Phone: 406-994-6174
Fax: 406-994-4452
Barnard Hall (EPS) Room , MSU, Bozeman, 59717-3840, MT

Related Links:
Astronomy Picture of the Day
New papers about neutron stars
Lecture for undergraduates on neutron stars
The Extreme Gravity Institute (XGI)


Selected Honors, Awards, and Public Outreach/Service:

  •  Director's Fellowship, Los Alamos National Laboratory (1991-1993)
  •  Award for Outstanding Graduate Level Instructor (2009) - selected by the students
  •  Kevin Westfold Scholarship - Monash University, Australia (2014)
  •  Award for Outstanding Undergraduate Level Instructor (2015) - selected by the students 

Biographical Sketch:

  • Ph.D., Astrophysics, 1991 University of Illinois at Urbana-Champaign
  • M.S., Astrophysics, 1987 University of Illinois at Urbana-Champaign
  • B.S., Physics, 1984 University of Missouri-Rolla

Past graduate students:

  •  Michelle Larson (Ph.D 2001)
  •  Steve Price (Ph.D 2012)


Earth Layers

One of the outstanding questions in modern physics research concerns the state of matter above nuclear density (~1014 g cm-3). It is unknown whether matter at these densities is in the form of nucleons, quarks, kaons, hyperons, or other exotica. Laboratory experiments are only beginning to shed light on this question. Whatever the state of superdense matter, it exists in abundance in the neutron stars we have throughout our galaxy (now over ~2000 known). My research uses neutron stars as laboratories with which to study matter at densities currently inaccessible in terrestrial laboratories. The conditions in a neutron star are extreme. The average density is such that 1 cm3 of material has a mass exceeding 108 metric tons. Typical internal temperatures are ~108 K and above. A neutron star contains about a solar mass of superconducting liquid (denoted SFn in the figure below), permeated by a magnetic field that is at least one hundred thousand times larger than what can be produced even briefly on Earth. Neutron stars have violent lives; they can suffer starquakes, produce jumps in spin rate, accrete matter from other stars or the interstellar medium, and produce explosions. Some of these explosions more than 1047 ergs in gamma rays (the amount of energy emitted by the Sun in a million years).  

I am currently studying the possibility that the superfluid liquid interior is turbulent. I am also studying how neutron stars cool with time and explosions from highly-magnetized neutron stars. I am working to assemble a comprehensive picture of the inner workings of these fascinating objects.  
I have many projects for students! 

Selected Publications:


  • NASA Astrophysics Theory Program, 2012-2017
  • NSF Astronomical Sciences, 2012-2017