2 papers
astro-ph.SR2018
Software tool for automatic detection of solar plages in the Coimbra Observatory spectroheliograms
T. Barata, S. Carvalho, I. Dorotovic +4
Full-disk spectroheliograms have been taken in Coimbra on a daily basis since 1926 in the Ca II K-line (K1 and K3). Later, in 1989, with the upgrade of the equipment it was possibl…
astro-ph.SR2012
Variation rate of sunspot area
R. Gafeira, C. C. Fonte, M. A. Pais +1
The emergence of the magnetic field through the photosphere has multiple manifestations and sunspots are the most prominent examples of this. One of the most relevant sunspot prope…