Bibcode
Riethmüller, T. L.; Solanki, S. K.; Martínez-Pillet, V.; Hirzberger, J.; Feller, A.; Bonet, J. A.; Bello González, N.; Franz, M.; Schüssler, M.; Barthol, P.; Berkefeld, T.; del Toro Iniesta, J. C.; Domingo, V.; Gandorfer, A.; Knölker, M.; Schmidt, W.
Bibliographical reference
The Astrophysical Journal Letters, Volume 723, Issue 2, pp. L169-L174 (2010).
Advertised on:
11
2010
Citations
53
Refereed citations
43
Description
Bright points (BPs) are manifestations of small magnetic elements in the
solar photosphere. Their brightness contrast not only gives insight into
the thermal state of the photosphere (and chromosphere) in magnetic
elements, but also plays an important role in modulating the solar total
and spectral irradiance. Here, we report on simultaneous high-resolution
imaging and spectropolarimetric observations of BPs using SUNRISE
balloon-borne observatory data of the quiet Sun at the disk center. BP
contrasts have been measured between 214 nm and 525 nm, including the
first measurements at wavelengths below 388 nm. The histograms of the BP
peak brightness show a clear trend toward broader contrast distributions
and higher mean contrasts at shorter wavelengths. At 214 nm, we observe
a peak brightness of up to five times the mean quiet-Sun value, the
highest BP contrast so far observed. All BPs are associated with a
magnetic signal, although in a number of cases it is surprisingly weak.
Most of the BPs show only weak downflows, the mean value being 240 m
s-1, but some display strong down- or upflows reaching a few
km s-1.
Related projects
Solar and Stellar Magnetism
Magnetic fields are at the base of star formation and stellar structure and evolution. When stars are born, magnetic fields brake the rotation during the collapse of the mollecular cloud. In the end of the life of a star, magnetic fields can play a key role in the form of the strong winds that lead to the last stages of stellar evolution. During
Tobías
Felipe García