scholarly journals The Tautenburg Schmidt Telescope and Galactic Proper Motion Studies

1995 ◽  
Vol 148 ◽  
pp. 267-270 ◽  
Author(s):  
E. Schilbach ◽  
R.-D. Scholz ◽  
S. Hirte
Keyword(s):  
Proper Motion ◽  
Galactic Plane ◽  
Proper Motions ◽  
Schmidt Telescope ◽  
Automatic Measuring ◽  
Wide Range ◽  
Motion Studies ◽  
Photographic Photometry ◽  
Better Than

AbstractThe combination of Tautenburg plates and automatic measuring machines provides a powerful tool to obtain photometry and proper motions of a great number of stars for statistical investigations of our Galaxy. Photographic photometry with an accuracy of about 0.07 mag can be obtained provided two plates of the same colour and a sufficient number of photometric standards are available. With two plate pairs and a 20 years baseline, a proper motion accuracy better than 4 mas/year can be achieved for stars over a wide range of magnitudes. Outside the Galactic plane proper motions are determined with respect to hundreds of background galaxies.

scholarly journals Wide-Field Stellar Statistics from Tautenburg Schmidt Plates

1994 ◽  
Vol 161 ◽  
pp. 441-443
Author(s):  
E. Schilbach ◽  
R.-D. Scholz ◽  
S. Hirte
Keyword(s):  
Galactic Plane ◽  
Focal Length ◽  
Photometric Data ◽  
Wide Field ◽  
Plate Bending ◽  
Proper Motions ◽  
Schmidt Telescope ◽  
Positional Accuracy ◽  
Wide Range ◽  
Enormous Amount

For a detailed investigation of the kinematics of our Galaxy we need accurate proper motions and photometric data of stars over a wide range of magnitudes. The proper motions have to be obtained with respect to an extragalactic, i.e. nonrotating reference system. The best way to determine absolute proper motions of a great number of stars for further statistical analysis is to use the enormous amount of information stored on photographic plates taken with large Schmidt telescopes within the last decades. Since automated measuring machines have become available it is no longer a problem to extract this information from a Schmidt plate. Large Schmidt plates cover a sky area of more than 30 square degrees with usually thousands of stars and hundreds of galaxies per square degree outside the galactic plane. With the Tautenburg Schmidt telescope (134/200/400) more than 8000 plates have been taken in selected Northern sky areas since it was mounted in 1960. A 24 cm × 24 cm Tautenburg plate covers a field of about 10 square degrees, and a 20 minute exposure of a B plate has a limiting magnitude of 19 to 21. In comparison to other large Schmidt telescopes the plate bending is reduced to a minimum due to the four metre focal length and the use of relatively small plates. Therefore irregular positional shifts of the emulsion caused by the rebending after the exposure are of less influence. The large focal length leads to a plate scale of 51 arcsec/mm providing a relatively high positional accuracy.

scholarly journals Proper Motions with respect to Galaxies (Invited Paper)

1974 ◽  
Vol 61 ◽  
pp. 193-200
Author(s):  
A. N. Deutsch ◽  
A. R. Klemola
Keyword(s):  
Southern Hemisphere ◽  
Proper Motion ◽  
Second Phase ◽  
Proper Motions ◽  
Schmidt Telescope ◽  
Complete Coverage ◽  
Physical Interest ◽  
Zone Of Avoidance

At Lick the second phase of the proper motion program is in progress. In addition to generally selected stars, as was done for the first phase, so far over 30000 stars of special types of astro-physical interest and about 29000 AGK3 stars have been selected for measurement.In accordance with the Pulkovo program, second-epoch photography with galaxies is being continued at Pulkovo, Moscow and Tashkent, and proper motions with reference to galaxies are derived.Analyses of proper motions at Pulkovo and Lick show agreement in some instances and disagreement in others. The same applies to comparisons with fundamental catalogues. The analyses suffer to some extent from absence of proper motions in the zone of avoidance and in the southern part of the sky.In the southern hemisphere, first-epoch photography of 164 fields with galaxies has been completed using the Maksutov double-meniscus telescope at Cerro El Roble in Chile, and a complete coverage of the sky has been started with the same telescope; this work is being done jointly by the Soviet and Chilean astronomers. On the Yale-Columbia southern program, the first-epoch photography is nearly completed with the double astrograph at Leoncito in Argentina. There are plans at Lohrmann Institute, Dresden, to take photographs with the 2-m Schmidt telescope at Tautenburg, thus providing first-epoch plates for proper motions with reference to galaxies.

