
	Where results make sense

Topic: Helioseismology

In the News (Sun 12 Oct 08)

Bank of America 500

Jeff Burton

Kimi Raikkonen

Robert Mugabe

Zaheer Khan

Angelina Jolie

Brett Myers

Manmohan Singh

Charlie Manuel

Japanese Grand Prix

	Helioseismology - Wikipedia, the free encyclopedia
		Helioseismology is the study of the propagation of pressure waves in the Sun.
		Helioseismology was able to rule out the possibility that the solar neutrino problem was due to incorrect models of the interior of the Sun.
		Features revealed by helioseismology include that the outer convective zone and the inner radiative zone rotate at different speeds to generate the main magnetic field of the Sun, and that the convective zone has "jet streams" of plasma thousands of kilometers below the surface.
	en.wikipedia.org /wiki/Helioseismology (829 words)

	NSO/GONG: Helioseismology
		Helioseismology utilizes waves that propagate throughout the Sun to measure, for the first time, the invisible internal structure and dynamics of a star.
		While the physics is rather different, helioseismology uses acoustic waves to probe the interior of the Sun in a way roughly analogous to medicine using x-rays to do a CAT scan of the human body.
		As it was in the past with optical spectroscopy, helioseismology is serving as a springboard to the study of the interiors of other stars as well.
	gong.nso.edu /info/helioseismology.html (2159 words)

	Helioseismology
		The primary physics in both seismology and helioseismology are wave motions that are excited in the body's (Earth or Sun) interior and that propagate through a medium.
		Helioseismology is currently the best method for verifying those theories and for understanding the structure and interior processes within a star.
		To identify the oscillation modes, many helioseismology experiments start with a velocity picture of the Sun, where each pixel tracks the velocity of a small area on the solar surface by fixing on the Doppler shift of a spectrum line.
	soi.stanford.edu /results/heliowhat.html (1489 words)

	Scientific American: The GONG Show (Site not responding. Last check: 2007-10-20)
		Helioseismology has enabled researchers to create images of the invisible structure and processes deep inside the sun.
		Gough is a pioneer in the emerging field of helioseismology.
		Helioseismology is still a young field, so it is not surprising that so many questions remain to be answered.
	www.sciam.com /print_version.cfm?articleID=0001B951-A50F-1C76-9B81809EC588EF21 (1012 words)

	[No title] (Site not responding. Last check: 2007-10-20)
		With these results, and the detection in the late 1970s of five-minute oscillations propagating throughout the entire Sun, the potential for using observations of these surface oscillations to probe the solar interior was evident, and helioseismology was born.
		And finally, local helioseismology has provided information about the subsurface structure of solar active regions and their emergence, and even led to monitoring of solar activity on the far side of the sun.
		Older participants in the field will enjoy being reminded of how helioseismology has developed; younger scientists get an introduction to the history of their subject, and the general reader is given a fascinating overview of one of the newest and most active fields of astrophysics, including enjoyable cameos of some of the participants.
	www.nature.com /news/2004/040105/pf/427103a_pf.html (994 words)

	Sounding the Sun: Helioseismology
		Helioseismology is the study of the interior of the Sun from observations of the vibrations of its surface.
		Helioseismology is rather like trying to understand how a piano is built from the sounds that it makes when you drop it down a flight of stairs.
		The two principal kinds of information one can extract from helioseismic data are spatial averages of the speed with which seismic waves travel in the Sun, and spatial averages of the speed with which parts of the Sun are moving relative to other parts (because the seismic waves are advected with the material).
	www.stat.berkeley.edu /~stark/Seminars/Aaas/helio.htm (2370 words)

	helioseismology
		Helioseismology will reveal the nature of stellar convection and how rotation changes with depth.
		For stars like the Sun, almost all the energy released by fusion in the core is brought to the surface by convection currents whose large cells are hidden from view.
		Among the largest helioseismology projects is the Global Oscillation Network Group (GONG).
	www.daviddarling.info /encyclopedia/H/helioseismology.html (337 words)

