Oscillations on the Sun in regions with a vertical magnetic field
I. Sunspot umbral oscillations
Central Astronomical Observatory of Russian Academy of Sciences, 65 Pulkovo, 196 140 St. Petersburg, Russia
Corresponding author: email@example.com
Accepted: 29 January 2002
We have calculated the spectrum of eigenmodes of umbral oscillations. The eigenmodes of oscillations with periods from several tens of minutes (g-modes) to several tens of seconds (p-modes) have been found. It is shown that the 3-min umbral oscillations are p-modes modified by the magnetic field.
Key words: Sun: sunspots / Sun: oscillations / magnetohydrodynamics (MHD)
© ESO, 2002