Photoelectric Vilnius Photometry of Stars in the Mega Proper Motion Field KA 10

2003 ◽  
Vol 12 (3) ◽  
Author(s):  
S. Bartašiutė
Keyword(s):  
Proper Motion ◽  
Galactic Plane ◽  
Galactic Disk ◽  
Chemical Properties ◽  
Absolute Magnitude ◽  
Motion Field ◽  
Proper Motions ◽  
Velocity Measurements ◽  
Color Excess ◽  
And Chemical Properties

AbstractPhotoelectric seven-color photometry in the Vilnius medium-band, system is obtained for 87 stars down to V≃13.0 in the Kiev proper motion field KA10 [l = 137°, b = -59°]. The size of the field is 1.4 square degrees. For each star, photometric spectral type, absolute magnitude, metallicity, and color excess due to interstellar reddening have been determined. These data, together with previous Vilnius photometry obtained in other seven KA fields at high Galactic latitudes, will be combined with radial-velocity measurements and available proper motions to yield space velocities and to investigate kinematical and chemical properties of the Galactic disk in the direction perpendicular to the Galactic plane.

scholarly journals The Lick Northern Proper Motion Program

1995 ◽  
Vol 166 ◽  
pp. 45-48 ◽  
Author(s):  
A.R. Klemola ◽  
R.B. Hanson ◽  
B.F. Jones
Keyword(s):  
Proper Motion ◽  
Milky Way ◽  
Proper Motions ◽  
Photographic Photometry

The Lick Northern Proper Motion (NPM) Program will provide absolute proper motions (referred to faint galaxies), equatorial coordinates, and two-color photographic photometry for some 300,000 stars with 8 < B < 18 covering the 70% of the sky north of declination −23°. Part 1 of the NPM program (NPM1), recently completed, covers the 72% of the northern sky (899 of 1,246 fields) outside the Milky Way. Two catalogs result from NPM1: The NPM1 Catalog (Klemola et al. 1993a, Hanson 1993a) contains 149,000 stars. The NPM1 Reference Galaxy List (Klemola et al. 1993b, Hanson 1993b) contains 50,000 faint galaxies. Klemola et al. (1987, 1994, 1995) describe the NPM program. Hanson et al. (1994) describe the NPM1 Catalogs.

scholarly journals Absolute proper motions of water masers in NGC 281 measured with VERA

2007 ◽  
Vol 3 (S242) ◽  
pp. 170-171
Author(s):  
Mayumi Sato ◽  
Tomoya Hirota ◽  
Mareki Honma ◽  
Hideyuki Kobayashi ◽  
Keyword(s):  
Vertical Velocity ◽  
Proper Motion ◽  
Molecular Cloud ◽  
Direct Evidence ◽  
Galactic Plane ◽  
Proper Motions ◽  
Supernova Explosions ◽  
Motion Measurements ◽  
Water Masers

AbstractWe report on absolute proper-motion measurements of H2O maser features in the NGC 281 West molecular cloud, located ~320 pc above the Galactic plane and associated with an HI loop extending from the Galactic plane. We conducted six-epoch phase-referencing observations of the maser source with VERA (VLBI Exploration of Radio Astrometry) over six months since May 2006. The H2O maser features are found to be systematically moving toward the southwest and further away from the Galactic plane with a vertical velocity of ~20–30 km s−1 at its estimated distance of 2.2–3.5 kpc. Our new results provide the most direct evidence that the gas in the NGC 281 region was blown out from the Galactic plane, most likely in a superbubble driven by multiple or sequential supernova explosions in the Galactic plane.

