Zobrazeno 1 - 10
of 26
pro vyhledávání: '"T. Willamo"'
Autor:
A. Ibragimov, T. Willamo, Sergey Koldobskiy, Agnieszka Gil, Gennady A. Kovaltsov, Inna Usoskina, Ilya Usoskin
Funding Information: This work was partly supported by the Academy of Finland (project 321882 ESPERA). Publisher Copyright: © Copyright owned by the author(s). The main detector to provide data to study highly energetic (above ≈400 MeV) solar part
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c1f85235f6128e82430d52efba8133ec
http://hdl.handle.net/10138/355994
http://hdl.handle.net/10138/355994
Autor:
J. Lehtinen, Maarit J. Käpylä, Mariangela Viviani, Jörn Warnecke, Thomas Hackman, T. Willamo, N. Olspert
Publikováno v:
Astronomy & Astrophysics
Magnetic activity cycles are an important phenomenon in both the Sun and other stars. The shape of the solar cycle is commonly characterised by a fast rise and a slower decline, but not much attention has been paid to the shape of cycles in other sta
Autor:
J. J. Lehtinen, M. J. Käpylä, T. Hackman, O. Kochukhov, T. Willamo, S. C. Marsden, S. V. Jeffers, G. W. Henry, L. Jetsu
Previous studies have related surface temperature maps, obtained with the Doppler imaging (DI) technique, of LQ Hya with long-term photometry. We compare surface magnetic field maps, obtained with the Zeeman Doppler imaging (ZDI) technique, with cont
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7de804528fc2c6fe0eb4e8bd0f6549ab
http://arxiv.org/abs/1909.11028
http://arxiv.org/abs/1909.11028
Autor:
Nikolai Piskunov, Maarit J. Käpylä, T. Willamo, Thomas Hackman, Oleg Kochukhov, J. Lehtinen, Iya Ilyin
Context. Studying the spots of late-type stars is crucial for distinguishing between the various proposed dynamo mechanisms believed to be the main cause of starspot activity. For this research it is important to collect observation time series that
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::69943d68d74aa5bfb91794ec526dfdc8
http://arxiv.org/abs/1812.02013
http://arxiv.org/abs/1812.02013
Autor:
G. A. Kovaltsov, Sergey Koldobskiy, Ilya Usoskin, T. Willamo, Agnieszka Gil, I. Usoskina, A. Ibragimov
Publikováno v:
Astronomy & Astrophysics. 640:A17
Aims.Continuous measurements of ground-based neutron monitors (NMs) form the main data source for studying high-energy high-intensity solar energetic particle (SEP) events that are called ground-level enhancements (GLEs). All available data are colle
The method of active day fraction (ADF) was proposed recently to calibrate different solar observers to the standard observational conditions. The result of the calibration may depend on the overall level of solar activity during the observational pe
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::acb1740589bcb2014ceb71274d768cf8
http://arxiv.org/abs/1803.10501
http://arxiv.org/abs/1803.10501
Autor:
Maarit J. Käpylä, Gregory W. Henry, Oleg Kochukhov, T. Willamo, Ilya Ilyin, J. Lehtinen, Nikolai Piskunov, Lauri Jetsu, Thomas Hackman
Starspots are important manifestations of stellar magnetic activity. By studying their behaviour in young solar analogues, we can unravel the properties of their magnetic cycles. This gives crucial information of the underlying dynamo process. Compar
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b812fe2f6f3513d6ef6306ebd5465e88
Autor:
Agnieszka Gil, T. Willamo, Gennady A. Kovaltsov, V. V. Mikhailov, A. G. Mayorov, Ilya Usoskin, Eleanna Asvestari
Publikováno v:
Scopus-Elsevier
Ground Level Enhancements (GLEs) recorded by neutron monitor detectors are characterized by a variety of energy spectra of solar energetic particles (SEP), which vary between soft (as in August 1972) and hard (February 1956) ones. The aim of this wor
Sunspot number series are composed from observations of hundreds of different observers that requires careful normalization of the observers to the standard conditions. Here we present a new normalized series of the number of sunspot groups for the p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3f72cc3c6f8398ae8ebebb06d7aed9c6
http://urn.fi/urn:nbn:fi-fe201705176580
http://urn.fi/urn:nbn:fi-fe201705176580
Autor:
T. Willamo, Eleanna Asvestari, Gennady A. Kovaltsov, Agnieszka Gil, Ilya Usoskin, V. V. Mikhailov, A. G. Mayorov
Nearly 70 Ground Level Enhancements (GLEs) of cosmic rays have been recorded by the worldwide neutron monitor network since the 1950s depicting a big variety of energy spectra of solar energetic particles (SEP). Here we studied a statistical relation
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b7ea89ff1e8c8c1987ee1eb88fbe64a7