Stellar Oscillations Network Group

From the Sun to the Stars

SUMMARY Asteroseismology allows us to obtain quantitative information on the internal structure of stars, to compare stellar models to real stars in substantially more detail than now possible, to explore the behavior of matter under conditions which cannot be achieved on Earth, and to confront the discrepancy between stellar ages and the cosmological age from a new perspective. We propose to develop a ground-based network of (existing) telescopes and appropriate instrumentation and methodology to detect and study acoustic oscillations in solar type stars.

SONG, the Stellar Oscillations Network Group, is a broad, community based project with the goals of obtaining coordinated seismic observations of astrophysically important stars and, if necessary, of developing and deploying any specialized instrumentation that might be needed. While the focus is on solar type stars, we hope to draw on the experience and expertise of groups working on other classes of non-radially oscillating stars. Ultimately, the data produced through this program should return to the community.

We have begun to work to develop and organize a major, community based program to carry forward the scientific goals of asteroseismology. This is a natural extension of the study of oscillations in the Sun, so-called helioseismology, e.g. with the full GONG network. We have started with the establishment of a steering committee and have received approval to sponsor a session at the AAS meeting in Madison, Wisconsin in June 1996, to which we can invite the community and get the ball rolling. This particular AAS meeting was selected because meetings of the Solar Physics Division of the AAS and of the GONG Project will also take place in conjunction with the Madison meeting. Many of the astronomers who are interested in asteroseismology will already be attending the Madison meeting.

It is our vision that NOAO could participate in this venture through the contribution of significant amounts of telescope time on the Mayall 4-m telescope (and also on the 2.1-m, WIYN, SOAR, Blanco 4-m, and Gemini telescopes) and through our own expertise in the development of instrumentation and support of scientific programs. Coordination with existing observing networks and potential space missions will also be important. An effort of this magnitude can only succeed if it is truly community based.

The project will require activity on several fronts, including access to facilities and scheduling, development of prototype and working instrumentation, development of observing procedures and techniques which allow both great improvement in observing efficiency and in combining data from multiple observatories, development of appropriate data reduction and analysis tools, and improved stellar modeling. The effort will require such diverse expertise that it must necessarily encompass a broad community. We hope that much of the work can be done by scientists at a variety of institutions which are collaborating with the project.

Latest News


Some detailed information


Please send comments and questions on SONG to Caty Pilachowski will take care of these mails. Comments and suggestions on this home page should be directed to Christoph Keller at

Related home pages

Last change: June 24, 1998