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	Solar wind - Wikipedia, the free encyclopedia
		In the heliosphere, the composition of the solar wind is identical to the Sun's corona: By mass, 73% ionized hydrogen and 25% doubly ionized helium with the remainder as trace impurities.
		Outside the plane of the ecliptic the solar wind is steady and rapid, at speeds between 600-800 km/s; this is called the fast solar wind and it is known to emanate from solar coronal holes.
		The solar wind blows a "bubble" in the interstellar medium (the rarefied hydrogen and helium gas that permeates the galaxy).
	en.wikipedia.org /wiki/Stellar_wind (2132 words)

	The Solar Wind
		The first indication that the sun might be emitting a "wind" came from comet tails, observed to point away from the Sun, whether the comet was approaching the Sun or whether it was moving away.
		The distribution of ions in the solar wind generally resembles the distribution of elements on the Sun-- mostly protons, with 5% helium and smaller fractions of oxygen and other elements.
		It is the IMF that allows the solar wind to "pick up" the ions in a comet's ion tail, as it also did to an "artificial comet" produced in a 1985 experiment (see positive ions, "clouds of barium ions").
	www-spof.gsfc.nasa.gov /Education/wsolwind.html (819 words)

	Stellar Winds
		A key attribute of stellar winds is that they are continuous phenomena, as opposed to episodic outbursts.
		The particles comprising the winds are accelerated differently, depending upon the nature of the star.
		Their stellar winds thus remain at temperatures comparable to the star's surface, and so lack the very high gas-pressure needed to drive an outward expansion against the stellar gravity.
	www.peripatus.gen.nz /Astronomy/SteWin.html (1506 words)

	ScienceDaily: Scientists Track Collision Of Powerful Stellar Winds
		Mapping Orion's Winds (January 16, 2006) -- For the past few months, Bob O'Dell has been mapping the winds blowing in the Orion Nebula, the closest stellar nursery similar to the one in which the Sun was born.
		Stellar classification -- In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral...
		Stellar evolution -- In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime; the hundreds of thousands, millions or billions of years during which it emits light and heat.
	www.sciencedaily.com /releases/2005/04/050413095400.htm (1861 words)

	X-ray Emission from Colliding Stellar Winds
		Colliding stellar winds occur in a massive binary star system where each star has a powerful stellar wind (somewhat akin to the solar wind, but roughly a billion times more powerful!).
		An excellent "feel" for colliding stellar winds can be obtained from a movie of recent observations which spatially resolve the wind collision in WR 104.
		If the companion wind was weaker the shock arms would bend towards each other (the opening angle of the shock cone would decrease), and with limited spatial resolution a single spiral would be seen.
	www.ast.leeds.ac.uk /~jmp/New/csw.html (936 words)

	Winds that Sail on Starlight (Site not responding. Last check: 2007-10-01)
		These stars are so bright that their light propels stellar winds -- up to a billion times stronger than the solar wind -- at speeds up to one percent of the speed of light.
		In the case of winds from hot stars, the flood of light is so intense that the momentum of photons striking the atoms of gas drives a high-speed flow.
		In the three cases, the absorption of radiation by Wolf-Rayet wind material is 1.0, 2.0, and 5.0 times that of the companion star's wind, altering the effectiveness of radiative braking.
	www.sdsc.edu /GatherScatter/GSwinter97/owocki.html (1347 words)

	Orion Nebula shines in its grandest portrait - Space.com - MSNBC.com
		Similar to how winds on Earth can sculpt sand dunes in a desert, stellar winds from the Trapezium are carving out a cavity relatively free of dust and gas, filled with strange, ethereal scenes.
		If the winds are strong enough, their shock waves act as catalysts for star formation by pushing the clouds together into compact bundles.
		O'Dell used Hubble to map Orion's stellar winds with unprecedented detail; he discovered that the shock waves can have different shapes, depending on whether the dust and gas clouds were moving or stationary when the winds passed through.
	msnbc.msn.com /id/10806310 (798 words)

	Interstellar Gas Dynamics
		The dependence of the problem of the structure of the flow in the interaction region on the dimensionless parameters is studied, and a simple expression is derived for the size of the pre-heating zones at the axis of symmetry.
		Consideration of the development of the nebula shows that in the early stages it is the ionization of the aspherical AGB wind that contributes considerably to the shaping of the nebula.
		Furthermore, the passing through of the ionization front may modify the density distribution in the slow wind, leading to the formation of a surrounding envelope, and sometimes a different morphology for the nebula from that to be expected from the initial conditions.
	laserstars.org /references/winds/index.html (2257 words)

