منابع مشابه
Luminous carbon stars in the Magellanic Clouds?
We present ground-based 3 μm spectra of obscured Asymptotic Giant Branch (AGB) stars in the Magellanic Clouds (MCs). We identify the carbon stars on the basis of the 3.1 μm absorption by HCN and C2H2 molecules. We show evidence for the existence of carbon stars up to the highest AGB luminosities (Mbol = −7 mag, for a distance modulus to the LMC of 18.7 mag). This proves that Hot Bottom Burning ...
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An experimental setup and procedure for the evaluation of selfluminous colours viewed against both dark and luminous backgrounds is presented. Physical and visual data of self-luminous colours is gathered in order to develop a Colour Appearance Model for self-luminous colours under different viewing conditions. This model is needed for the evaluation of light sources.
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We have used the Arecibo telescope to carry out an survey of 31 dark clouds in the Taurus/Perseus region for narrow absorption features in HI (λ 21cm) and OH (1667 and 1665 MHz) emission. We detected HI narrow self–absorption (HINSA) in 77% of the clouds that we observed. HINSA and OH emission, observed simultaneously are remarkably well correlated. Spectrally, they have the same nonthermal lin...
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This paper presents a simple alternative of automatic luminous control for electronic ballasts operating in selfsustained oscillating mode feeding fluorescent lamps to energy saving. The luminous flux level control is based on a signal from a lighting dependent resistor, which measures the luminous flux level. The dimming feature is obtained using switching frequency variation. Thus, the circui...
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ژورنال
عنوان ژورنال: Nature
سال: 1890
ISSN: 0028-0836,1476-4687
DOI: 10.1038/041198b0