Abstract
A solar faculae having an appearance of quite long-lived magnetic nodes can perform (as well as sunspots, chromospheric filaments, coronal loops) free oscillations, i.e., they can oscillate about the stable equilibrium position as a single whole, changing quasi-periodically magnetic field averaged over the section with periods from 1 to 4 hours. Kolotkov et al. (2017) described the case in which the average magnetic field strength of the facula node considerably decreased during observations of SDO magnetograms (13 hours), and, at the same time, its oscillations acquired a specific character: the fundamental mode of free oscillations of the facula considerably increased in amplitude (by approximately two times), while the period of oscillations increased by three times. At the end of the process, the system dissipated. In this work, we present the exact solution of the equation of small-amplitude oscillations of the system with a time-variable rigidity, describing the oscillation behavior at which the elasticity of the system decreases with time, while the period and amplitude of oscillations grow.
Similar content being viewed by others
References
Efremov, V.I., Parfinenko, L.D., Solov’ev, A.A., and Kirichek, E.A., Long-period oscillations of sunspots observed by SOHO/MDI, Sol. Phys., 2014, vol. 289, no. 6, pp. 1983–1998.
Efremov, V.I., Parfinenko, L.D., and Solov’ev, A.A., Ultra low-frequency oscillations of a solar filament observed by the GONG network, Sol. Phys., 2016, vol. 291, no. 11, pp. 3357–3367.
Foullon, C., Verwichte, E., and Nakariakov, V.M., Ultralong- period oscillations in EUV filaments near to eruption: Two-wavelength correlation and seismology, Astrophys. J., 2009, vol. 700, no. 2, pp. 1658–1665.
Kolotkov, D.Y., Smirnova, V.V., Strekalova, P.V., Riehokainen, A., and Nakariakov, V.M., Long-period quasiperiodic oscillations of a small-scale magnetic structure on the Sun, Astron. Astrophys., 2017, vol. 598, id L2.
Nayfeh, A.H., Introduction to Perturbation Techniques, New York: Wiley-Interscience, 1981.
Yuan, D., Nakariakov, V.M., Chorley, N., and Foullon, C., Leakage of long-period oscillations from the chromosphere to the corona, Astron. Astrophys., 2011, vol. 533, id A116.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Solov’ev, A.A., Kirichek, E.A. & Efremov, V.I. Free Oscillations of the Facula Node at the Stage of Slow Dissipation. Geomagn. Aeron. 57, 1101–1104 (2017). https://doi.org/10.1134/S0016793217080229
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0016793217080229