	Lynne's Place: Helioseismology (Site not responding. Last check: 2007-10-20)
		Helioseismology, the study of solar oscillations, began as recently as 1960 with the discovery that the Sun was covered in little patches that seemed to oscillate with periods near five minutes.
		As the theories of helioseismology were developed, it was discovered that the solar convective envelope was much deeper than was predicted from standard solar models.
		Other major triumphs of helioseismology have been determining the angular velocity and the adiabatic soundspeed throughout much of the interior of the Sun.
	www.maths.qmw.ac.uk /~lms/research/seismic.html (251 words)

	2.2 Local helioseismology
		Local helioseismology has also been used to study the acoustic and flow structure underlying sunspots (Kosovichev et al.
		There is much promise that with improved instrumentation and analysis techniques local helioseismology can do better and may soon provide information on flow structure, magnetic activity, and thermal asphericity as deep as the tachocline (Gizon and Birch, 2005).
		Although local helioseismology can currently only provide detailed dynamical information for the outer few percent of the solar interior, the large-scale flow patterns it reveals may extend deeper into the convective envelope.
	solarphysics.livingreviews.org /Articles/lrsp-2005-1/articlesu2.html (473 words)

	Physics at Minnesota:
		In its infancy helioseismology demonstrated that the solar convection zone is about twice as deep as was generally thought to be the case before 1977.
		Turning to the dynamics of the solar interior, helioseismology has also provided measurements of the radial and latitudinal profiles of the sun's angular velocity over the outer half of the solar interior (as measured by radius).
		Finally, helioseismology is a truly global enterprise with numerous international ground-based observing networks now in daily operation and with the ESA-NASA SOHO spacecraft just beginning to observe the solar oscillations on a continuous bases from the Ll Lagrangian point with a complement of three helioseismology instruments.
	www.physics.umn.edu /news/archive9596.html?printer=yes& (1685 words)

	HISTORY OF THE 60 FOOT SOLAR TOWER
		Helioseismology got its start in the early 1960s when CalTech physicist Robert Leighton discovered the 5-minute oscillation on the surface of the sun.
		When Leighton analyzed several of these difference images, he noticed that both large scale and small scale features on the solar surface were oscillating in a period of 296 seconds (or roughly 5 minutes), and at a speed of 500m/s.
		These solar oscillations quickly became known as solar quakes, hence the study of helioseismology was born.
	physics.usc.edu /solar/history.html (677 words)

	Stanford SOLAR Center -- Helioseismology Tours
		A junior-high to high-school-level helioseismology tour written by Jørgen Christensen-Dalsgaard and his colleagues at Aarhus University, Denmark: Helio- and Asteroseismology.
		A high-school-level helioseismology overview written by the GONG Project: Helioseismology.
		A college-level helioseismology overview written by Jeremy K. Zoss (Rice University): Theoretical Aspects of Helioseismology.
	solar-center.stanford.edu /heliopage.html (280 words)

	The Solar FAQ: Solar Neutrinos and Other Solar Oddities
		Helioseismology is so precise today, that comparison between theoretical calculations and measurements require a better knowledge of the solar radius than is currently available.
		Furthermore, as the sun is not a solid body, it does not have a well-defined surface at which to measure the radius (Castellani and Degl'Innocenti and Fiorentini 1998).
		Helioseismology has also confirmed, beyond reasonable doubt, that the sun's interior is fluid all the way through; a crystalline interior would be glaringly obvious in their data.
	www.talkorigins.org /faqs/faq-solar.html (15805 words)

	Progress in Local Helioseismology (Site not responding. Last check: 2007-10-20)
		By comparison, the efforts in local helioseismology, defined as the study of subsurface nonaxisymmetric phenomena, have been relatively modest.
		The first attempts at local helioseismology were really scaled-down versions of the global techniques, in which mode measurements were made over a restricted area.
		The current state of the different methods of local helioseismology will be reviewed.
	www.aas.org /publications/baas/v29n2/spd28/abs/S010001.html (254 words)

