Last updated on April 17, 2014 at 17:30 EDT
Fluid Dynamics to Study Stars Image 1
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Fluid Dynamics to Study Stars (Image 1)

June 9, 2010
Fluid Dynamics to Study Stars (Image 1) The strength of the gravitational field at various locations in the orbital plane of the binary star system can be represented by the depth and structure of two overlapping "potential wells," and the size of each star can be represented by the level to which fluid fills each well. Mass transfer occurs when the fluid of one star completely fills its own potential well then spills over into the potential well (onto the surface) of the other star. [Image 1 in a series of 6. See Image 2.] More about this Image A team lead by Joel Tohline, professor of astronomy at Louisiana State University (LSU), uses computational fluid dynamics techniques to analyze how the structure of stars is altered by strong tidal forces in close binary star systems. Of particular interest is the situation when gas is tidally stripped from the surface of one star (the "donor") and falls directly onto the surface of the other star (the "accretor"). The ultimate fate of such mass-transferring binary star systems appears to depend on the ratio of the masses of the two stars (q = Mdonor/Maccretor) at the instant a mass-transfer event begins. In this set of images (and accompanying movie), the time-evolving structure of both stars is illustrated by rendering four nested isodensity surfaces: green/yellow identifies regions of highest mass-density; blue identifies regions of lowest mass-density. The collaborative team at LSU includes: Mario D'Souza, Juhan Frank, Luis Lehner, Patrick Motl, and Jorge Pullin. Technical details about these simulations can be found at http://arxiv.org/abs/astro-ph/0512137. This research has been supported in part by grants AST-0407070 and PHY-0326311 from the National Science Foundation and grant NAG5-13430 from NASA, and in part by allocations of supercomputing time at the National Center for Supercomputer Applications (NCSA) at the University of Illinois and at the Center for Computation and Technology (CCT) at LSU. (Date of Image: July 2005)