EDP Sciences
Free access
Volume 386, Number 2, May I 2002
Page(s) 653 - 657
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20020279

A&A 386, 653-657 (2002)
DOI: 10.1051/0004-6361:20020279

Oscillations on the Sun in regions with a vertical magnetic field

I. Sunspot umbral oscillations
V. I. Zhukov

Central Astronomical Observatory of Russian Academy of Sciences, 65 Pulkovo, 196 140 St. Petersburg, Russia

(Received 29 August 2001 / 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