
	Where results make sense

Topic: Protoplanet

Related Topics

Planetesimal

Proplyd

Accretion disc

Element

Protoplanetary disc

John Huarte

In the News (Wed 25 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Protoplanet - Open Encyclopedia (Site not responding. Last check: 2007-10-18)
		Such objects are formed by the accretion of objects (such as dust and planetesimals) within the accretion disc of a solar nebula.
		Early protoplanets are generally relatively hot and liquid.
		As the protoplanets cool into planets, their heavier elements will sink to the center; while lighter elements rise to the surface; such a process is known as planetary differentiation.
	open-encyclopedia.com /Protoplanet (89 words)

	Protoplanet - Wikipedia, the free encyclopedia
		In cosmogony, a protoplanet is a quasi-planetoid which is slightly larger than a planetesimal and orbits within a solar nebula's protoplanetary discs.
		Early protoplanets had more radioactive elements, the quantity of which has been reduced over time due to radioactive decay.
		In melted zones their heavier elements sank to the center; while lighter elements rose to the surface; such a process is known as planetary differentiation.
	en.wikipedia.org /wiki/Protoplanet (144 words)

	Protoplanet -- Facts, Info, and Encyclopedia article (Site not responding. Last check: 2007-10-18)
		Early protoplanets had more (Click link for more info and facts about radioactive) radioactive elements, the quantity of which has been reduced over time due to (The spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation) radioactive decay.
		Heating due to radioactivity, impact, and gravitational pressure melted parts of protoplanets as they grew toward being (Any of the celestial bodies (other than comets or satellites) that revolve around the sun in the solar system) planets.
		In melted zones their heavier (One of four substances thought in ancient and medieval cosmology to constitute the physical universe) elements sank to the center; while lighter elements rose to the surface; such a process is known as (Click link for more info and facts about planetary differentiation) planetary differentiation.
	www.absoluteastronomy.com /encyclopedia/p/pr/protoplanet.htm (158 words)

	eSky: Protoplanet (Site not responding. Last check: 2007-10-18)
		The initial phase in the development of a planet.
		A protoplanet is formed by the coalescence of material under the influence of gravity, a process referred to as accretion.
		As this accretion causes the mass of the protoplanet to increase, this in turn causes it to exert greater gravitational force on the matter around it, accelerating its development until it ultimately forms a true planet.
	www.glyphweb.com /esky/concepts/protoplanet.html (65 words)

	A Candidate Protoplanet in the Taurus Molecular Cloud (Site not responding. Last check: 2007-10-18)
		A Candidate Protoplanet in the Taurus Molecular Cloud
		NICMOS images made with the Hubble Space Telescope show what appears to be a giant protoplanet which has been ejected from the vicinity of a protostar.
		The bright filament, which appears to connect the protobinary and candidate protoplanet, may be an illumination channel through the dusty envelope/disk, created by the the object's passage.
	www.aas.org /publications/baas/v30n2/aas192/abs/S079004.html (282 words)

	Protoplanet (Universe)
		Constructs a new seed protoplanet at a random location within the specified range.
		Verifies that the protoplanet mass is non-zero and also different from the injected seed size.
		The limit depends on orbital eccentricity of the protoplanet and the shape of the initial cloud as well as the mass.
	universe.sourceforge.net /javadoc/org/gjt/universe/accrete/Protoplanet.html (583 words)

	IAU Symposium 202 - Poster paper (Site not responding. Last check: 2007-10-18)
		Protoplanets (runaway planetesimals) form as a result of runaway growth.
		The growth mode of protoplanets is called ``oligarchic growth''.
		In the oligarchic growth stage, protoplanets grow in the orderly mode keeping a certain orbital separation by orbital repulsion, while most planetesimals remain small.
	ast.star.rl.ac.uk /symp202/posters/late/kokubo.html (95 words)

