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Classification of Population II Stars in the Vilnius Photometric System. II. Results
Bartkevicius, A.; Lazauskaite, R.
The results of photometric classification of 848 true and suspected Population II stars, some of which were found to belong to Population I, are presented. The stars were classified using a new calibration described in Paper I (Bartkevicius & Lazauskaite 1996). We combine these results with our results from Paper I and discuss in greater detai…
The Trigonometric Parallax of the Hyades Cluster
van Altena, W. F.; Lee, J. T.; Hoffleit, E. D.
The recent completion of the Fourth Edition of the General Catalogue of Trigonometric Parallaxes (YPC) has enabled us to redetermine the trigonometric parallax of the Hyades Cluster based on individual measurements of the cluster member stars. Since the YPC has been carefully evaluated and corrected for systematic errors in both the absolute paral…
The Pulkovo catalog of 284 positions of Pluto in 1930 - 1994 based on observations from three observatories.
Ryl'Kov, V. P.; Dement'eva, A. A.; Narizhnaja, N. V.
A unique data archive of measurements and reduced positions of Pluto for the period from 1930 to 1994 has been collected from a new reduction of all photographic observations of Pluto obtained by Pulkovo astronomers. All 250 plates taken with the Pulkovo Normal astrograph were remeasured in 1993-1994. These measurements form data files that can be…
Investigation of the Guide Star Catalog
Smirnov, O. M.; Malkov, O. Y.
The Guide Star Catalog (GSC) was initially created at STScI to support the operational requirements of the Hubble Space Telescope (HST), specifically, to provide an all-sky set of reference coordinates for pointing and tracking. A new version of the catalog, GSC 1.1, includes bright stars from the HIPPARCOS INCA database. The GSC is widely used by…
The General Catalog of Positions and Proper Motions of 6637 Bright Stars (newbs)
Khrutskaya, E. V.
New positions and proper motions for stars to a limiting magnitude of 7.9 from +90 up to -90 degrees in declination over the whole sky (NewBS) were obtained as a result of a thorough revision of observational material of the International Bright Star Program. 21 catalogs with right ascensions (alpha ) and 16 catalogs with declinations (delta ) wer…
FGS Observations of Two High-Velocity Stars
Osborn, Wayne; MacConnell, D. J.
The Hubble Space Telescope Fine Guidance System has been used to obtain precise astrometry in the fields of two stars of large space velocity: R 50 = G 166-37 and W 624 = G 16-25. The measures indicate a relative trigonometric parallax for R 50 of 4.0 mas, which implies a space velocity in the galactocentric rest frame of 467 km/sec. The derived p…
The Outer Atmospheres of Cool, Low Gravity Stars as Revealed by HST
Carpenter, Kenneth G.
We have used the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST) to measure the macroturbulent and flow velocities, the acceleration of winds, and the amount of hot (transition-region) plasma in the outer atmospheres of Carbon and K - M Giant/Supergiant stars. We see the acceleration of the stellar winds in the chro…
Towards a Multi-Dimensional Stellar Classification System
Stock, J.; Agostinho, R.; Rose, J. A. +2 more
Practically all the MK spectral types known today are the result of visual inspection of photographic spectra. This includes the monumental work by Nancy Houk. Two questions related to the MK system remained unanswered all along, namely 1) How accurate are the luminosities and intrinsic colors derived from these types? And 2) Can the classificatio…