smaller in diameter than the Sun; their average mass is about 0.5-0.6 solar masses, though there is quite a bit of variation.
		Black dwarfs are ambient temperature entities and radiate weakly in the radio spectrum, according to theory.
	www.bookrags.com /White_dwarf (2823 words)

	CNN.com - Object near sunlike star caught on camera - January 8, 2002
		The distance between the substellar object known as brown dwarf and its parent star is less than that between the planet Uranus and the sun.
		Brown dwarfs, middling objects between planets and stars, are considerably more massive than the largest planets but do not have enough mass to ignite the thermonuclear reactions necessary to become stars.
		In this composite image, light from the brighter primary star is removed from the region of the brown dwarf, lower left.
	archives.cnn.com /2002/TECH/space/01/07/brown.dwarf/index.html (525 words)

	Star Classification - Zoom Astronomy
		These stars will eventually explode (becoming a planetary nebula or supernova, depending on their mass) and then become white dwarfs, neutron stars, or fl holes (again depending on their mass).
		A brown dwarf is a "star" whose mass is too small to have nuclear fusion occur at its core (the temperature and pressure at its core are insufficient for fusion).
		X-ray binary stars are a special type of binary star in which one of the stars is a collapsed object such as a white dwarf, neutron star, or fl hole.
	www.enchantedlearning.com /subjects/astronomy/stars/startypes.shtml (1144 words)

	ESA Science & Technology: Astronomers use Hubble to 'weigh' Dog Star's companion [heic0516]
		For astronomers, it's always been a source of frustration that the nearest white-dwarf star is buried in the glow of the brightest star in the nighttime sky.
		White dwarfs are also the source of Type Ia supernova explosions that are used to measure cosmological distances and the expansion rate of the universe.
		Despite being the brightest white dwarf known, Sirius B is about 10 000 times fainter than Sirius itself, making it difficult to study with telescopes on the Earth's surface because its light is swamped in the glare of its brighter companion.
	hubble.esa.int /science-e/www/object/index.cfm?fobjectid=38420 (794 words)

	Text Only Homepage-Text
		A white dwarf is the final stage of the evolution of a star that is between.07 and 1.4 solar masses.
		White dwarf stars got their name because the first to be discovered had a white color.
		These stars are extremely dense because their large mass and small area White Dwarf stars are very dense.
	library.thinkquest.org /05aug/00108/textonlywhitedwarfcenter_frame.htm (520 words)

	Barnard's Star
		The star was named after its discoverer, noted astronomer Edward Emerson Barnard (1857-1923), who found in 1916 that the star has the largest known proper motion of all known stars (10.3 arcseconds per year).
		Its high space motion and sub-Solar metallicity suggests that the star is an intermediate Population II star," somewhere between a Halo and a disk star (Kürster et al, 2003; and John E.
		While the star may be as much as 11 or 12 billion years old (Ken Croswell, 2005), it may last another another 40 billion years or more before cooling into a fl dwarf.
	www.solstation.com /stars/barnards.htm (1317 words)

	MSSL Astrophysics Group - Stellar evolution (Site not responding. Last check: 2007-09-17)
		We have not yet observed a fl dwarf and it may be that the Galaxy is not old enough for any star to have had time to become a fl dwarf.
		If a white dwarf is orbiting around another star, a novae outburst can occur if they are close enough for material to get transfered from its companion.
		After the outburst, the white dwarf reverts to its previous state but eventually the process is repeated.
	www.mssl.ucl.ac.uk /www_astro/gal/stars/white.html (195 words)

	White Dwarfs and Electron Degeneracy
		When the triple-alpha process in a red giant star is complete, those evolving from stars less than 4 solar masses do not have enough energy to ignite the carbon fusion process.
		As the star contracts, all the lowest electron energy levels are filled and the electrons are forced into higher and higher energy levels, filling the lowest unoccupied energy levels.
		The star Sirius, referred to as Sirius-A, is perhaps most notable for the study of the "companion of Sirius" or Sirius-B which was the first example of a white dwarf star to be studied.
	hyperphysics.phy-astr.gsu.edu /hbase/astro/whdwar.html (758 words)

