Solar limb faculae

¹ Institut für Physik, IGAM, Universitätsplatz 5, 8010 Graz, Austria e-mail: jkh@igam.uni-graz.at
² Universitäts-Sternwarte, Geismarlandstraße 11, 37083 Göttingen, Germany e-mail: ewiehr@uni-sw.gwdg.de

Received: 31 January 2005
Accepted: 22 March 2005

Abstract

We observe solar limb faculae at an unprecedented spatial resolution with the new 1 m Swedish Solar Telescope SST on La Palma. Speckle-reconstructed images are used to study 4475 limb facular grains simultaneously in the 430 nm G-band and the continuum up to only  from the limb (). No systematic contrast decrease is found even a few arcsec from the solar limb. The facular grains appear to be “projected” on the limb-side neighboring granules; approaching the disc center, the corresponding features occur as inter-granular G-band bright points. Independently, we took spectra with the French-Italian THEMIS telescope on Tenerife and find that the known “line-gap effect” from disc center disappears near the limb. Here, the facular continuum is enhanced whereas the normalized profiles are unchanged with respect to the undisturbed neighborhood.