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141. B-V colour excess of Miras
ID:
ivo://CDS.VizieR/J/A+A/344/263
Title:
B-V colour excess of Miras
Short Name:
J/A+A/344/263
Date:
21 Oct 2021
Publisher:
CDS
Description:
A study of 73 carbon-rich Miras (see Subsec. 6.1) with suitable solution for 56 stars at one or several phase of their variations. In the second part, preliminary and incomplete results are reported for 17 additional Miras observed at only one phase. Table 5 contains our HC-CV-classification (see text) for the stars and their colour excess E(B-V) as determined by the method described in Subsec. 2.2.
142. BV differential photometry of 11 gamma Dor stars
ID:
ivo://CDS.VizieR/J/AJ/133/1421
Title:
BV differential photometry of 11 gamma Dor stars
Short Name:
J/AJ/133/1421
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used precise photometric and high-dispersion spectroscopic observations to study 11 gamma Doradus stars, 10 of them newly confirmed. Only five of these 11 gamma Doradus stars appear to be single; two are primaries of double-lined spectroscopic binaries, one is the secondary of a double-lined binary, two are primaries of visual binaries and, in the case of the double-lined binary (HD 86371), either or both components could be a pulsating gamma Doradus star. We have determined a preliminary orbital period of 5.32 days for the double-lined binary HD 41547. Several of the stars show spectroscopic line-profile and low-amplitude radial velocity variability indicative of pulsation. All 11 stars are photometrically variable with amplitudes between 4 and 94 mmag in Johnson B and periods between 0.38 and 1.86 days. The 11 stars have between two and five independent periods.
143. BV differential photometry of V711 Tau
ID:
ivo://CDS.VizieR/J/A+A/521/A36
Title:
BV differential photometry of V711 Tau
Short Name:
J/A+A/521/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
We attempt to establish the real nature of the orbital period variation and its relation to the spot activity of V711 Tau, and determine why the (B-V) colour of the star appears to be nearly independent of its V magnitude. We wish to verify whether existing predictions in the literature for the long-term spot activity of the star are true or not by making extended photometric observations, and whether the broad component of H{alpha} emission originates in more localised active regions, as suggested by some chromospheric models, by searching for any correlation between the base-line width of the emission and the light modulation.
144. BVI and RV curves of 5 eclipsing binaries
ID:
ivo://CDS.VizieR/J/A+A/465/943
Title:
BVI and RV curves of 5 eclipsing binaries
Short Name:
J/A+A/465/943
Date:
21 Oct 2021
Publisher:
CDS
Description:
We detected tertiary components of close binaries from spectroscopy and light curve modelling, investigated the light-travel time effect and the possibility of magnetic activity cycles, measured mass ratios for unstudied systems, and derived absolute parameters. We carried out new photometric and spectroscopic observations of five bright close eclipsing binaries, predominantly in the southern skies. We obtained full Johnson BV light curves, which were modelled with the Wilson-Devinney code. Radial velocities were measured with the cross-correlation method using IAU radial velocity standards as spectral templates. Period changes were studied with the O-C method, utilising published epochs of minimum light (XY Leo) and ASAS photometry (VZ Lib). For three objects (DX Tuc, QY Hya, V870 Ara), absolute parameters have been determined for the first time. We spectroscopically detected the tertiary components in XY Leo and VZ Lib and discovered one in QY Hya. For XY Leo we updated the light-time effect parameters and detected a secondary periodicity of about 5100d in the O-C diagram that may hint at the existence of short-period magnetic cycles. A combination of recent photometric data shows that the orbital period of the tertiary star in VZ Lib is likely to be over 1500d. QY Hya is a semi-detached X-ray active binary in a triple system with K and M-type components, while V870 Ara is a contact binary with the third smallest spectroscopic mass ratio for a W UMa star to date. Being close to the theoretical minimum for contact binaries, this small mass ratio suggests that V870 Ara has the potential of constraining evolutionary scenarios of binary mergers. The inferred distances to these systems are compatible with the Hipparcos parallaxes.
145. BVIc differential photometry of GSC 0762-110
ID:
ivo://CDS.VizieR/J/A+A/478/865
Title:
BVIc differential photometry of GSC 0762-110
Short Name:
J/A+A/478/865
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photometry of the triple-mode radially pulsating variable GSC 0762-0110 has been performed. The star has a fundamental period of 0.1945d and period ratios of 0.7641 and 0.8012. In addition two non-radial modes were found, for which the amplitude diminished considerably over the last few years. The data presented here are the B, V and Ic differential instrumental magnitudes of GSC 0762-0110 with respect to GSC 0766-2426. The V data are from four different observatories, the B and Ic data from a single observatory. Instrumental details are given in the paper.
