Search Publications

The Hipparcos and Tycho Photometric System Passbands

Bessell, Michael S.

Hipparcos and Tycho magnitudes have been extracted for many of the E-region standard stars. Differences between B, V, and the Hipparcos and Tycho magnitudes have been derived and regressed against color. Fiducial lines and polynomial fits have been derived and compared with values in the Hipparcos and Tycho Catalogues. Synthetic photometry has bee…

Another Search for Maia Variable Stars

Percy, John R.; Wilson, Joseph B.

We have used the Hipparcos epoch photometry database, and autocorrelation analysis, to search for the elusive Maia variables-short-period B7-A3 near-main-sequence pulsating variable stars. Of several hundred stars considered, and several dozen stars studied in detail, only a handful are possible variables: three are possible shallow eclipsing vari…

Systematic Differences between the FK5 Proper-Motion System and Hipparcos

Zhu, Zi

We present an intensive analysis of the FK5 proper-motion system via the two large astrographic catalogs, the PPM and ACRS catalogs, compared with the Hipparcos proper motions. Region-, magnitude-, and color-dependent systematic errors in the PPM and ACRS proper motions are found and exhibit similar tendencies for both catalogs. The term of the gl…

CaII K Emission-Line Asymmetry among Red Giants Detected by the ROSAT Satellite

Smith, Graeme H.; Shetrone, Matthew D.

Spectra of the Ca II H and K lines are reported for a number of field giants from which soft X-ray emission was detected by the ROSAT satellite. Several of these stars are RS CVn systems and exhibit very strong Ca II emission. The majority of the noninteracting giants in the sample have M_V>-2.0, as determined from Hipparcos parallaxe…

The δ Scuti Star DK Virginis (HR 5005) Revisited

Pamyatnykh, A. A.; Jerzykiewicz, Mikołaj

An analysis of Hp photometry of DK Virginis is carried out. The analysis reveals two frequencies, f₁=9.2095 and f₂=7.5764 cycles day^-1. These values turn out to be good enough to bridge the gap between the two available series of ground-based data, obtained in 1973 and 1980, so that the frequencies can be refined. …

V1073 Cygni: A New Light Curve and Analysis

Morris, Steven L.; Naftilan, Stephen A.

A new CCD light curve of the A-type W UMa star V1073 Cygni has been obtained, and the differential-corrections method of Wilson and Devinney was used to compute a new set of system parameters. The same analysis has been applied to the other photometric light curves in the literature, including the Hipparcos light curve. A new ephemeris is determin…

Close Approaches of Stars to the Solar System Based on Hipparcos Data

García-Sánchez, Joan