	Protoplanet (Site not responding. Last check: 2007-10-18)
		En cosmogonías, un protoplanet es un quasi-planetoid que es ligeramente más grande que planetesimal y se mueve en órbita alrededor dentro de los discos protoplanetary de una nebulosa solar.
		Los protoplanets tempranos son generalmente relativamente calientes y líquidos.
		Como los protoplanets refrescarse en los planetas, sus elementos más pesados se hundirá al centro; mientras que son pálidos los elementos se levantan a la superficie; tal proceso se conoce como diferenciación planetaria.
	www.yotor.net /wiki/es/pr/Protoplanet.htm (114 words)

	IAU Symposium 202 - Poster paper (Site not responding. Last check: 2007-10-18)
		We present a mechanism related to the migration of giant protoplanets embedded in a protoplanetary disc whereby a giant protoplanet is caught up, before having migrated all the way to the central star, by a lighter outer giant protoplanet.
		This outer protoplanet gets captured into the 2:3 resonance with the more massive one, and the gaps that the two planets open in the disc overlap.
		Indeed under the conditions presented here, which describe the evolution of a pair of protoplanets respectively Jupiter and Saturn sized, the migration is reversed, while the planets semi-major axis ratio is constant and the eccentricities are confined to small values by the disc material.
	astro1.bnsc.rl.ac.uk /symp202/posters/late/masset.html (189 words)

	Spaceflight Now \| Breaking News \| Suspected protoplanet may really be a distant star
		This NASA Hubble Telescope near-infrared image of newborn binary stars reveals a long thin nebula pointing toward a faint companion object which was originally thought to be the first extrasolar planet to be imaged directly.
		In 1998, astronomer Susan Terebey of the Extrasolar Research Corp., Pasadena, CA, reported her observation at a scientific meeting as a possible young and hot "protoplanet" several times the mass of Jupiter.
		Because of its potential importance and the compelling nature of the image, NASA also released the picture to the public with the caution that future observations would be critical in verifying whether or not this object actually is a planet.
	spaceflightnow.com /news/n0004/07protoplanet/index.html (720 words)

	Gravitational Interaction between a Protoplanet and a Protoplanetary Disk: I. Local Three-Dimensional Simulations ... (Site not responding. Last check: 2007-10-18)
		Abstract: The gravitational interaction between a protoplanet and an isothermal gaseous disk is investigated through the three-dimensional hydrodynamical simulations with the shearing sheet model.
		The torque exerted on the disk is evaluated and compared with the previous estimates by the linear theory.
		Thus, the motion of the gas in the disk with thickness is similar to that in an infinitesimally thin disk.
	citeseer.ist.psu.edu /139133.html (203 words)

	[46.17] A Model of a Passive Accretion Disk Perturbed by a Protoplanet (Site not responding. Last check: 2007-10-18)
		While a large protoplanet whose Hill radius is larger than the disk scale-height will open a gap in on short timescales, the effect of a smaller protoplanet is subtler.
		The size of the perturbation depends on the mass of the protoplanet.
		It appears that the detailed three-dimensional and thermal structure of the disk in the vicinity of a protoplanet may have profound consequences for dust settling, gap formation, migration, and planet growth.
	www.aas.org /publications/baas/v34n4/aas201/820.htm (200 words)

	protoplanet -- Encyclopædia Britannica
		As the central body, or protostar, of the system contracts and heats up, the increasing pressure of its radiation is believed to drive off much of the thinner material of the protoplanets, particularly those closer to...
		For scientific theories on the unsolved problem of the origin of the solar system, see planetesimal; protoplanet; solar nebula.
		For an outline of the development of astronomical ideas regarding the structure of the universe, see cosmology; for theories on the...
	secure.britannica.com /eb/article-9061629 (563 words)

	Uses of Class org.gjt.universe.accrete.Protoplanet (Universe)
		Determines whether dust is present within the effect radius of a specific Protoplanet.
		Accretes dust and/or gas from all bands onto the specified protoplanet, iterating until the marginal mass increase approaches zero.
		Calculate the amount of dust which the specified protoplanet can accrete from this dust band, if any.
	universe.sourceforge.net /javadoc/org/gjt/universe/accrete/class-use/Protoplanet.html (95 words)

