| New reconstruction of the sunspot group numbers since 1739 using direct calibration and “backbone” methods T Chatzistergos, IG Usoskin, GA Kovaltsov, NA Krivova, SK Solanki Astronomy & Astrophysics 602, A69, 2017 | 90 | 2017 |
| Analysis of full disc Ca II K spectroheliograms-II. Towards an accurate assessment of long-term variations in plage areas T Chatzistergos, I Ermolli, NA Krivova, SK Solanki Astronomy & Astrophysics 625, A69, 2019 | 50 | 2019 |
| Recalibration of the sunspot-number: status report F Clette, L Lefèvre, T Chatzistergos, H Hayakawa, VMS Carrasco, R Arlt, ... Solar Physics 298 (3), 44, 2023 | 49 | 2023 |
| Analysis of full disc Ca II K spectroheliograms-I. Photometric calibration and centre-to-limb variation compensation T Chatzistergos, I Ermolli, SK Solanki, NA Krivova Astronomy & Astrophysics 609, A92, 2018 | 40* | 2018 |
| Analysis of full-disc Ca II K spectroheliograms-III. Plage area composite series covering 1892–2019 T Chatzistergos, I Ermolli, NA Krivova, SK Solanki, D Banerjee, T Barata, ... Astronomy & Astrophysics 639, A88, 2020 | 38 | 2020 |
| Recovering the unsigned photospheric magnetic field from Ca II K observations T Chatzistergos, I Ermolli, SK Solanki, NA Krivova, F Giorgi, KL Yeo Astronomy & Astrophysics 626, A114, 2019 | 34 | 2019 |
| Modelling a multi-spacecraft coronal mass ejection encounter with EUHFORIA E Asvestari, J Pomoell, E Kilpua, S Good, T Chatzistergos, M Temmer, ... Astronomy & Astrophysics 652, A27, 2021 | 27 | 2021 |
| Full-disc Ca ii K observations—A window to past solar magnetism T Chatzistergos, NA Krivova, I Ermolli Frontiers in Astronomy and Space Sciences 9, 1038949, 2022 | 24 | 2022 |
| Long-term changes in solar activity and irradiance T Chatzistergos, NA Krivova, KL Yeo Journal of Atmospheric and Solar-Terrestrial Physics 252, 106150, 2023 | 23 | 2023 |
| Modelling solar irradiance from ground-based photometric observations T Chatzistergos, I Ermolli, F Giorgi, NA Krivova, CC Puiu Journal of Space Weather and Space Climate 10, 45, 2020 | 23 | 2020 |
| Dependence of the sunspot-group size on the level of solar activity and its influence on the calibration of solar observers IG Usoskin, GA Kovaltsov, T Chatzistergos Solar Physics 291 (12), 3793-3805, 2016 | 23 | 2016 |
| Delving into the Historical Ca ii K Archive from the Kodaikanal Observatory: The Potential of the Most Recent Digitized Series T Chatzistergos, I Ermolli, SK Solanki, NA Krivova, D Banerjee, BK Jha, ... Solar Physics 294 (10), 145, 2019 | 22 | 2019 |
| Reconstructing solar irradiance from historical Ca II K observations-I. Method and its validation T Chatzistergos, NA Krivova, I Ermolli, KL Yeo, S Mandal, SK Solanki, ... Astronomy & Astrophysics 656, A104, 2021 | 21 | 2021 |
| The potential of Ca II K observations for solar activity and variability studies I Ermolli, T Chatzistergos, NA Krivova, SK Solanki Proceedings of the International Astronomical Union 13 (S340), 115-120, 2018 | 19 | 2018 |
| Analysis of historical solar observations and long-term changes in solar irradiance T Chatzēstergos Dissertation, Göttingen, Georg-August Universität, 2017, 2017 | 19 | 2017 |
| A note on the sunspot and prominence records made by Angelo Secchi during the period 1871–1875 VMS Carrasco, JM Nogales, JM Vaquero, T Chatzistergos, I Ermolli Journal of Space Weather and Space Climate 11, 51, 2021 | 17 | 2021 |
| Exploiting four historical Ca II K spectroheliogram archives T Chatzistergos, I Ermolli, SK Solanki, NA Krivova Coimbra solar physics meeting ground-based solar observations in the space …, 2016 | 17 | 2016 |
| Scrutinising the relationship between plage areas and sunspot areas and numbers T Chatzistergos, I Ermolli, NA Krivova, T Barata, S Carvalho, JM Malherbe Astronomy & Astrophysics 667, A167, 2022 | 16 | 2022 |
| Modeling stellar ca ii h and k emission variations. I. Effect of inclination on the s-index K Sowmya, AI Shapiro, V Witzke, NE Nèmec, T Chatzistergos, KL Yeo, ... The Astrophysical Journal 914 (1), 21, 2021 | 16 | 2021 |
| Historical solar Ca II K observations at the Rome and Catania observatories T Chatzistergos, I Ermolli, M Falco, F Giorgi, SL Guglielmino, NA Krivova, ... arXiv preprint arXiv:1902.07483, 2019 | 15 | 2019 |
Natalie KrivovaMinerva Group Leader, Max-Planck-Institut für SonnensystemforschungEmail verificata su linmpi.mpg.de