Systematic effects in trigonometric parallaxes – I. The distribution of observed parallaxes
نویسندگان
چکیده
منابع مشابه
The Lutz-Kelker bias in trigonometric parallaxes
The theoretical prediction that trigonometric parallaxes suffer from a statistical effect, has become topical again now that the results of the Hipparcos satellite have become available. This statistical effect, the so-called Lutz-Kelker bias, causes measured parallaxes to be too large. This has the implication that inferred distances, and hence inferred luminosities are too small. Published an...
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In astrophysical applications, derived quantities like distances, absolute magnitudes and velocities are used instead of the observed quantities, such as parallaxes and proper motions. As the observed values are affected by random errors and selection effects, the estimates of the astrophysical quantities can be biased if a correct statistical treatment is not used. This paper presents and disc...
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It is well known that the frequency functions of a set of quantities and of their measures are different;' if the error of measurement is comparable in magnitude to the quantity determined, they may be decidedly dissimilar. In the case of good photographic parallaxes the reported probable errors average about eight one-thousandths of a second of arc, making a dispersion of twelve. Moreover, as ...
متن کاملAbsolute measurements of trigonometric parallaxes with astrometric satellites
The concept of absolute trigonometric parallax measurements is formulated in strict mathematical terms, in connection with the widely discussed plans for a future astrometric space mission. The parallaxes determined for a large number of stars spread all over the sky are absolute if the expected error (accidental or systematic) of the zero–point, as well as other large–scale distortions are ord...
متن کاملTrigonometric Parallaxes of Massive Star Forming Regions : I . S 252 & G 232 . 6 + 1 . 0
We are conducting a large program with the NRAO Very Long Baseline Array (VLBA) to measure trigonometric parallaxes of massive star-forming regions across the Milky Way. Here we report measurement of the parallax and proper motion of methanol masers in S 252 and G232.6+1.0. The parallax of S 252 is 0.476 ± 0.006 mas (2.10 −0.026 kpc), placing it in the Perseus spiral arm. The parallax of G232.6...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1980
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/192.3.347