Analysis of Hipparcos Measurements: Positions, Proper Motions, Parallaxes
نویسندگان
چکیده
منابع مشابه
Hipparcos Parallaxes and Proper Motions of Cepheids and Their Implications *
A summary is given of an analysis of the Hippar-cos trigonometrical parallaxes and proper motions of classical Cepheids. It is possible for the first time to derive zero-points for the period-luminosity and period-luminosity-colour relations from paral-laxes alone, avoiding the problems of less direct methods. The results imply an increase of 8 to 10 percent in the extragalactic distance scale ...
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Context. A new reduction of the astrometric data as produced by the Hipparcos mission has been published, claiming that the accuracies for nearly all stars brighter than magnitude Hp = 8 are improved, by up to a factor 4, compared to the original catalogue. As correlations between the underlying abscissa residuals have also been reduced by more than an order of magnitude to an insignificant lev...
متن کاملStellar Kinematics from Hipparcos Proper Motions
From Hipparcos proper motions, we have analyzed the local kinematics of the Milky Way from the young O-B5 stars, classical Cepheids, and the late-type K-M giants. Comparing the derived results, the kinematical discrepancies between each subset of stars have been analyzed, and the possible reasons for the kinematical di erences have been discussed.
متن کاملLocal galactic kinematics from Hipparcos proper motions
The stellar velocity field within two kiloparsecs of the solar system is investigated from the Hipparcos proper motions and parallaxes of about 20 000 single stars farther than 100 pc. The motion of the sun relative to the Local Standard of Rest and the relative systematic velocity field due to the galactic rotation are studied simultaneously for several categories of stars ranging from early t...
متن کاملGalactic Kinematics of Cepheids from Hipparcos Proper Motions
The Hipparcos proper motions of 220 galactic Cepheids, together with relevant groundbased photometry, have been analysed. The effects of galactic rotation are very clearly seen. Mean values of the Oort constants, A = 14.82 ± 0.84 km skpc, and B = −12.37 ± 0.64 km skpc, and of the angular velocity of circular rotation at the Sun, Ωo = 27.19 ± 0.87 km s kpc, are derived. Comparison of the value o...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1993
ISSN: 0074-1809
DOI: 10.1017/s0074180900172869