activity
20172022
most citedAnalysis of full disc Ca II K spectroheliograms. II. Towards an accurate assessment of long-term variations in plage areas

58 citations · 290 across the 8 of their papers we have counts for

collaborators

12 papers

astro-ph.SR2022

Rome Precision Solar Photometric Telescope: precision solar full-disk photometry during solar cycles 23-25

Ilaria Ermolli, Fabrizio Giorgi, Theodosios Chatzistergos

The Rome Precision Solar Photometric Telescope (Rome/PSPT) is a ground-based telescope engaged in precision solar photometry. It has a 27-year database of full-disk images of the p…

astro-ph.SR202249 cited

Full-disc Ca II K observations -- a window to past solar magnetism

Theodosios Chatzistergos, Natalie A. Krivova, Ilaria Ermolli

First such observations were made in 1892 and since then various sites around the world have carried out regular observations, with Kodaikanal, Meudon, Mt Wilson, and Coimbra being…

astro-ph.SR202224 cited

Scrutinizing the relationship between plage areas and sunspot areas and numbers

Theodosios Chatzistergos, Ilaria Ermolli, Natalie A. Krivova +3

Studies and reconstructions of past solar activity require data on sunspots as well as faculae/plage and network. Such data are also important for understanding the magnetic activi…

astro-ph.SR202027 cited

Modelling solar irradiance from ground-based photometric observations

Theodosios Chatzistergos, Ilaria Ermolli, Fabrizio Giorgi +2

Total solar irradiance (TSI) has been monitored from space since 1978. The measurements show a prominent variability in phase with the solar cycle, as well as fluctuations on times…

astro-ph.SR202055 cited

Analysis of full disc Ca II K spectroheliograms III. Plage area composite series covering 1892-2019

Theodosios Chatzistergos, Ilaria Ermolli, Natalie A. Krivova +16

We derive the plage area evolution over the last 12 solar cycles employing data from all Ca II K archives available publicly in digital form known to us, including several as yet u…

astro-ph.SR2019

Delving into the Historical Ca II K Archive from the Kodaikanal Observatory: the Potential of the Most Recent Digitised Series

Theodosios Chatzistergos, Ilaria Ermolli, Sami K. Solanki +4

Full-disc Ca II K photographic observations of the Sun carry direct information about the evolution of solar-plage regions for more than a century and are therefore a unique datase…