Reconstruction of annual solar irradiance over the last three millennia D Temaj, NA Krivova, SK Solanki, IG Usoskin, T Chatzistergos arXiv preprint arXiv:2605.22399 , 2026 2026
Cyclic sunspot activity during the first millennium CE as reconstructed from radiocarbon I Usoskin, SK Solanki, NA Krivova, T Chatzistergos Astronomy & Astrophysics 708, A333 , 2026 2026 Citations: 1
Solar irradiance reconstruction over the telescopic era using a revised photospheric magnetic field model D Temaj, NA Krivova, T Chatzistergos, SK Solanki, B Hofer Astronomy & Astrophysics 708, A306 , 2026 2026 Citations: 1
Reconstructing historical solar indices for predicting past space weather events P Belbase, DM Oliveira, T Chatzistergos, G Poh, E Zesta Space Weather 24 (4), e2025SW004757 , 2026 2026
Solar Observations by Angelo Secchi: An Analysis of His Diary and Annotations in His Sunspot Drawings VMS Carrasco, I Ermolli, AJP Aparicio, T Chatzistergos The Astrophysical Journal 1000 (1), 106 , 2026 2026
Empirical flare energy limits for the largest historical sunspots NA Krivova, T Chatzistergos, M Kazachenko, E Isik arXiv preprint arXiv:2603.09474 , 2026 2026
Assessment of sunspot number cross-calibration approaches T Chatzistergos, NA Krivova, H Sundermann, IG Usoskin Astronomy & Astrophysics 699, A157 , 2025 2025 Citations: 4
Sunspot cycles for the first millennium BC reconstructed from radiocarbon I Usoskin, T Chatzistergos, SK Solanki, N Krivova, G Kovaltsov, N Brehm, ... Astronomy & Astrophysics 698, A182 , 2025 2025 Citations: 8
VizieR Online Data Catalog: 1000-year sunspot series (Usoskin+, 2025) I Usoskin, T Chatzistergos, SK Solanki, N Krivova, G Kovaltsov, N Brehm, ... VizieR Online Data Catalog 369, J/A+ A/698/A182 , 2025 2025
Structure and dynamics of the Sun’s interior revealed by the Helioseismic and Magnetic Imager AG Kosovichev, S Basu, Y Bekki, JC Buitrago-Casas, T Chatzistergos, ... Solar Physics 300 (5), 70 , 2025 2025 Citations: 16
Revisiting the SATIRE-S irradiance reconstruction: Heritage of Mt Wilson magnetograms and Ca II K observations T Chatzistergos, NA Krivova, SK Solanki, K Leng Yeo Astronomy & Astrophysics 696, A204 , 2025 2025 Citations: 5
Solar forcing for CMIP7 B Funke, T Dudok de Wit, M Haberreiter, D Marsh, I Ermolli, D Kinnison, ... EGU General Assembly Conference Abstracts, EGU25-15908 , 2025 2025
Solar forcing for CMIP7: making of future scenarios T Dudok de Wit, B Funke, M Haberreiter, D Marsh, I Ermolli, D Kinnison, ... EGU General Assembly Conference Abstracts, EGU25-17597 , 2025 2025
Ca ii K Polar Network Index of the Sun: A Proxy for Historical Polar Magnetic Field DK Mishra, BK Jha, T Chatzistergos, I Ermolli, D Banerjee, LA Upton, ... The Astrophysical Journal 982 (2), 78 , 2025 2025 Citations: 8
Detectability of Solar Rotation Period across Various Wavelengths V Vasilyev, T Reinhold, AI Shapiro, T Chatzistergos, N Krivova, ... The Astrophysical Journal Letters 980 (2), L32 , 2025 2025 Citations: 2
Solar Variability in the Mg ii h and k Lines K Sowmya, M Snow, AI Shapiro, NA Krivova, T Chatzistergos, SK Solanki The Astrophysical Journal 980 (2), 173 , 2025 2025 Citations: 2
Estimation of Polar Magnetic Fields using Ca II K Polar Network as a Proxy DK Mishra, BK Jha, T Chatzistergos, I Ermolli, D Banerjee, MS Khan arXiv preprint arXiv:2502.07481 , 2025 2025
Estimation of Polar Magnetic Fields using Ca II K Polar Network as a Proxy D Kirti Mishra, BK Jha, T Chatzistergos, I Ermolli, D Banerjee, ... arXiv e-prints, arXiv: 2502.07481 , 2025 2025
Ca II K Polar Network Index of the Sun: A Proxy for Historical Polar Magnetic Field D Kirti Mishra, BK Jha, T Chatzistergos, I Ermolli, D Banerjee, LA Upton, ... arXiv e-prints, arXiv: 2502.01371 , 2025 2025
Solar variability in the mg ii h and k lines M Snow, S Krishnamurthy, T Chatzistergos Institute of Physics , 2025 2025
MOST CITED SCHOLAR PUBLICATIONS
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 2017 Citations: 110
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 2023 Citations: 92
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 2019 Citations: 61
Long-term changes in solar activity and irradiance T Chatzistergos, NA Krivova, KL Yeo Journal of Atmospheric and Solar-Terrestrial Physics 252, 106150 , 2023 2023 Citations: 60
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 2020 Citations: 59
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 2018 Citations: 53
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 2019 Citations: 47
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 2022 Citations: 40
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 2021 Citations: 35
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 2021 Citations: 32
The extreme space weather event of 1872 February: sunspots, magnetic disturbance, and auroral displays H Hayakawa, EW Cliver, F Clette, Y Ebihara, S Toriumi, I Ermolli, ... The Astrophysical Journal 959 (1), 23 , 2023 2023 Citations: 31
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 2016 Citations: 30
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 2019 Citations: 29
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 2022 Citations: 28
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 2020 Citations: 28
Understanding the secular variability of solar irradiance: the potential of Ca II K observations T Chatzistergos, NA Krivova, I Ermolli Journal of Space Weather and Space Climate 14, 9 , 2024 2024 Citations: 24
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 2021 Citations: 23
Analysis of historical solar observations and long-term changes in solar irradiance T Chatzistergos 2017 Citations: 23
Differential Rotation of the Solar Chromosphere: A Century-long Perspective from Kodaikanal Solar Observatory Ca ii K Data DK Mishra, S Routh, BK Jha, T Chatzistergos, J Basu, S Chatterjee, ... The Astrophysical Journal 961 (1), 40 , 2024 2024 Citations: 21
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 2018 Citations: 21
