Hélène R. Dickel - "Matter between the Stars"

American Astronomical Society - Harlow Shapley Visiting Lecturer (1981-2007)
American Chemical Society Tour Speaker (1986-2008)

Adjunct Professor of Physics and Astronomy
University of New Mexico
    and
Emerita Research Professor of Astronomy
University of Illinois


MATTER BETWEEN THE STARS

The space between the stars is not a perfect vacuum but contains a small amount of hydrogen plus various contaminating atoms and molecules. This material is collected into giant cloud complexes. Although typical densities are only a few particles per cubic centimeter, the volumes are so vast that the clouds often contain several thousand times the mass of the sun. Such regions are continually in violent activity - material in some spots is contracting to create brand new stars, other clouds are bursting apart at thousands of kilometers per second from the sites of exploding stars, and many areas are being heated and disturbed by the excitation of starlight and interstellar shock waves. We shall describe the results of recent research which is beginning to see order in this chaos: old stars throw off heavy elements which block energy transfer, enhancing the process of star formation. The new stars in turn excite their surroundings and eventually spew their material back into the interstellar medium to complete the cycle.

Need: Power Point Projector and Computer (pc)
Alternative titles to above lecture:
"Cosmic Recycling Center"
"Birth and Death of Stars"

AAS: Evening Public Lecture

ACS: Public Lecture (ACS Topic 1A): Subject Category AC, GSc, GP; Audience Level 2,3,4