	Zoom Astronomy Glossary: B
		The brightest star in a constellation is alpha, the second-brightest is beta, the third is gamma, etc. Johannes Bayer (1564-1617) was a Bavarian (German) astronomer devised this system.
		The brightest star in Boötes is Arcturus, a red giant that is the fourth brightest star in the sky.
		A brown dwarf is a "star" whose mass is too small to have nuclear fusion occur at its core (the temperature and pressure at its core are insufficient for fusion) - a failed star.
	www.enchantedlearning.com /subjects/astronomy/glossary/indexb.shtml (2600 words)

	Scientific FrontLine / The Star, the Dwarf and the Planet
		This companion, a brown dwarf, is the faintest known companion of an exoplanet host star imaged directly and one of the faintest T dwarfs detected in the Solar neighborhood so far.
		In some cases, these stars were also found to have one or several stellar companions, showing that planet formation can also take place in a dynamically more complex environment than our own Solar System where planet formation occurred around an isolated single star.
		In two cases, however, the astronomers found the companions to be white dwarfs, that is, stars at the end of their life.
	www.sflorg.com /spacenews/sn101906_02.html (746 words)

	Brown Dwarfs (Site not responding. Last check: 2007-09-17)
		Originally called fl dwarfs (and often called enanas cafe in Mexico), these substellar objects were first conceived of in the early 1960s as dark bodies floating freely in space.
		Stellar models had suggested that a true star must have a m ass at least 80 times that of Jupiter to kindle the stable fusion of hydrogen.
		Brown dwarfs lack sufficient mass (about 80 Jupiters) to ignite the fusion of hydrogen in their cores, and thus never become true stars.
	astron.berkeley.edu /~stars/bdwarfs (228 words)

	White Dwarf
		White dwarfs are embers of dying stars shrunken to planetary dimensions.
		White dwarfs in close binary systems that feed hydrogen-rich matter from a main-sequence type star filling its Roche lobe, and then transfers the gas with the proper angular momentum to form an accretion disk that enshrouds the white dwarf.
		The inner region of the accretion disk onto a rotating magnetized central star (neutron star, white dwarf, or T Tauri star) is subjected to magnetic torques that induce warping and precession of the disk.
	business.fortunecity.com /rowling/167/SuperNovae/WhiteDwarf.html (1195 words)

	White Dwarfs - Introduction
		Where a star ends up at the end of its life depends on the mass it was born with.
		Stars that have a lot of mass may end their lives as fl holes or neutron stars.
		The white dwarf is surrounded by an expanding shell of gas in an object known as planetary nebula.
	imagine.gsfc.nasa.gov /docs/science/know_l1/dwarfs.html (1317 words)

	White Dwarfs and Novae
		Subrahmanyan Chandrasekhar predicted while a very young man in the 1930s that there was a limiting mass for white dwarf stars: no white dwarf could be stable against gravitational collapse if it exceeded this mass, which is about 1.4-1.5 solar masses, depending on the detailed composition of the white dwarf.
		Matter accretes in a thin layer on the surface of the white dwarf and eventually ignites in a thermonuclear explosion under degenerate conditions.
		The white dwarfs in the field are circled; as expected, they are quite faint compared with the other stars.
	csep10.phys.utk.edu /astr162/lect/novae/novae.html (415 words)

	red dwarf concept from the Astronomy knowledge base (Site not responding. Last check: 2007-09-17)
		Many red dwarfs are flare stars., A member of a class of dwarf stars (usually dM3e-dM6e) that show sudden, intense outbursts of energy.
		It is generally believed that flares in flare stars have certain properties in common: rapid rise to peak light followed initially by a rapid decline and later by a slower phase that occasionally does not return to a preflare level within practical monitoring times (several hours).
		During the quiescent phase the spectrum is that of an M dwarf with emissions in the CaII and Balmer lines.
	www.site.uottawa.ca:4321 /astronomy/reddwarf.html (443 words)

