Driving g-mode pulsations in gamma doradus variables

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Pulsars, Unsteady Flow, Convection, Radiance, Scutum Constellation, Viscosity

Scientific paper

The (gamma) Doradus stars are a newly-discovered class of gravity-mode pulsators which lie just at or beyond the red edge of the (delta) Scuti instability strip. We present the results of calculations which predict pulsation instability of high-order g-modes with periods between 0.4 and 3 days, as observed in these stars. The pulsations are driven by the modulation of radiative flux by convection at the base of a deep envelope convection zone. Pulsation instability is predicted only for models with temperatures at the convection zone base between (approximately)200,000 and (approximately)480,000 K. The estimated shear dissipation due to turbulent viscosity within the convection zone, or in an overshoot region below the convection zone, can be comparable to or even exceed the predicted driving, and is likely to reduce the number of unstable modes, or possibly to quench the instability. Additional refinements in the pulsation modeling are required to determine the outcome. A few Doradus stars have been observed that also pulsate in (delta) Scuti-type p-modes, and at least two others have been identified as chemically peculiar. Since our calculated driving region is relatively deep, Doradus pulsations are not necessarily incompatible with surface abundance peculiarities or with (delta) Scuti p-mode pulsations driven by the H and He-ionization (kappa) effect. Such stars will provide useful observational constraints on the proposed Doradus pulsation mechanism.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Driving g-mode pulsations in gamma doradus variables does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Driving g-mode pulsations in gamma doradus variables, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Driving g-mode pulsations in gamma doradus variables will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1107919

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.