HIPPARCOS Data Distribution to the Community
نویسندگان
چکیده
منابع مشابه
modeling loss data by phase-type distribution
بیمه گران همیشه بابت خسارات بیمه نامه های تحت پوشش خود نگران بوده و روش هایی را جستجو می کنند که بتوانند داده های خسارات گذشته را با هدف اتخاذ یک تصمیم بهینه مدل بندی نمایند. در این پژوهش توزیع های فیزتایپ در مدل بندی داده های خسارات معرفی شده که شامل استنباط آماری مربوطه و استفاده از الگوریتم em در برآورد پارامترهای توزیع است. در پایان امکان استفاده از این توزیع در مدل بندی داده های گروه بندی ...
The Hipparcos mission: photometric data
An overview of the Hipparcos and Tycho photometric data is presented, with reference to the main aspects of the data reductions and the overall quality and quantity of the results. The data have been presented in three forms: as mean values in the astrometric catalogues, as epoch photometry, and as interpreted results of the variability analysis, which is also briefly described.
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We analyze the K band luminosities of a sample of galactic long-period variables using parallaxes measured by the Hipparcos mission. The parallaxes are in most cases re-computed from the Hipparcos Intermediate Astrometric Data using improved astrometric fits and chromaticity corrections. The K band magnitudes are taken from the literature and from measurements by COBE, and are corrected for int...
متن کاملThe velocity distribution of nearby stars from Hipparcos data I. The significance of the moving groups
We present a three-dimensional reconstruction of the velocity distribution of nearby stars (. 100 pc) using a maximum likelihood density estimation technique applied to the two-dimensional tangential velocities of stars. The underlying distribution is modeled as a mixture of Gaussian components. The algorithm reconstructs the error-deconvolved distribution function, even when the individual sta...
متن کاملThe Distribution of Nearby Stars in Velocity Space Inferred from Hipparcos Data
The velocity distribution f(v) of nearby stars is estimated, via a maximum-likelihood algorithm, from the positions and tangential velocities of a kinematically unbiased sample of 14 369 stars observed by the HIPPARCOS satellite. f shows rich structure in the radial and azimuthal motions, vR and vφ, but not in the vertical velocity, vz: there are four prominent and many smaller maxima, many of ...
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ژورنال
عنوان ژورنال: Highlights of Astronomy
سال: 1992
ISSN: 1539-2996
DOI: 10.1017/s1539299600009461