146. BVI_c_ light curves of 57 Cepheids
ID:
ivo://CDS.VizieR/J/PAZh/40/147
Title:
BVI_c_ light curves of 57 Cepheids
Short Name:
J/PAZh/40/147
Date:
21 Oct 2021
Publisher:
CDS
Description:
In 2008-2013, we obtained 11333 CCD BV Ic frames for 57 Cepheids from the General Catalogue of Variable Stars. We performed our observations with the 76-cm telescope of the South AfricanAstronomicalObservatory (SAAO, South Africa) and the 40-cm telescope of the Cerro Armazones Astronomical Observatory of the Universidad Catolica del Norte (OCA, Chile) using the SBIG ST-10XME CCD camera. The tables of observations, the plots of light curves, and the current light elements are presented. Comparison of our light curves with those constructed from photoelectric observations shows that the differences between their mean magnitudes exceed 0.05mag in 20% of the cases. This suggests the necessity of performing CCD observations for all Cepheids.
147. BVIc light curves of 8 RR Lyr-type stars
ID:
ivo://CDS.VizieR/J/other/Obs/131.386
Title:
BVIc light curves of 8 RR Lyr-type stars
Short Name:
J/other/Obs/131.
Date:
21 Oct 2021
Publisher:
CDS
Description:
We took a total of 1175 B, V, and Ic-band CCD frames for 11 GCVS RR Lyr-type variables, for which only the coordinates were known. Observations were made with the 76-crn telescope of the South African Astronomical Observatory. We confirm the variability types, determine the periods, and build the light curves for five objects: BL Aps (P=0.598d), GR Pav (P=0.583d), HI Pav (P=0.643d), HZ Pav (P=0.803d), and IR Pav (P=0.561d). The objects SY Aps (P=0.279d) and IV Pav (P=0.408d) proved to be W UMa-type eclipsing variables; TW Aps (P=0.149d), an SX Phe-type variable; TT Aps (P=482d), an SRD-type semiregular variable, and SW Aps and GI Pav, constant stars.
148. BVIc light curves of 3 type II Cepheids
ID:
ivo://CDS.VizieR/J/AJ/139/2300
Title:
BVIc light curves of 3 type II Cepheids
Short Name:
J/AJ/139/2300
Date:
21 Oct 2021
Publisher:
CDS
Description:
Light curves in the B, V, and Ic passbands have been obtained for the type II Cepheids V154 in M3 and V42 and V84 in M5. Alternating cycle behavior, similar to that seen among RV Tauri variables, is confirmed for V84. Old and new observations, spanning more than a century, show that V154 has increased in period while V42 has decreased in period. V84, on the other hand, has shown large, erratic changes in period that do not appear to reflect the long-term evolution of V84 through the Hertzsprung-Russel diagram.
149. BVI(c) light curves of variables in M3
ID:
ivo://CDS.VizieR/J/MNRAS/372/1657
Title:
BVI(c) light curves of variables in M3
Short Name:
J/MNRAS/372/1657
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present time-series data on the variable stars of the galactic globular cluster Messier 3 (M3). We give BVI_C_ light curves for 226 RR Lyrae, 2 SX Phe and 1 W Vir type variables, along with estimated fundamental photometric parameters such as intensity and magnitude-averaged brightness and pulsation periods. In some cases, the periods we have found significantly differ from the previously published ones. This is the first published light curve and period determination for variable V266. The I-band light curve has not been observed previously for numerous (76) variables. Three new RR Lyrae variables have been discovered. Groups of RR Lyrae variables that belong to different evolutionary stages and have been separated previously on the basis of V data were found here for all colours and colour indices by cluster analysis. The I-band period-luminosity relation is also discussed. From the 66 modulated (Blazhko type) RR Lyrae stars we investigated, six are newly identified and two of them are first overtone pulsators. In the case of 13 RR Lyrae, the period of Blazhko cycle has been estimated for the first time. V252 is identified as a new RRd variable. Amplitude ratios of RRd stars have been investigated to search possible mode content changes. In contrast to previous publications no changes have been found. Problems with the sampling of the time-series of typical cluster variability surveys are demonstrated.
150. BVIc photoelectric obs. of southern Cepheids
ID:
ivo://CDS.VizieR/J/ApJS/137/209
Title:
BVIc photoelectric obs. of southern Cepheids
Short Name:
J/ApJS/137/209
Date:
21 Oct 2021
Publisher:
CDS
Description:
A total of 2097 photometric observations in the BVI_C_ system are presented for 117 Cepheids located in the southern hemisphere. The main purpose of the photometry is to provide new epochs of maximum brightness for studying Cepheid period changes, as well as to establish current light elements for the Cepheids.