31 citations · 55 across the 6 of their papers we have counts for
6 papers
An Explanation of the Vaughan - Preston Gap
Peter Foukal
A plot of the calcium emission versus color of late type stars exhibits a reduced population or gap at intermediate activity, somewhat higher than that of the Sun. We suggest that…
Reddened Dimming of Boyajian's Star Supports Internal Storage of Its "Missing" Flux
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 pa…
An explanation of the missing flux from Boyajian's mysterious star
Peter Foukal
A previously unremarked star in the constellation Cygnus has,in the past year,become known as the most mysterious star in our Galaxy.Boyajian's star exhibits puzzling episodes of s…
A study of solar photospheric temperature gradient variation using limb darkening measurements
Serena Criscuoli, Peter Foukal
The variation in area of quiet magnetic network measured over the sunspot cycle should modulate the spatially averaged photospheric temperature gradient, since temperature declines…
Dimming of the Mid-20th Century Sun
Peter Foukal
Advances in understanding of the white light faculae measured at the Royal Greenwich Observatory from 1874 to 1976 suggest that they offer a more direct measure of solar brightenin…
Dimming of the 17th Century Sun
Peter Foukal, Ada Ortiz, Roald Schnerr
Reconstructions of total solar irradiance (TSI) rely mainly on linear relations between TSI variation and indices of facular area. When these are extrapolated to the prolonged 15th…