More Accurate Proper Motions in Declination than the Hipparcos Catalogue Ones by Using Optical Latitude Data

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

In 1995, Commission 19 (Earth Rotation) of IAU established the Working Group on Earth Rotation in the Hipparcos Reference Frame (WG ERHRF) to collect the optical observations of latitude and universal time variations, made during 1899.7 -- 1992.0 in line with the Earth orientation programmes (to derive Earth Orientation Parameters -- EOP). About 4.4 million observations of latitude/universal time variations made at 33 observatories were collected.
Nowadays, it is customary to correct the positions and proper motions of stars of Hipparcos Catalogue using ground-based observations of the same stars. In this PhD thesis I use the latitude observations made with several types of classical astrometric instruments: visual and floating zenith-telescopes (ZT and FZT), visual zenith tube (VZT) and photographic zenith tube (PZT), i. e. a total of 26 different instruments located at 19 observatories all over the world. I received the data from Dr. Vondrák (head of WG ERHRF).
The task was to improve the Hipparcos proper motions in declination of the observed stars. The original method was developed. It consists of removing from the instantaneous observed latitude all known effects (polar motion and some local and instrumental errors). The corrected latitudes are then used to calculate the corrections of the Hipparcos proper motions in declination by using the Least Squares Method (LSM) with the linear model. The newly obtained values of proper motions in declination are substantially more precise than those of the Hipparcos Catalogue. It is because the time interval covered by the latitude observations (tens of years) is much longer than the Hipparcos one (less than four years), and because of the great number of ground-based observations made during this interval. The calculated results were compared with ARIHIP and EOC-2 data, and I found a good agreement. The main result of the thesis is a catalogue of proper motions in declination of 2347 Hipparcos stars. Here, some results and main steps of the method are presented.

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

More Accurate Proper Motions in Declination than the Hipparcos Catalogue Ones by Using Optical Latitude Data 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 More Accurate Proper Motions in Declination than the Hipparcos Catalogue Ones by Using Optical Latitude Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and More Accurate Proper Motions in Declination than the Hipparcos Catalogue Ones by Using Optical Latitude Data will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1074741

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