	Scientists Track Collision of Powerful Stellar Winds
		The supersharp radio "vision" of the continent-wide VLBA allowed the scientists to measure the motion of the wind collision region and then to determine the details of the stars' orbits and an accurate distance to the system.
		The scientists watched the changes in the stellar system as the star's orbits carried them in paths that bring them nearly as close to each other as Mars is to the Sun and as far as Neptune is from the Sun.
		At some points in the orbit, the wind collision region strongly emitted radio waves, and at other points, the scientists could not detect the collison region.
	www.nrao.edu /pr/2005/wr140 (623 words)

	Exploring News & Features - Mapping Orion’s winds (Site not responding. Last check: 2007-10-01)
		For the past few months, Bob O’Dell has been mapping the winds blowing in the Orion Nebula, the closest stellar nursery similar to the one in which the sun was born.
		When these stellar winds impact floating clouds of dust and gas, they produce shock waves that erode and shape the clouds in a fashion similar to the way in which terrestrial winds sculpt sand dunes.
		The specific objects that are producing these winds in the two regions are not visible to optical telescopes but they stand out as hot spots in infrared images.
	www.exploration.vanderbilt.edu /news/news_orionwinds.htm (777 words)

	STELLAR WINDS AND X-RAY EMISSION: RESOLVING THE CONNECTION WITH THE HRI
		We have organized an effort to address the question of how X-ray emission is related to stellar wind emission in hot young stars using a deep HRI pointing of the Carina nebula region along with coordinated ground-based observations.
		During this meeting, it became quite evident that, despite the enormous progress that X-ray studies have provided in revealing the dynamics of stellar winds from hot stars, none of the existing time series (normally isolated snapshots of some 10 ks) is long enough to adequately sample the dominant physical timescales in hot luminous stars.
		Colliding wind emission provides a direct, localized probe of the dependence of X-ray emission on wind mass-loss rate and the physics of wind acceleration by the line-driving mechanism.
	heasarc.gsfc.nasa.gov /docs/rosat/proc/corcor/corcor.html (1773 words)

	Introduction to Stellar Winds - Cambridge University Press
		This long-awaited graduate textbook, written by two pioneers of the field, is the first to provide a comprehensive introduction to the observations, theories and consequences of stellar winds.
		This authoritative textbook is designed for advanced undergraduate and graduate students and researchers seeking an understanding of stellar winds and, more generally, supersonic flows from astrophysical objects.
		It fills a long-standing gap in the astrophysical literature and will stand as the foundation of the rapidly growing field of stellar winds.' Professor Norbert Langer, University of Potsdam 'Stellar winds are ubiquitous, but their properties and mechanisms span an enormous range.
	www.cup.cam.ac.uk /catalogue/print.asp?isbn=0521595657&print=y (379 words)

	Colliding winds in binaries
		In fact, in a massive binary, the highly supersonic stellar winds collide and the plasma in the resulting shock zone is heated to temperatures of several ten million degrees, thereby generating an X-ray emission.
		Indeed, the systematic study of the X-ray emission produced in a colliding wind interaction offers the possibility to address several open questions that are relevant for a better understanding of massive stars and of their impact on the interstellar medium.
		One topic that can be addressed is the chemical composition of the stellar winds of WR stars, which are evolved massive stars displaying the products of nuclear burning at their surface.
	vela.astro.ulg.ac.be /themes/stellar/massive/coll_e.html (836 words)

	Stellar Weathervane :: Astrobiology Magazine ::
		Summary (Dec 02, 2005): A research team investigated a disk of gas and dust surrounding a young star, as well as the stellar winds which emanate from that star.
		The scientists used a new modelling method to evaluate the measured data, interpreting their observations of both the accretion disk and the stellar wind.
		Although the gas near the disk moves at an expansion velocity of only 60 kilometers per second, the stellar wind in the direction of the poles blows at up to 600 kilometers per second.
	www.astrobio.net /news/article1792.html (791 words)

