Convectively driven vortex flows in the Sun

by
Bonet, J. A.Márquez, I.Sanchez Almeida, J., Cabello, I. and Domingo, V.


ABSTRACT: We have discovered small whirlpools in the Sun, with a size similar to the terrestial hurricanes (~<0.5Mm). The theory of solar convection predicts them, but they had remained elusive so far. The vortex flows are created at the downdrafts where the plasma returns to the solar interior after cooling down, and we detect them because some magnetic bright points (BPs) follow a logarithmic spiral in their way to be engulfed by a downdraft. Our disk center observations show 0.009 vortexes per Mm^2, with a lifetime of the order of 5 min, and with no preferred sense of rotation. They are not evenly spread out over the surface, but they seem to trace the supergranulation and the mesogranulation. These observed properties are strongly biased by our type of measurement, unable to detect vortexes except when they are engulfing magnetic BPs.

Full paper:   http://xxx.lanl.gov/abs/0809.3885

MOVIE:
29 Sep. 2007. Whirlpool in quiet granulation at the solar disk center observed in G-band.
SST, Observatorio del Roque de los Muchachos (La Palma) (*)
Multiframe blind deconvolution was employed for data restoration.
The movie displays 7 min in the Sun (cadence 15 s)
The bar at the lower left corner of the image corresponds to one Mm on the Sun.
size: 232 x 212 px.
duration: 2 s.

*The Swedish 1-m Solar Telescope (SST) is operated in the island of La Palma by the Institute for Solar Physics of the Royal Swedish Academy of Sciences in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

G-band
430.5 nm
(bandwidth 1.1nm)
(1.3 Mb)
G-band
430.5 nm
(bandwidth 1.1nm)
(8.4 Mb)
gband gband
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Contact address: imr@iac.es