	A protoplanet the size of Mars smashes into Earth. (Site not responding. Last check: 2007-10-18)
		A protoplanet the size of Mars smashes into Earth.
		A protoplanet the size of Mars smashes into Earth, ejecting debris into space.
		As most of the Earth's iron had already sunk to its core, only enough iron was blasted into space to eventually make up the iron core of the moon--about 2% of her total mass.
	www.axelandalice.com /qhbc/04-450-000-000.html (69 words)

	DSpace at the Harvard University Physics Department: Item 123456789/19 (Site not responding. Last check: 2007-10-18)
		I present a method for calculating radiative transfer on a protoplanetary disk perturbed by a protoplanet and examine some of the ramifications of the resulting temperature variations.
		The gravitational potential of a protoplanet compresses the disk material around it, so that the disk's surface takes on the shape of a well.
		When such a well is illuminated by stellar irradiation at grazing incidence, it results in cooling in a shadowed region and heating in an exposed region.
	library.physics.harvard.edu /dspace/handle/123456789/19 (231 words)

	IngentaConnect Protoplanet Migration by Nebula Tides (Site not responding. Last check: 2007-10-18)
		The tidal interaction of a protoplanet with a circumstellar gaseous disk results in mutual angular momentum exchange that modifies both the disk and the orbit of the secondary.
		In this case, the protoplanet drifts relative to disk material on a time scale inversely proportional to its mass.
		A density discontinuity that locks the protoplanet into the disk's viscous evolution develops across the orbit.
	www.ingentaconnect.com /content/ap/is/1997/00000126/00000002/art05647 (326 words)

	Learn more about Protoplanet in the online encyclopedia. (Site not responding. Last check: 2007-10-18)
		Learn more about Protoplanet in the online encyclopedia.
		Enter a phrase or search word in the box below.
		Hint: Play with putting spaces before and after your words to see the different results you get.
	www.onlineencyclopedia.org /p/pr/protoplanet.html (170 words)

	SPACE.com -- Possible Planet Birth Detected in Chemistry Around Star
		In 1999, the Hubble telescope found gaps in a disk of material around HD 141569, hinting at possible planets in the far outer reaches of the disk.
		This speculative illustration shows where the gaseous protoplanet might exist (inner blue blob) around the star HD 141569.
		Researchers have known for a few years that the star, called HD 141569, has a disk of gas and dust surrounding it.
	www.space.com /scienceastronomy/astronomy/planet_birth_020703.html (762 words)

	AllRefer.com - protoplanet theory (Astronomy, General) - Encyclopedia
		AllRefer.com - protoplanet theory (Astronomy, General) - Encyclopedia
		You are here : AllRefer.com > Reference > Encyclopedia > Astronomy, General > protoplanet theory
		More articles from AllRefer Reference on protoplanet theory
	reference.allrefer.com /encyclopedia/X/X-protplnt.html (119 words)

	BIOASTRO Mailing List: SETI bioastro: Suspected Protoplanet May
		SETI bioastro: Suspected Protoplanet May Really Be A Distant Star
		protoplanet interpretation and the results remain consistent with
		This archive was generated by hypermail 2b30 : Wed Mar 28 2001 - 16:07:53 PST
	seti.sentry.net /archive/bioastro/2000/0017.html (589 words)

	IngentaConnect Reversing type II migration: resonance trapping of a lighter gian... (Site not responding. Last check: 2007-10-18)
		This outer protoplanet may get captured into the 2:3 resonance with the more massive one, in which case the gaps that the two planets open in the disc overlap.
		Two effects arise, namely a squared mass-weighted torque imbalance and an increased mass flow through the overlapping gaps from the outer disc to the inner disc, which both play in favour of an outwards migration.
		Indeed, under the conditions presented here, which describe the evolution of a pair of protoplanets respectively Jupiter- and Saturn-sized, the migration is reversed, while the semimajor axis ratio of the planets is constant and the eccentricities are confined to small values by the disc material.
	www.ingentaconnect.com /content/bsc/mnr/2001/00000320/00000004/art04159 (260 words)

