Zobrazeno 1 - 10
of 83
pro vyhledávání: '"Peter Foukal"'
Autor:
Peter Foukal
Publikováno v:
Journal of Astronomical History and Heritage. 24:1059-1062
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4fb699a39189abc545d09f1cf7f48c72
https://doi.org/10.3724/sp.j.1440-2807.2021.04.12
https://doi.org/10.3724/sp.j.1440-2807.2021.04.12
Autor:
Peter Foukal
Publikováno v:
Physics Today. 75:11-12
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::42fb0b9d8ae4540c2c398b7a517af190
https://doi.org/10.1063/pt.3.5049
https://doi.org/10.1063/pt.3.5049
Publikováno v:
Journal of Astronomical History and Heritage. 24:1057-1058
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9cd7eba275dc8ff648a3029a5cb142f6
https://doi.org/10.3724/sp.j.1440-2807.2021.04.11
https://doi.org/10.3724/sp.j.1440-2807.2021.04.11
Autor:
Peter Foukal
A question posed by a charming Countess sets Philip Frobisher, a Harvard astronomer, on a quest to make a more important contribution to science and society. Anna Grad, a talented Harvard student, interns in Washington for a Senator known for his opp
Autor:
Peter Foukal
Two recent short term dimmings of KIC 8462852 (Boyajian's Star) exhibit clear reddening in the B, r' and i' photometric passbands. We show that the intensity ratios of the three pass bands agree well with cooling of an approximately 6800 K black body
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef09b5b067190df453113d1646dccf0b
Autor:
Peter Foukal
Publikováno v:
Solar Physics. 289:1517-1529
Several studies have shown that the sunspot areas recorded by the Royal Greenwich Observatory (RGO) between 1874 – 1976 are about 40 – 50 % larger than those measured by the NOAA/USAF Solar Observing Optical Network (SOON) since 1966. We show her
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::172562932dbca40a6d977cdb4a404a23
https://doi.org/10.1007/s11207-013-0425-2
https://doi.org/10.1007/s11207-013-0425-2
Autor:
Peter Foukal
Publikováno v:
Solar Physics. 279:365-381
We compare total solar irradiance (TSI) and ultraviolet (Fuv) irradiance variation reconstructed using Ca K facular areas since 1915, with previous values based on less di- rect proxies. Our annual means for 1925 - 1945 reach values 30 - 50 % higher
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::abc7ee2280c138e77db4db424304aeb1
https://doi.org/10.1007/s11207-012-0017-6
https://doi.org/10.1007/s11207-012-0017-6
Autor:
Peter Foukal, Pietro N. Bernasconi
Publikováno v:
Solar Physics. 248:1-15
Variations in total solar irradiance (TSI) correlate well with changes in projected area of photospheric magnetic flux tubes associated with dark sunspots and bright faculae in active regions and network. This correlation does not, however, rule out
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2d754b566b72ba8d3e38274af3bb1447
https://doi.org/10.1007/s11207-008-9134-7
https://doi.org/10.1007/s11207-008-9134-7
Autor:
Peter Foukal
Area changes of photospheric faculae associated with magnetic active regions are responsible for the bright contribution to variation in total solar irradiance (TSI). Yet, the 102-year white light (WL) facular record measured by the Royal Greenwich O
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a3ff2138a083a75735ac908706245cc7
http://arxiv.org/abs/1505.01040
http://arxiv.org/abs/1505.01040
Publikováno v:
Nature. 443:161-166
Variations in the Sun's total energy output (luminosity) are caused by changing dark (sunspot) and bright structures on the solar disk during the 11-year sunspot cycle. The variations measured from spacecraft since 1978 are too small to have contribu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4a555f8bf48a0e8231158f7604dce788
https://doi.org/10.1038/nature05072
https://doi.org/10.1038/nature05072