	Alibris: Helioseismology
		Helioseismology from Space: The Proceedings of the Cospar Interdisciplinary Scientific Commission E (Meeting E7), of the Cospar 28th Plenary Meeti
		This book focuses on the recent advances in our understanding of solar convection and activity, and on new methods and results of helioseismic diagnostics of the internal structures and dynamics of solar convection and active regions.
		The methods of local helioseismology (time-distance tomography, ring-diagram analysis, acoustic imaging, and...
	www.alibris.com /search/books/subject/Helioseismology (419 words)

	HELIOSEISMOLOGY
		Helioseismology studies the wave oscillations in the Sun.
		Since the waves are created deep inside the Sun, scientists use these waves to understand the Sun's interior.
		That is why helioseismology is called a diagnostic.
	www.windows.ucar.edu /tour/link=/sun/Solar_interior/Helioseismology/helioseismology.html (177 words)

	Can Gravity be Induced? (Site not responding. Last check: 2007-10-20)
		I suggest that the temperature and luminosity gradient drop with proximity to the non-space solar interior.
		The same is true for Helioseismology; the observer is blind to the interior and so the information is interpreted in the light of present concepts of solar theory.
		Helioseismologists have discovered a condition in the Sun's shallower layers which is at variance with conventional core models: Through frequency splittings resulting from the Sun's rotation, it is observed that the rotation actually decreases with depth.
	www.goodfelloweb.com /nature/cgbi (3773 words)

	HELIOSEISMOLOGY
		Helioseismology studies the wave oscillations in the Sun, similarly to the study on the seismic waves on Earth.
		These (sound) waves are affected by the physical conditions (density and temperature) and deep turbulent motions inside the Sun.
		The observation of these wave patterns can give insight to the structure of the interior of the Sun.
	www.windows.ucar.edu /sun/Solar_interior/Old_stuff/ls (388 words)

	Helioseismology IV - Solar Physics Division - AAS [SP]
		We investigate the recent claim by Lisle, Rast, and Toomre (2004, ApJ) that supergranules tend to align preferentially in the north-south direction.
		We repeat their analysis with an extensive set of maps of the horizontal divergence of flow fields derived from time-distance helioseismology.
		It has been supported by grants from the Living with a Star and Supporting Research and Technology programs of the National Aeronautics and Space Administration and the Stellar Astronomy and Astrophysics branch of the National Science Foundation.
	www.agu.org /meetings/sm05/sm05-sessions/sm05_SP24A.html (1271 words)

	sp22a in sm01
		SN: Helioseismology and Variability of the Solar Interior II D C Braun, CoRA Division, Northwest Research Assoc., Inc.; N Hurlburt, Lockheed Martin Solar and Astrophysics Lab.
		It substantially extends diagnostic capabilities of the `global' helioseismology which is based on normal mode frequencies and can recover only 2D azimuthally averaged structures and flows.
		Recently developed approaches to the local-area helioseismology (time-distance helioseismology, acoustic imaging, holography, ring-diagram analysis) study evolution of particular regions on the Sun by tracking them with solar rotation.
	www.agu.org /cgi-bin/SFgate/SFgate?&listenv=table&multiple=1&range=1&directget=1&application=sm01&database=/data/epubs/wais/indexes/sm01/sm01&maxhits=200&="SP22A" (2287 words)

	Max Planck Society - PhD Scholarship in Helioseismology
		The successful candidate is expected to carry out research in the field of helioseismology under the supervision of Dr. Laurent Gizon.
		Applications or inquiries should be addressed directly to Dr. Laurent Gizon at lgizon@solar.stanford.edu preferably in PDF or PS format.
		Applications for this particular PhD scholarship (helioseismology) should include a curriculum vitae, a short statement of interest, and the contact informations of two former professors.
	www.mpg.de /english/careerOpportunities/jobOffers/extern/aeronomie/stellenangebot7 (191 words)