	Catalogo Articoli (Site not responding. Last check: 2007-10-18)
		This outer protoplanet may get captured into the 2:3 resonance with the more massive one, in which case the gap's that the two planetsopen in the disc overlap.
		Indeed, under the conditions presented here, which describethe evolution of a pair of protoplanets respectively Jupiter- and Saturn-sized, the migration is reversed, while the semimajor axis ratio of the planets is constant and the eccentricities are confined to small values by the disc material.
		The long-term behaviour of the system is briefly discussed, and could account for the high eccentricities observed for the extrasolar planets with semimajor axis a > 0.2 au.
	serials.cib.unibo.it /cgi-ser/start/it/spogli/df-s.tcl?prog_art=3672804&language=ITALIANO&view=articoli (309 words)

	University of Hertfordshire, Astronomy (Site not responding. Last check: 2007-10-18)
		In one theory, the disc develops gravitational instabilities, in the same way that the parent gas cloud fragmented and collapsed.
		These instabilities collapse under gravity, dragging material in with them and become protoplanets.
		They eventually finish collapsing and planets are formed as a result.
	www.herts.ac.uk /astro_ub/a37_ub.html (485 words)

	Planetary Formation: Modelling the Capture Theory for the Origin of Planetary Systems (Site not responding. Last check: 2007-10-18)
		In this new type of encounter, the whole of the approaching protostar is tidally drawn into a long thin filament, with properties such that it is Jeans critical, but within the Roche limit, at perihelion.
		As the filament leaves perihelion, its orbit takes it outside of the Roche limit, and it is able to fragment into several protoplanets, of which around a half are captured.
		The major computational achievement of this thesis is the development of a robust radiation transport algorithm, ``tree radiation''.
	www.droxley.freeserve.co.uk (273 words)

	HubbleSite - Suspected Protoplanet May Really Be a Distant Star - 4/6/2000 (Site not responding. Last check: 2007-10-18)
		HubbleSite - Suspected Protoplanet May Really Be a Distant Star - 4/6/2000
		Follow-up observations of an unusual object initially suspected to be the first directly detected planet outside our solar system have shown that the object is too hot to be a planet.
		Astronomers now believe it is more likely that the strange object is a background star whose light has been dimmed and reddened by interstellar dust, giving the illusion that it is in the vicinity of the double star system in which it was initially believed to have been a planet.
	oposite.stsci.edu /pubinfo/pr/2000/13/index.html (114 words)

	NIR Spectroscopy of the Candidate Protoplanet TMR-1C (ResearchIndex) (Site not responding. Last check: 2007-10-18)
		NIR Spectroscopy of the Candidate Protoplanet TMR-1C (ResearchIndex)
		In a previous paper we proposed the possibility of a population of runaway planets and brown dwarfs which formed via ejection from multiple star systems.
		Based on HST/NICMOS data we suggested TMR-1C as a candidate runaway protoplanet (Terebey et al.
	citeseer.ist.psu.edu /386809.html (173 words)

	SPACE.com -- New Era Dawns in Search for Other Worlds
		Apparent knots of dust eclipsed the light from a star called SU Aurigae for several days at a time.
		They are thought by Villanova University researchers to be the seeds of planets, called protoplanets.
		A belt of dust very near a star known as HD 113766A could harbor a developing Earth-like planet.
	www.space.com /scienceastronomy/astronomy/dusty_worlds_020123-1.html (627 words)

	STScI- PR00-13: Suspected Protoplanet May Really Be a Distant Star
		STScI- PR00-13: Suspected Protoplanet May Really Be a Distant Star
		EDITOR'S NOTE: The Hubble image of TMR-1C and the initial press release (from May 28, 1998) are available at:
		The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for NASA, under contract with the Goddard Space Flight Center, Greenbelt, MD. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA).
	www.isset.org /hubble2000/PR/2000/13/index.html (653 words)

Try your search on: Qwika (all wikis)