	Pulsating white dwarf star
		Being a white dwarf star, Kawaler said, BPM37093 has burned its nuclear fuel and all that remains is ash of carbon and oxygen.
		Crystallized white dwarf stars have been theorized to exist for 30 years, but because these stars are rare and exist under very extreme conditions, proving their existence has been a challenge.
		A pulsating white dwarf star that is snowing inside will be roughly 11 to 12 billion years old, rather than the currently estimated 9 billion years, Kawaler said.
	www.xs4all.nl /~carlkop/diamond.html (854 words)

	SPACE.com -- Star Search Finds Neighborly Red Dwarf
		The star, SO25300.5+165258, is a faint red dwarf star estimated to be about 7.8 light-years from Earth in the direction of the constellation Aries.
		Teegarden, the lead author of the study, and his colleagues happened upon the star while searching for nearby white dwarfs, the remains of collapsed stars that quickly traverse the night sky.
		Astronomers track white dwarfs like they track planets and near earth objects, by tracking their change in position over time.
	www.space.com /scienceastronomy/astronomy/red_dwarf_030520.html (516 words)

	ScienceDaily: FUSE Observations Strengthen White Dwarf Theory
		The FUSE result is important because Sirius B is one of the few stars that astronomers have to test their ideas on the relationship between mass and radius for white dwarf stars.
		Theory that describes how white dwarf stars can exist emerged in the early 1930s, when Subramanyan Chandrasekhar or Chandra, as he was known calculated the limit to a white dwarf's mass by applying Einstein's theory of special relativity.
		Unlike most white dwarfs, Sirius B is part of a binary system, and astronomers can determine the mass of stars in a binary system.
	www.sciencedaily.com /releases/2005/01/050125084745.htm (1089 words)

	StarDate Online \| Beyond the Solar System \| Stars \| Colorful Dwarfs
		The characteristic that distinguishes a giant star from a dwarf star is size, which depends on the star's mass and its stage in life.
		M dwarfs recently lost their title as the coolest stars, though, with the discovery of L dwarfs, a class of cool, dim objects that barely qualify as stars.
		Because their masses are so low, the core pressure in red-dwarf stars is low, so the stars are cool, red, and last a long, long time -- perhaps a trillion years or longer, compared to about 10 billion years for a star like the Sun.
	stardate.org /resources/btss/stars/colorful_dwarfs.php (655 words)

	08.16.00 - Brown dwarf star takes astronomers by surprise
		The unexpected observation of a bright flare on a nearby brown dwarf has shown astronomers that failed and fading stars like this still have some life left in them.
		Brown dwarfs are failed stars somewhere in mass between a large planet and a small star.
		The brown dwarf known as LP 944-20 is one of the nearest, only 16 light years from Earth.
	www.berkeley.edu /news/berkeleyan/2000/08/16/browndwarf.html (666 words)

	USATODAY.com - Brown dwarf found orbiting star like the sun (Site not responding. Last check: 2007-09-17)
		WASHINGTON – Discovery of a dwarf star orbiting close to a nearby sunlike star demonstrates that solar systems come in all shapes and sizes, astronomers say.
		Discovered orbiting the star 15 Sge, in the constellation Sagittarius, the brown dwarf star weighs in at about 65 times the mass of Jupiter, the largest planet in our solar system, says Michael Liu of the University of Hawaii, a member of the discovery team.
		Unlike the giant planets discovered by measuring gravitational tugs on their companion stars, the brown dwarf emerged through direct images of the star taken with a telescope armed with adaptive optics.
	www.usatoday.com /news/science/astro/2002-01-07-brown-dwarf.htm (492 words)

Try your search on: Qwika (all wikis)