Sunspots are the most readily visible manifestations of solar magnetic field concentrations
and of their interaction with the Sun's plasma. Although sunspots have been extensively …

The current state of our knowledge, and ignorance, of the nature of oscillations in sunspots
is surveyed. An effort is made to summarize the robust aspects of both the observational and …

First results from the VIRGO experiment (Variability of solar IRradiance and Gravity
Oscillations) on the ESA/NASA Mission SOHO (Solar and Heliospheric Observatory) are …

Recent observational evidence for magnetic field direction effects on helioseismic signals in
sunspot penumbrae is suggestive of magnetohydrodynamic (MHD) mode conversion …

The forward problem of time-distance helioseismology is computing travel-time
perturbations that result from perturbations to a solar model. We present a new and …

Images of an active region on the far side of the sun were derived by applying seismic
holography to recent helioseismic observations from space. Active regions are the centers of …

We measure the mean frequencies of acoustic (p-mode) waves propagating toward and
away from the poles of the Sun from observations made with the Solar Oscillations …

While sunspots are easily observed at the solar surface, determining their subsurface
structure is not trivial. There are two main hypotheses for the subsurface structure of …

The solar atmosphere is known to be replete with magneto-hydrodynamic wave modes, and
there has been significant investment in understanding how these waves propagate through …

We use a data set of exceptionally high quality to measure oscillations of Doppler velocity,
intensity, and the vector magnetic field at photospheric heights in a sunspot. Based on the …