J/other/Ser/177.109 Corrections to HIP proper motions (Damljanovic+, 2008)
Corrections to the Hipparcos proper motions in declination for 807 stars.
Damljanovic G., Pejovic N.
<Serbian Astron. Journal, 177, 109-113 (2008)>
=2008SerAJ.177..109D 2008SerAJ.177..109D
ADC_Keywords: Positional data ; Proper motions
Keywords: astrometry - reference systems
Abstract:
We used the data on latitude variations obtained from observations
with 10 classical photographic zenith tubes (PZT) in order to improve
the Hipparcos proper motions in declinations µδ for 807
stars. Part of observing programmes, carried out during the last
century for the purpose of studying the Earth's rotation, were
realized by using PZT instruments. These observations were performed
within in the intervals (tens of years) much longer than that of the
Hipparcos mission (less than 4 years). In addition, the annual number
of observations for every PZT- programme star is several hundreds on
the average. Though the accuracy of the star coordinates in the
Hipparcos Catalogue is by two orders of magnitude better than that of
the star coordinates from the PZT observations, the large number of
observations performed a much longer time interval makes it possible
to correct the Hipparcos proper motions and to improve their accuracy
with respect to the accuracy given in the Hipparcos Catalogue. Long
term examinations of latitude and time variations were used to form
the Earth Orientation Catalogue (EOC-2), aimed at a more accurate
determination of positions and proper motions for the stars included.
Our method of calculating the corrections of the proper motions in
declination from the latitude variations is different from the method
used in obtaining the EOC-2 Catalogue. Comparing the results we have
established a good agreement between our µδ and the EOC-2
ones for the star sample used in the present paper.
Description:
Here we use the results of latitude observations made with PZT
instruments over a few decades together with the Hipparcos Catalogue
data, in order to obtain proper motions in declination more accurate
than the Hipparcos ones for 807 stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 60 807 The values of pmDE and e_pmDE for 807 stars:
ours, EOC-2 and Hipparcos ones
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/A+A/463/783 : Combined astrometric catalogue EOC-3 (Vondrak+, 2007)
J/A+A/509/A3 : Earth Orientation Catalog 4 (EOC-4) (Vondrak+, 2010)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP HIP number (Cat. I/239)
9- 11 I3 --- Np Number of points
14- 20 F7.2 mas/yr pmDE Proper motion along Declination
23- 26 F4.2 mas/yr e_pmDE rms uncertainty on pmDE
29- 35 F7.2 mas/yr pmDE(E) EOC-2 proper motion along Declination
38- 41 F4.2 mas/yr e_pmDE(E) rms uncertainty on pmDEE
44- 50 F7.2 mas/yr pmDE(H) HIP proper motion along Declination
53- 56 F4.2 mas/yr e_pmDE(H) rms uncertainty on pmDEH
60 A1 --- Obs [12-] Observatory code (1)
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Note (1): Observatory code as follows:
1 = star is common to Washington and Mizusawa
2 = star is common to Mount Stromlo and Punta Indio
- = star is observed at only one observatory
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 11-Jan-2011