2009 Karen Harvey Prize

The 2009 Karen Harvey Prize of the American Astronomical Society is awarded to Laurent Gizon "for his significant contributions and leadership in the development of local helioseismology techniques for the study of the Sun's internal dynamics."

The 2009 Harvey Prize lecture, delivered at the 2009 SPD meeting, is available here.

Helioseismology, Asteroseismology, and MHD Connections

by L Gizon, P Cally, JW Leibacher (Editors)

Hardcover: 638 pages/ Publisher: Springer (January 6, 2009)/ ISBN-13: 978-0387894812/ amazon.com

This volume presents a timely snapshot of the state of helio- and asteroseismology in the era when SOHO/MDI is about to be replaced by SDO/HMI and CoRoT is yielding its first long-duration light curves of thousands of stars. This Topical Issue of Solar Physics is inspired by two seminal conferences, HELAS II and SOHO19/GONG 2007, and was open for general submission on the core topics of these conferences. Three papers describing the current status of asteroseismology, global helioseismology, and local helioseismology were specially commissioned for the volume, and these set the context for the other contributions.

Solar Dynamics Observatory

Launch scheduled in 2009

The delay of NASA's next Mars mission will allow the $800 million solar observatory to move out of launch limbo and into an opening in the Atlas 5 rocket's manifest this October. Officials formally approved the change after negotiations with United Launch Alliance, the company that oversees the Atlas and Delta rocket fleets.

The 6,600-pound satellite will blast off from Cape Canaveral between Oct. 8 and Nov. 6. The launch period was originally assigned to the Mars Science Laboratory mission, but agency officials delayed the probe's launch two years earlier this month to overcome a rash of technical hurdles.

Research Highlight

Helioseismology probes sunspots

Sunspots have been seen on the surface of the Sun for thousands of years, and have been the subject of almost constant attention since the invention of the telescope. Despite this, much remains unknown because telescopes alone cannot see below the Sun's surface. Helioseismology, like terrestrial seismology, offers us a way to pierce the veil and "see" what lies hidden below. On the Earth, for example, we can look for oil deposits or cracks in the tectonic plates. Below sunspots we are interested in magnetic fields, flows and temperature changes. Observational data from both ground-based and satellite missions has been collected by various ground based consortia and space missions. The soon to be launched NASA satellite SDO will provide even higher quality data. In order to understand the observations scientists at the MPS have started performing numerical simulations of wave propagation through magnetic, fully nonlinear sunspots and have began comparing these with the data. The comparison allows us to learn about the structure of the sunspot.

A relevant paper is available with "open access" from the journal Solar Physics and can be downloaded here.

An image comparing the processed observations (top half) and the simulations (bottom half):

Research Highlight

Banana-doughnut tomography of the Sun

Finite-wavelength tomography of the Earth or the Sun critically relies on models of the sensitivity of seismic travel times to localized heterogeneities, as evidenced by the controversial discovery of plumes in the Earth's mantle.

We have used time-distance helioseismology to directly measure the spatial sensitivity of surface-gravity wave travel times to magnetic perturbations.

The data strongly speak in favour of 'banana-doughnut' theory according to which body-wave travel times are sensitive to the wave speed in a broad region surrounding the geometrical ray path.

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