Question

How do astronomers study sun oscillations?

Answer 1

Different oscillation modes of pulsating stars penetrate to different depths inside the star. The observed frequency spectra are carefully characterized rendering information on the stellar interior.

Explanation:

The reason why stellar interiors can be probed from oscillations is that different oscillation modes penetrate to different depths inside the star. The observed frequency spectra are carefully characterized rendering information on the stellar interior.

Different pulsation modes are discerned: acoustic (p)-modes with high frequency for which pressure is the dominant restoring force and gravity (g)-modes with lower frequency for which buoyancy is the dominant restoring force.

Solar-type and red-giant stars show rich spectra of solar-like oscillations, pulsations which are excited and intrinsically damped by turbulence in the outermost layers of the convective envelopes. In main-sequence stars the oscillations are predominantly acoustic in nature. However, in the sub-giant and in particular the red-giant phase, g-modes, for which buoyancy is the restoring force, become visible providing further exquisite information on the interiors of these stars.
Details here:
https://www.spaceinn.eu/project/science/asteroseismology/

Real papers of studies:
http://asteroseismology.org/