	Stellar Winds and Galactic Superwinds
		On the smallest scales, hypersonic winds from massive stars in binary systems collide and generate X-ray emission from the very hot shocked gas.
		On larger scales, these winds interact with the local circumstellar or interstellar medium (ISM) to produce wind-blown bubbles (WBBs), and supernova ejecta interact with the local ISM or nuclear winds in the central regions of active galaxies.
		Further information on stellar winds and galactic superwinds can be found on the personal homepage of Dr.
	www.ast.leeds.ac.uk /research/winds.html (453 words)

	Accretion of Stellar Winds in the Galactic Centre
		Galactic Centre stellar winds and Sgr A* accretion
		Sgr A* is currently being fed by winds from a cluster of gravitationally bound young mass-losing stars.
		Since the stellar distribution is still known only roughly, we run a test with the same parameters, but with orbits oriented isotropically.
	www.mpa-garching.mpg.de /~jcuadra/Winds (800 words)

	Radiation driven winds of hot stars:
		They have enormous stellar winds which provide the surrounding interstellar medium with mechanical energy and momentum and recycled nuclear burned material.
		A modern numerical stellar wind code includes the contributions of some 140 of such ions with all their spectral lines and all occupation numbers calculated in non-LTE.
		Since the winds are driven by radiative acceleration in metal lines, effective temperature and the stellar metal abundance affect the WLR.
	www.ifa.hawaii.edu /users/kud/windsfromhotstars/winds.html (491 words)

	Solar & Stellar Winds Seminar (Site not responding. Last check: 2007-10-01)
		The goal is to develop a clear comprehensive picture of the current understanding of the solar wind, and identify those areas that require further research, either in theoretical concepts, numerical modelling, or observations.
		A further goal is to obtain an understanding of the applicability of the new results in solar wind research to stellar winds, and those from other objects.
		Chapter 2 in: "Introduction to Stellar Winds", by Henny Lamers and Joe Casinelli 1999, Cambridge University Press.
	solar.physics.montana.edu /martens/winds (445 words)

	APOD: 2001 October 19 - X-Ray Stars and Winds in the Rosette Nebula (Site not responding. Last check: 2007-10-01)
		swath across the photogenic Rosette Nebula, a stellar nursery 5,000 light-years from Earth in the constellation Monoceros, the Unicorn.
		Since these stars are so young (less than few million years old!) the diffuse x-ray emission is thought to be powered by energetic, colliding stellar winds rather than remnants of supernovae explosions, a final act in the life cycle of a massive star.
		Moving away from the center, south and east across the nebula (upper right to lower left), the hot, blustery environment gives way to dense molecular gas, absorbing low energy x-rays while revealing the penetrating high energy x-rays from embedded stars.
	antwrp.gsfc.nasa.gov /apod/ap011019.html (217 words)

	Science Journal -- Spring 2001 --X-Rays from Stellar Winds May Play Role in Galactic Evolution
		The red sources in the ACIS images are dominated by low-energy X-rays and suffer little absorption by the molecular cloud, while the blue sources are very young stars still embedded in the gas and dust from which they formed.
		A team led by Leisa Townsley, a senior research associate in astronomy and astrophysics at Penn State, uncovered this wind phenomenon in the Rosette Nebula, a stellar nursery.
		With the Chandra X-ray Observatory, the team found that the most massive stars in the nebula produce winds that slam into each other, create violent shocks, and infuse the region with 6-million-degree gas.
	www.science.psu.edu /journal/Spr2002/StellarWinds-Sp02.htm (834 words)

	Chandra Press Room :: Scientists Find X Rays from Stellar Winds That May Play Significant Role in Galactic Evolution :: ... (Site not responding. Last check: 2007-10-01)
		This multimillion-degree gas radiated as X rays is one of the long-sought sources of energy and elements in the Milky Way galaxy's interstellar medium.
		A team led by Leisa Townsley, a senior research associate in astronomy and astrophysics at Penn State University, uncovered this wind phenomenon in the Rosette Nebula, a stellar nursery.
		Fueling the fury are a handful of massive type-O and type-B stars at the core of the nebula, the most massive members of a populous "OB association" that also includes hundreds of lower- mass stars.
	chandra.harvard.edu /press/01_releases/press_090601wind.html (708 words)

