Astronomy and Astrophysics – Astrophysics
Scientific paper
1994-03-08
Astron.Astrophys.293:87,1995
Astronomy and Astrophysics
Astrophysics
Accepted for publication in Astronomy and Astrophysics. (19 pages, uuencoded and compressed PostScript; hardcopy on request fr
Scientific paper
There are no good predictions for the amplitudes expected from solar-like oscillations in other stars. In the absence of a definitive model for convection, which is thought to be the mechanism that excites these oscillations, the amplitudes for both velocity and luminosity measurements must be estimated by scaling from the Sun. In the case of luminosity measurements, even this is difficult because of disagreement over the solar amplitude. This last point has lead us to investigate whether the luminosity amplitude of oscillations (dL/L) can be derived from the velocity amplitude v_osc. Using linear theory and observational data, we show that p-mode oscillations in a large sample of pulsating stars satisfy (dL/L)_bol proportional to v_osc/T_eff. Using this relationship, together with the best estimate of v_osc(Sun) = (23.4 +/- 1.4) cm/s, we estimate the luminosity amplitude of solar oscillations at 550 nm to be dL/L = (4.7 +/- 0.3) ppm. Next we discuss how to scale the amplitude of solar-like (i.e., convectively-powered) oscillations from the Sun to other stars. The only predictions come from model calculations by (Christensen-Dalsgaard & Frandsen, Sol. Phys. 82, 469). However, their grid of stellar models is not dense enough to allow amplitude predictions for an arbitrary star. Nevertheless, although convective theory is complicated, we might expect that the general properties of convection -- including oscillation amplitudes -- should change smoothly through the colour-magnitude diagram. Indeed, we find that the velocity amplitudes predicted by the model
Bedding Tim R.
Kjeldsen Hans
No associations
LandOfFree
Amplitudes of Stellar Oscillations: The Implications for Asteroseismology 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 Amplitudes of Stellar Oscillations: The Implications for Asteroseismology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Amplitudes of Stellar Oscillations: The Implications for Asteroseismology will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-59207