Spitzer Space Telescope - General Observer Proposal #20772


Measuring Stellar Oscillations Using Spitzer:  P-Modes in the Hyades

Principal Investigator: Derek Buzasi
           Institution: US Air Force Academy

Co-Investigators: 
Heather Preston, US Air Force Academy                                 

Science Category: star clusters 
 Observing Modes: IracMap 
  Hours Approved: 16.0 

Abstract:
Observations of oscillations in solar-like stars are limited by the
fact that the level of variability involved is typically very small
(approximately 4-5 parts per million at optical wavelengths).  While
heroic efforts have made it possible to detect oscillations in a few
solar-like stars from the ground, the most astrophysically interesting
targets -- those in nearby open clusters -- are unreachable and likely
to remain so for many years.  Solar observations have shown that the
amplitude of oscillations seen in the 4.7-micron CO lines is nearly
two orders of magnitude higher than that seen at optical wavelengths.
For solar-like stars, such lines dominate the spectrum in IRAC Band 2.
In fact, we estimate that the amplitude of p-mode oscillations in that
band will be approximately 200  parts per million.  This is 40  times
the level in the optical, and easily accessible using Spizer.  We
propose a long time series of observations of the star VB 64, in the
Hyades.  We anticipate being able to detect a number of distinct
oscillation modes, and thus to determine the large separation.  In
combination with other, previously measured, physical parameters of VB
64, we expect to be able to determine values for mass, age, and
chemical composition which are at least an order of magnitude more
precise that has been previously possible for any star in the Hyades.