	Max Planck Society - Research Scientist in Helioseismology
		The successful candidate is expected to take an active role in the development of a newly established research group in helioseismology, to conduct original research, and to advise PhD students.
		Applicants should have a PhD in physics or astrophysics and, preferably, a record of postgraduate research in helioseismology or asteroseismology.
		Salary and benefits will be calculated according to the BAT IIa/Ib scale of the German civil service.
	www.mpg.de /english/careerOpportunities/jobOffers/extern/aeronomie/stellenangebot8 (141 words)

	Douglas C. Braun: research and publications, local helioseismology, seismic holography, far-side imaging
		The web site, and complete set of material, for the school is available here.
		Schunker, H., Braun, D.C., Lindsey, C., and Cally, P.S. "Local Helioseismology of Inclined Magnetic Fields and the Showerglass Effect," in
		Lindsey, C. and Braun D.C. "The Acoustic Showerglass," Local Helioseismology Comparison (LoHCo) Workshop 7, Tucson AZ Feb 10-11, 2004 powerpoint file
	www.cora.nwra.com /~dbraun (845 words)

	standard solar models, helioseismology and solar models, and solar neutrinos
		The complementarity of helioseismology and solar neutrino experiments is demonstrated by constructing a solar model with a drastically altered nuclear energy generation that eliminates entirely the important high-energy
		Models that do not include diffusion, or in which the interior of the sun is assumed to be significantly mixed, are ruled out by the helioseismology.
		We conclude that helioseismology provides strong evidence for element diffusion and therefore for the somewhat larger solar neutrino event rates calculated in this paper.
	www.sns.ias.edu /~jnb/Papers/Preprints/solarmodels.html (3129 words)

	Peter Giles
		For more information about helioseismology, visit the SOI tutorial.
		Meeting of the Solar Physics Division of the AAS, Bozeman, MT Oral Presentation: Solar Meridional Circulation and Rotation Determined by Time-Distance Helioseismology using MDI Data From SOHO (abstract)
		Helioseismology Workshop, JILA, University of Colorado at Boulder, CO
	quake.stanford.edu /~giles/giles.html (465 words)

	The Sun and Stellar Structure (Site not responding. Last check: 2007-10-20)
		The GONG homepage at the National Optical Astronomy Observatories is a must see.
		A concise fact sheet for GONG is available, as well as, information about helioseismology in general.
		The Solar Oscillations Investigation at Stanford is another major centre for helioseismology research.
	www.star.ucl.ac.uk /~idh/STROBEL/starsun/strsunc.htm (2147 words)

	Encyclopedia of Astronomy and Astrophysics » Solar Interior: Local Helioseismology (Site not responding. Last check: 2007-10-20)
		This article describes how we use acoustic waves to study the subsurface properties of particular areas of the Sun.
		Local helioseismology is not as well developed as the more mature area of study, global HELIOSEISMOLOGY.
		New techniques are still being suggested and developed.This article will discuss some of these techniques and the most solid of the inferences about the SOLAR INTERIOR derived fr...
	eaa.iop.org /index.cfm?action=summary&doc=eaa/2250@eaa-xml (89 words)

	INI : Abstracts : MSIW01 : Forward Modeling for Local Helioseismology (Site not responding. Last check: 2007-10-20)
		In order to interpret measurements made with local helioseismology it is crucial to understand the sensitivity of these measurements to different types of perturbations to a solar model.
		Local helioseismic measurements are sensitive not only to subsurface mass flows, sound-speed variations, and magnetic field, but also to local changes in the wave damping and excitation rates.
		I will show example calculations of the sensitivity of travel-times measured by time-distance helioseismology and phase shifts measured by acoustic holography to flows, sound speed perturbations, and local changes in the wave excitation and damping rates.
	www.newton.cam.ac.uk /programmes/MSI/Abstract1/birch.html (160 words)

Try your search on: Qwika (all wikis)