Copyright © Philip M. Parker, INSEAD. Terms of Use.
Definition: White Dwarf |
White DwarfNoun1. A faint star of enormous density. Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
| Domain | Definition |
Astronomy | A star that is the remnant core of a star that has completed fusion in its core. The sun will become a white dwarf. White dwarfs are typically composed primarily of carbon, have about the radius of the earth, and do not significantly evolve further. (references) |
Physics | A star that has exhausted most or all of its nuclear fuel and has collapsed to a very small size. Typically, a white dwarf has a radius equal to about 0.01 times that of the Sun, but it has a mass roughly equal to the Sun's. This gives a white dwarf a density about 1 million times that of water!. (references) |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
According the Hertzsprung-Russell diagram, a white dwarf is a non-main sequence star, supported by electron degeneracy. Some white dwarfs are blue, rather than white. Many white dwarfs are approximately the size of Earth.
A star like our Sun will become a white dwarf when it has exhausted its nuclear fuel. Near the end of its nuclear burning stage, such a star goes through a red giant phase and then expels most of its outer material (creating a planetary nebula) until only the hot (T > 100,000 K) core remains, which then settles down to become a young white dwarf.
A typical white dwarf is half as massive as the Sun, yet only slightly bigger than Earth. This makes white dwarfs one of the densest forms of matter, surpassed only by neutron stars. The higher the mass of the white dwarf, the smaller the size. There is an upper limit to the mass of a white dwarf, the Chandrasekhar limit (about 1.4 times the mass of the Sun), after which the pressure of the electrons is no longer able to balance gravity, and the star continues to contract, eventually forming a neutron star.
Despite this limit, most stars end their life as white dwarf, since they tend to eject most of their mass into space before the final collapse (often with spectacular results, see planetary nebula). It is thought that even stars 8 times as massive as the Sun will in the end die as white dwarfs.
White dwarf stars are extremely hot, hence the bright white light they emit. This heat is a remnant of that generated from the star's collapse, and is not being replenished (unless they accrete matter from other closeby stars), but since white dwarfs have an extremely small surface area from which to radiate this heat energy they remain hot for a long period of time.
Eventually a white dwarf will cool into a black dwarf. Black dwarfs are ambient temperature entities and radiate weakly in the radio spectrum, according to theory. However, the universe has not existed long enough for any white dwarfs to have had enough time to cool down this far yet and so no black dwarfs are thought to exist.Many nearby, young white dwarfs have been detected as sources of soft X-rays (i.e. lower-energy X-rays); soft X-ray and extreme ultraviolet observations enable astronomers to study the composition and structure of the thin atmospheres of these stars.
White dwarfs cannot be over 1.4 solar masses, the Chandrasekhar limit, but there is a working method to get them over this limit. Touching on a nova, a white dwarf can accrete material from a companion. Unlike a nova, the material accretes slowly and remains stable. The mass of the white dwarf increases until it hits the 1.4 solar mass limit, at which degeneracy pressure cannot support the star. This is a type I supernova and is the most powerful of all the supernovae.
See also: brown dwarf, timeline of white dwarfs, neutron stars, and supernovae
White Dwarf is also the name of a magazine.
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "White dwarf."
(From Wikipedia, the free Encyclopedia)
White Dwarf is a magazine published by United Kingdom games manufacturer Games Workshop. Initially dedicated to all kinds of role-playing games the magazine is now dedicated just to those games produced by Games Workshop.Steve Jackson and Ian Livingstone produced a magazine called "Owl and Weasel" which ran for approximately 25 issues before being re-vamped into "White Dwarf."
First published in the 1970s and focused on wargaming, it received a strong boost when the first editions of the RPG Dungeons & Dragons, published in the UK by Games Workshop, referred to White Dwarf on its back page. This allowed people who had bought this game order the magazine directly from Games Workshop, establishing its circulation.
The magazine was hugely influential in the 1980s when it helped to popularise RPGs, including those American RPGs for which Games workshop had the UK licence. In addition to this a generation of writers passed through it offices and onto other RPG projects in the next decade, such as Phil Masters and Marcus Rowland.
The magazine has featured numerous articles and photographs about miniature figure painting.
Almost all British gamers have read White Dwarf, nicknamed by some as "Waste Drain", regularly at some point in their lives and pretty much all of them have an opinion as to when White Dwarf was "good". These periods are usually pre-issue 100 and often cluster around the issue 40 - 60 mark without any consensus ever being gained. Few are happy with the current incarnation, which is often little more than a house catalog.
For UK role-players the current successor to White Dwarf is Valkyrie and there are hopes that this magazine will replace the hole left in the hobby by this well-remembered magazine.
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "White Dwarf magazine."
Synonym: White DwarfSynonym: white dwarf star (n). (additional references) |
Crosswords: White Dwarf |
| Specialty definitions using "white dwarf": binary stars. (references) |
| Domain | Usage | |
Movie/TV Titles | White Dwarf (1995) | |
Source: compiled by the editor from various references; see credits. | ||
| Domain | Title |
Books | |
Periodicals |
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Source: compiled by the editor from various references; see credits. | |
| Thumbnail | Description & Credit |  | This artist's illustration shows three steps in the merger of a pair white dwarf stars. The ... Credit: NASA. |
Source: pictures compiled by the editor from various references; see picture credits. | |||
Expression using "white dwarf": white dwarf star. Additional references. | |
| Source: compiled by the editor from various references; see credits. |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Expression | Frequency per Day |
white dwarf | 95 |
white dwarf magazine | 15 |
white dwarf star | 12 |
snow white dwarf | 11 |
russian winter white dwarf hamster | 5 |
| Source: compiled by the editor from various references; see credits. | |
| Language | Translations for "white dwarf"; alternative meanings/domain in parentheses. | |
Bulgarian | малка звезда с голяма плътност. (various references) | |
Chinese | 白矮星 . (various references) | |
Danish | hvid dværg. (various references) | |
French | naine blanche. (various references) | |
German | weisser Zwerg. (various references) | |
Greek | άσπρος νάνος, λευκός νάνος. (various references) | |
Pig Latin | itewhay arfdway.(various references) | |
Portuguese | estrela anã branca. (various references) | |
Spanish | estrella enana blanca. (various references) | |
| Source: compiled by the editor from various translation references. | ||
Misspellings | |
"White Dwarf" is suggested in spellcheckers for the following: white drawf, white warf. (additional references) | |
| Source: compiled by the editor, based on several corpora (additional references). | |
Scrabble® Enable2K-Verified Anagrams | |
| Words within the letters "a-d-e-f-h-i-r-t-w-w" | |
-2 letters: withdraw, withdrew. | |
-3 letters: airthed, faithed, rawhide, thrawed, wharfed, wrathed, writhed. | |
-4 letters: adrift, airted, dafter, dawtie, dearth, dither, faired, father, hafted, hafter, haired, hatred, rafted, rifted, thawed, thawer, thread, tirade, trefah, wafted, wafter, waifed, waired, waited, waiter, warted, whited, whiter, withed, wither, wraith, wreath, writhe. | |
-5 letters: afire, afrit, after, aider, aired, airth, dater, deair, death. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
| 1. Definition 2. Synonyms 3. Crosswords 4. Usage: Modern | 5. Usage: Commercial 6. Images: Slideshow 7. Images: Photo Album 8. Expressions | 9. Expressions: Internet 10. Translations: Modern 11. Derivations 12. Anagrams | 13. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