scholarly journals Measurement of the absolute proper motions of the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 491-492 ◽  
Author(s):  
H.-J. Tucholke ◽  
M. Hiesgen
Keyword(s):  
Proper Motion ◽  
Independent Study ◽  
Magellanic Clouds ◽  
Proper Motions ◽  
Schmidt Telescope ◽  
Large Numbers ◽  
The Absolute

Currently, we are measuring the absolute proper motions of the Magellanic Clouds relative to background galaxies, using plates taken with the ESO Schmidt Telescope. In spite of the small epoch difference of about 15 years, an accuracy of 0.5-1.0 milliarcsecs (mas) may be achieved using large numbers of stars and galaxies. Measurement and reduction procedures are presented; a preliminary solution for the absolute proper motion of the LMC from the measurements of three plates gives a result similar to the independent study of Jones et al. (1989).

scholarly journals New ultracool dwarf neighbours within 20 pc from Gaia DR2

2020 ◽  
Vol 637 ◽  
pp. A45
Author(s):  
R.-D. Scholz
Keyword(s):  
Proper Motion ◽  
Visual Inspection ◽  
Near Infrared ◽  
Galactic Plane ◽  
Proper Motions ◽  
Magnitude Diagram ◽  
Motion Measurements ◽  
Moving Groups ◽  
Absolute Magnitudes ◽  
Gaia Dr2

Aims. The Gaia data release 2 (DR2) contains > 6000 objects with parallaxes (Plx + 3 × e_Plx) > 50 mas, placing them within 20 pc from the Sun. Because the expected numbers based on extrapolating the well-known 10 pc census are much lower, nearby Gaia stars need a quality assessment. The 20 pc sample of white dwarfs (WDs) has been verified and completed with Gaia DR2. We here confirm and complete the 20 pc sample of ultracool dwarfs (UCDs) with spectral types ≳M7 and given Gaia DR2 parallaxes. Methods. Dividing the Gaia DR2 20 pc sample into subsamples of various astrometric and photometric quality, we studied their distribution on the sky, in the MG versus G − RP colour-magnitude diagram (CMD), and as a function of G magnitude and total proper motion. After excluding 139 known WDs and 263 known UCDs from the CMD, we checked all remaining ≈3500 candidates with MG >  14 mag (used to define UCDs in this study) for the correctness of their Gaia DR2 proper motions by visual inspection of finder charts, comparison with proper motion catalogues, and comparison with our own proper motion measurements. For confirmed UCD candidates we estimated spectral types photometrically using Gaia and near-infrared absolute magnitudes and colours. Results. We failed to confirm new WDs, but found 50 new UCD candidates that are not mentioned in three previous studies using Gaia DR2. They have relatively small proper motions and low tangential velocities and are concentrated towards the Galactic plane. Half of them have spectral types in SIMBAD and/or previous non-Gaia distance estimates that placed them already within 20 pc. For 20 of the 50 objects, we estimated photometric spectral types of M6−M6.5, slightly below the classical UCD spectral type limit. However, seven L4.5−L6.5, four L0−L1, five M8.5−M9.5, and three M7−M8 dwarfs can be considered as completely new UCDs discoveries within 20 pc based on Gaia DR2. Four M6.5 and two L4.5 dwarfs have high membership probabilities (64%−99%) in the ARGUS, AB Doradus, or Carina Near young moving groups.

scholarly journals Automated Proper Motion Survey: Data Reduction and Initial System Performance

1970 ◽  
Vol 7 ◽  
pp. 26-47 ◽  
Author(s):  
A. E. La Bonte
Keyword(s):  
Data Reduction ◽  
Proper Motion ◽  
System Performance ◽  
Processing Time ◽  
The Other ◽  
Photographic Emulsion ◽  
Proper Motions ◽  
Plate Material ◽  
Schmidt Telescope ◽  
Plate Center