	NASA/Marshall Solar Physics
		The source of the solar wind is the Sun's hot corona.
		The solar wind speed is high (800 km/s) over coronal holes and low (300 km/s) over streamers.
		ACE has a number of instruments that monitor the solar wind and the spacecraft team provides real-time information on solar wind conditions at the spacecraft.
	solarscience.msfc.nasa.gov /SolarWind.shtml (349 words)

	SPACE.com -- Star Wars: What Happens When Stellar Winds Collide
		The so-called stellar winds they generate are loaded with atomic particles.
		During close orbital skirmishes every eight years, the relatively empty space between the stars is compressed so much by the battling breezes that the few atoms which are there are forced together and made into dust.
		So the dust wraps around the weaker star and is blown into open space, somewhat in the way air goes around a fist stuck out a car window, said John Monnier of the Harvard-Smithsonian Center for Astrophysics.
	www.space.com /scienceastronomy/colliding_winds_020108.html (672 words)

	ScienceDaily: Mapping Orion's Winds
		The area of the Orion Nebula in the white box is enlarged to show some of the hundreds of shock waves that crisscross the region.
		New U. Of Colorado Astronomy Study Indicates Planet Formation May Be Rare In Universe (June 6, 2001) -- The vast majority of wannabe planets in the universe are likely destroyed by cosmic forces long before they have a chance to evolve from dusty disks circling their parent stars, according to...
		Stormy Cloud Of Star Birth Glows In New Spitzer Image (January 23, 2004) -- A dusty stellar nursery shines brightly in a new image from NASA's Spitzer Space Telescope, formerly known as the Space Infrared Telescope Facility.
	www.sciencedaily.com /releases/2006/01/060115174310.htm (1687 words)

	Stellar Winds and Circumstellar Envelopes
		The winds of main sequence stars like the Sun are now being studied for the first time by analysis of Lyman alpha absorption produced in their astrospheres by the interaction of the stellar wind with the interstellar gas.
		The figure on the left shows the extra absorption by hydrogen in the astrosphere of Alpha Centauri B (K1 V) compared to Proxima Centauri (dM6e) that shows that the mass loss rate for Alpha Centauri B is much larger than for Proxima Centauri.
		Analyze high resolution stellar UV and far-UV spectra obtained with the GHRS and STIS instruments on HST and the FUSE satellite.
	jilawww.colorado.edu /~jlinsky/winds.html (841 words)

	SPACE.com -- Stellar Wind X-Rays May Play Significant Role in Galactic Origins
		in the nebula produce winds that slam into each other, create violent shocks, and infuse the region with 6-million-degree gas.
		Fueling the fury are a handful of massive type-O and type-B stars at the core of the nebula, the most massive members of a populous "OB association" that also includes hundreds of lower-mass stars.
		Rather, the diffuse emission must be related to the way the stellar winds from OB associations dissipate their energy.
	www.space.com /scienceastronomy/astronomy/x-rays_galaxy_010905.html (820 words)

	Stellar Winds (Site not responding. Last check: 2007-10-01)
		Stellar winds and outflows provide another situation in which a nulling capability would be important.
		To take but one example, a nulling capability would have allowed the ring around SN 1987a to be identified and studies long before it reached a size observable from HST.
		In this case, as in most wind phenomena, the interesting physics occurs near the base of the outflow, where light from the central object ordinarily prevents detailed observations.
	www.ess.sunysb.edu /simswg/siswg/node76.html (102 words)

	Scientists find X-rays from stellar winds that may play significant role in galactic evolution
		Scientists find X-rays from stellar winds that may play significant role in galactic evolution
		Now, scientists using the Chandra X-ray Observatory have determined that colliding stellar winds create turmoil in this part of space, superheating gas in the region to 6 million degrees.
		The gas radiates as X-rays, which were observed by the research team.
	www.researchmatters.harvard.edu /story.php?article_id=303 (258 words)

	Amazon.com: Introduction to Stellar Winds: Books: Henny J. G. L. M. Lamers,Joseph P. Cassinelli (Site not responding. Last check: 2007-10-01)
		This long-awaited graduate textbook, written by two pioneers in the field, provides a comprehensive introduction to the observations, theories, and consequences of stellar winds.
		Stellar winds are the continuous outflow of material from stars.
		"Introduction to Stellar Winds" is simply one of the best book for those who need to know more about this topic.
	www.amazon.com /exec/obidos/tg/detail/-/0521595657?v=glance (933 words)

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