منابع مشابه
On the Hipparcos parallaxes of O stars
We compare the absolute visual magnitude of the majority of bright O stars in the sky as predicted from their spectral type with the absolute magnitude calculated from their apparent magnitude and the Hipparcos parallax. We find that many stars appear to be much fainter than expected, up to five magnitudes. We find no evidence for a correlation between magnitude differences and the stellar rota...
متن کاملHipparcos parallaxes and the nature of δ Scuti stars ?
Hipparcos parallaxes give new tests of the nature of δ Sct variables. For many individual stars accurate distances are now available, i.e. directly determined luminosities and radii can be used to test theoretical models. Of particular interest are the at present very unclear relations between high–amplitude δ Sct stars and the much more abundant low–amplitude δ Sct variables, and the relations...
متن کاملThe absolute magnitudes of RR Lyrae stars from HIPPARCOS parallaxes ?
Using the method of “reduced parallaxes” for the Halo RR Lyrae stars in the hipparcos catalogue we derive a zero point of 0.77 ± 0.26 mag for an assumed slope of 0.18 in the MV-[Fe/H] relation. This is 0.28 magnitude brighter than the value Fernley et al. (1998a) derived by employing the method of statistical parallax for the identical sample and using the same slope. We point out that a simila...
متن کاملsurvey on the rule of the due & hindering relying on the sheikh ansaris ideas
قاعده مقتضی و مانع در متون فقهی کم و بیش مستند احکام قرار گرفته و مورد مناقشه فقهاء و اصولیین می باشد و مشهور معتقند مقتضی و مانع، قاعده نیست بلکه یکی از مسائل ذیل استصحاب است لذا نگارنده بر آن شد تا پیرامون این قاعده پژوهش جامعی انجام دهد. به عقیده ما مقتضی دارای حیثیت مستقلی است و هر گاه می گوییم مقتضی احراز شد یعنی با ماهیت مستقل خودش محرز گشته و قطعا اقتضاء خود را خواهد داشت مانند نکاح که ...
15 صفحه اولthe effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1928
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/88.7.594