Modern Photometry
نویسندگان
چکیده
منابع مشابه
Conjugateplane photometry: reducing scintillation in groundbased photometry
High-precision fast photometry from ground-based observatories is a challenge due to intensity fluctuations (scintillation) produced by the Earth’s atmosphere. Here we describe a method to reduce the effects of scintillation by a combination of pupil reconjugation and calibration using a comparison star. Because scintillation is produced by high-altitude turbulence, the range of angles over whi...
متن کاملRecent MOST space photometry
The Microvariability and Oscillations of STars (MOST) photometric satellite has already undertaken more than 64 primary campaigns which include some clusters and has obtained observations of >850 secondary stars of which ∼180 are variable. More than half of the variables pulsate, with the majority being of B-type. Since 2006 January, MOST has operated with only a single CCD for both guiding and...
متن کاملHeterochromatic modulation photometry.
Heterochromatic modulation photometry is a method for obtaining equiluminance for a pair of heterochromatic lights presented in temporal alternation. A series of fixed standard luminance/test luminance ratios are presented, and at each ratio the modulation depth of the pair is reduced in tandem until the observer reports that flicker disappears. The data can be described by a luminance contrast...
متن کاملCircadian field photometry
λ wavelength λmax peak wavelength µW/cm 2 microwatt per square centimeter A/Hz ½ amperes per root hertz A/W amperes per watt acv circadian action factor Ap pupil area Ar area of the image at the retina As source area B noise bandwidth [Hz] B(λ) action spectra for blue light hazard (ICNIRP) B(λ) " biological/circadian " action spectra b-lx blue-lx, unit for blue-colored illuminance BYλ hypotheti...
متن کاملPhotometry of Abell 2390
We present the results of a search for strong Hα emission line galaxies (rest frame equivalent widths greater than 50Å) in the z ≈ 0.23 cluster Abell 2390. The survey contains 1189 galaxies over 270 ⊓⊔′, and is 50% complete at Mr ≈ −17.5 + 5 log h. The fraction of galaxies in which Hα is detected at the 2σ level rises from 0.0 in the central regions (excluding the cD galaxy) to 12.5±8% at R200....
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ژورنال
عنوان ژورنال: Nature
سال: 1954
ISSN: 0028-0836,1476-4687
DOI: 10.1038/173697b0