An analysis of more than 2000 CCD observations of the field RR Lyrae star NSV 09295 shows that the star is a double-mode RR Lyrae (RRd) variable with P_0_=0.46334d and P_1_=0.34423d. This brings the total of known field RRd stars in the Milky Way galaxy to four. These four variables are compared with the RRd stars in galactic globular clusters and with the field RRd stars in the LMC, and in the Draco and Sculptor dwarf galaxies. It appears that all known RRd stars have a metal abundance of less than [Fe/H]=-1.6. (c) 1997 American Astronomical Society.
NSV 11154 has been confirmed as a new member of the rare hydrogen- deficient R Coronae Borealis (RCB) stars based on new photometric and spectroscopic data. Using new photometry, as well as archival plates from the Harvard archive, we have constructed the historical lightcurve of NSV 11154 from 1896 to the present. The lightcurve shows the sudden, deep, irregularly spaced declines characteristic of RCB stars.
We have identified 4659 variable objects in the Northern Sky Variability Survey. We have classified each of these objects into one of the five variable star classes: (1) Algol/alpha Lyr systems including semidetached, and detached eclipsing binaries, (2) W Ursae Majoris overcontact and ellipsoidal variables, (3) long-period variables such as Cepheid and Mira-type objects, (4) RR Lyr pulsating variables, and (5) short-period variables including delta Scuti stars. All the candidates have outside of eclipse magnitudes of ~10-13.
Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) near-ultraviolet (NUV) echelle spectra reveal complex structure in the sight line toward the Weigelt D condensation located 0.25" north-northwest of {eta} Car. This analysis uses data recorded between 2000 October and 2004 March to monitor changes in emission and absorption as the UV photoexciting fluxes from {eta} Car drop and later reappear. We compare changes in the wind profiles seen against the star and the CS absorptions to gain knowledge of the properties of the extended wind and the ejecta. Complete spectra, in the wavelength region 2424-2706{AA}, with line identifications are available in the electronic edition of this paper.
An analysis of V photometric light curves of the eclipsing cataclysmic variable SDSS J150240.98+333423.9/NZ Boo obtained in April-June, 2012 with a CCD photometer using the 60-cm telescope of the Sternberg Astronomical Institute's Crimean station is presented (based on more than 750 images). The first observation was made ~350-370 orbital cycles after the beginning of the outburst of April 2012; all the observations correspond to quiescence of the system. The orbital period, P = 0.0589106(4)d, changed by no more than {Delta}Porb/Porb~2x10^-5^ during the more than 37200 orbital cycles since the previous observations of the system.
We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. The six maps from 1999-2002 are based on previously unpublished observations. Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent active longitudes.
The period changes of 86 M5 RR Lyrae stars have been investigated on a 100-yr time base. The published observations have been supplemented by archival Asiago, Konkoly and Las Campanas photographic observations obtained between 1952 and 1993.
This 64th compilation contains the results of visual and photographic observations of BAV-members from the years 2088 and 2009. Here we publish altogether 193 minima and maxima of 130 eclipsing binaries and pulsating stars. The data were acquiered by 13 observers.
Observations of RR Lyrae variables near the transition between fundamental and first-overtone mode in the Oosterhoff type II (Oo II) globular clusters M80, M9, and NGC 2298 have been analyzed in a search for double-mode pulsators (RRd stars). These three clusters were selected because they have metal abundances that are intermediate between those of the Oo II clusters and the Oo I clusters that are known to have RRd stars. Any RRd stars identified in these three clusters would be useful for verification of a mass-metallicity relation. The analysis was based on published observations for all three clusters, and in addition, 44 CCD frames of M9 and 32 photographs of NGC 2298, all obtained with the University of Toronto telescope at Las Campanas. No new RRd stars were discovered. It is noted that the only globular clusters known to have RRd stars are the most metal poor Oo I clusters and metal poor Oo II clusters. Published observations of the RRd stars in M15 have been analyzed in order to determine accurate periods and period ratios for stars whose periods were previously considered to be uncertain.
A catalogue of all the periods published up to 31 October 1996 on 364 CP stars is presented; it supersedes the previous version (catalog <III/152>). The paper version (catalog.tex) is arranged in three tables: the bulk of the data, i.e. those referring to CP2, CP3, and CP4 stars, are given in Table 1, while the data concerning He-strong stars are given in Table 2 and those for eclipsing or ellipsoidal variables are collected in Table 3. Notes are also provided at the end of each table, mainly about duplicities. The machine-readable version was arranged in two main parts: the main parameters of the 364 stars (identifiers and names, positions, spectral types, magnitudes and peculiarities) are tabulated in the file 'stars'; periods and the of the observed variations (light, spectrum, magnetic field, etc.) are listed in the 'periods' file. Two other files contains the notes and the references.
