The ∆a photometric system
The ∆a photometric system

Author: Ernst Paunzen

Publisher: Cuvillier Verlag

Published: 2020-10-13

Total Pages: 248

ISBN-13: 3736962835

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This book describes the characteristics and applications of the Δa photometric system, which measures the stellar flux at around 520 nm. Since its introduction in 1976 by Hans-Michael Maitzen, the Δa system has not only been successfully applied to the classical chemically peculiar stars of the upper main sequence, but also to galactic and extragalactic star clusters. New possible applications for studying galaxies, quasars and other astrophysical objects of interest are discussed.

Broadband UV-, VIS-, and IR-Radiometric, Photometric, Color, and Temperature Measurements
Broadband UV-, VIS-, and IR-Radiometric, Photometric, Color, and Temperature Measurements

Author: George P. Eppeldauer

Publisher: Cambridge Scholars Publishing

Published: 2021-04-07

Total Pages: 234

ISBN-13: 1527568091

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In most field applications, broadband measurements are used where the spectral product of the source distribution and the meter’s spectral responsivity is measured. This book discusses detector-based radiometric, photometric, color, radiation-temperature, digital imaging-system, and LED measurements. It also shows that, while in photometry, the meter’s standard response covers only the visible, broadband measurements in the UV and IR require different standards. To avoid large errors when using a traditional detector- or source-standard, where the differences in the source distributions and in the meter’s responsivities produce large errors, the signal measurement procedure itself must be standardized. To satisfy the steps of the procedure, selected or properly designed meters should be used. This book is a guide to performing uniform broadband measurements with low uncertainty.

Astronomical Photometry
Astronomical Photometry

Author: Eugene F. Milone

Publisher: Springer Science & Business Media

Published: 2011-04-06

Total Pages: 226

ISBN-13: 1441980504

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This book will bring together experts in the field of astronomical photometry to discuss how their subfields provide the precision and accuracy in astronomical energy flux measurements that are needed to permit tests of astrophysical theories. Differential photometers and photometry, improvements in infrared precision, the improvements in precision and accuracy of CCD photometry, the absolute calibration of flux, the development of the Johnson UBVRI photometric system and other passband systems to measure and precisely classify specific types of stars and astrophysical quantities, and the current capabilities of spectrophotometry, and polarimetry to provide precise and accurate data, will all be discussed in this volume. The discussion of `differential’ or `two-star’ photometers will include those developed for planetary as well as stellar photometry and will range from the Princeton polarizing photometer through the pioneering work of Walraven to the differential photometers designed to measure the ashen light of Venus and to counter the effects of aurorae at high latitude sites; the last to be discussed will be the Rapid Alternate Detection System (RADS) developed at the University of Calgary in the 1980s.