The Automated Proper Motion Survey (APMS) has three broad goals-accuracy, completeness, and efficiency in the discovery and measurement of stellar proper motions on pairs of red-sensitive photographic star plates taken with the forty-eight inch Schmidt telescope. The specific range of motions sought is from 0.1 to 2.5 seconds-of-arc per year. The lower limit of 0.1 arc sec/year is consistent with the inherent uncertainties in the photographic emulsion and the typical epoch difference between plate exposures. At the opposite end of the scale, extension of the search radius beyond that corresponding to 2.5 arc sec/year would result in a prohibitively large number of spurious matches and a significant increase in processing time while yielding extremely few (though individually interesting) additional stellar motions. The specific range of stellar magnitudes sought is from 12 to 19 red. Significant motions for stars brighter than the limit mred = 12 are already fairly well documented and the corresponding bright Schmidt images begin to show extensive contamination from diffraction spikes, “blazes” radially away from the plate center, and photographic “bloom”. At the other limit, although images of stars fainter than mred = 19 are visually discernible on the plates (the plate limit is typically mred= 20), inspection of the faintest images reveals that they are amorphous and often quite asymmetric clusters of photographic grain. Thus, both the motion limits and the magnitude limits for the survey have been selected to cover the range of reliable and largely unexplored data on the plate material. The implementation of APMS, then, is tailored to these goals and ranges.

scholarly journals Stellar Kinematics in the Galactic North Pole Region on the Basis of Tautenburg Schmidt Telescope Plates

1994 ◽  
Vol 161 ◽  
pp. 444-446
Author(s):  
N.V. Kharchenko ◽  
E. Schilbach ◽  
R.-D. Scholz
Keyword(s):  
Spatial Distribution ◽  
Galactic Plane ◽  
North Pole ◽  
Proper Motions ◽  
Stellar Kinematics ◽  
Schmidt Telescope ◽  
The North ◽  
Spatial Velocity ◽  
North Galactic

The spatial velocity components and their dispersions in the Galactocentric and rotation directions, eccentricities of Galactic orbits, parameters of spatial distribution and the change of all these characteristics with distance from the Galactic plane are detennined. These data have been obtained on the basis of absolute proper motions and stellar B, V magnitudes in two sky regions near the North Galactic Pole (NGP) by means of a plate set of the Tautenburg Schmidt telescope.

scholarly journals From Milliarcsecond Proper Motions to the Discovery of Dark Matter: Some Winning Cards still in the hands of Photographic Astronomy

1995 ◽  
Vol 148 ◽  
pp. 90-95
Author(s):  
J. Guibert ◽  
J. Souchay
Keyword(s):  
Dark Matter ◽  
Proper Motion ◽  
Large Field ◽  
Proper Motions ◽  
Ccd Cameras ◽  
The Subject ◽  
Motion Studies ◽  
Ccd Detectors

AbstractThe large field of Schmidt plates allows monitoring of hundreds of thousands or even millions of stars, either for magnitude variations or for proper motions. CCD cameras benefit from the sensitivity, linearity, and easy interface to computers of detectors of increasing dimensions. However, especially for proper motion studies, there is no substitute to plates of first or intermediate epochs. In addition, the photographic plates, with their large sky coverage free of gaps, are irreplaceable for the accurate astrometry of optical counterparts of sources detected at other wavelengths.We first introduce the subject by mentioning a few problems concerning the replacement of Schmidt plates by CCD detectors. After a brief survey of astronomical applications requiring accurate astrometry or massive processing in large fields, we develop in more detail the results obtained in proper motion studies by several groups using the MAMA system (Berger et al. 1991). The last part of this paper is devoted to the studies of stellar variability and to the EROS and DUO microlensing programmes. Our conclusion (not a surprise, we think), is that Schmidt telescopes with photographic facilities should remain available to the general astronomical community for at least a decade and probably more.

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