The Earth Orientation Catalog 4 . An optical reference frame for monitoring Earth's orientation in the 20th century

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

1

Astrometry, Reference Systems, Catalogs

Scientific paper

Context. The astrometric ground-based observations of latitude/universal time variations, covering the interval 1899.7-2003.0, were used in combination with Hipparcos/Tycho positions and some older ground-based catalogs to construct a family of catalogs, tailored to long-term Earth-rotation studies. These catalogs, called Earth Orientation Catalogs (EOC-1 through EOC-3) yielded more accurate proper motions than the original Hipparcos Catalogue, and its latest version, EOC-3, even periodic motions for a large portion of the stars. Aims: It appeared that more stars than are contained in EOC-3 are double or multiple and that a better procedure can be used to improve the periodic terms, reflecting the orbital motions of the stars observed in the programs of monitoring Earth orientation. Methods: We used about 4.5 million observations of latitude/universal time variations at 33 observatories all over the world, and combined them with the catalogs ARIHIP, TYCHO-2, etc. to obtain the Earth Orientation Catalog (EOC-4). These observations are identical to those used to construct the previous version, EOC-3. Spectral analysis of ground-based data and comparison with the USNO Sixth Catalog of Orbits of Visual Binary Stars was used to discover which of the observed objects display periodic motions. The corresponding amplitudes and phases were then estimated in one-step least-squares solution, together with positions and proper motions. Unlike in EOC-3, where annual averages were used, we use here the individual nightly observations. Results: The fourth version of the catalog, EOC-4, contains 4418 different objects (i.e., stars, components of double stars, photocenters), out of which 599 have significant orbital motions. The catalog will eventually be used for new determination of the Earth orientation parameters during the twentieth century.
Table 1 (EOC4 catalog) is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/509/A3

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The Earth Orientation Catalog 4 . An optical reference frame for monitoring Earth's orientation in the 20th century does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Earth Orientation Catalog 4 . An optical reference frame for monitoring Earth's orientation in the 20th century, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Earth Orientation Catalog 4 . An optical reference frame for monitoring Earth's orientation in the 20th century will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-960694

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.