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- ID:
- ivo://CDS.VizieR/J/other/JAD/17.2
- Title:
- CY Aqr differential light curves
- Short Name:
- J/other/JAD/17.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 24 new times of maximum of the SX Phoenicis star CY Aquarii. These times lead to a slightly more precise local linear ephemeris for 2003-2010.
- ID:
- ivo://CDS.VizieR/J/other/JAD/18.2
- Title:
- CY Aqr multiband photometry: 2011 season
- Short Name:
- J/other/JAD/18.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on more than a dozen partial nights of filterless CCD photometry combined with Stromgren uvby photomultiplier photometry, we derive 29 new times of maximum light of the SX Phoenicis star CY Aquarii. These times support a linear ephemeris for 2003-2011. In addition, we present uvby light curves for this star. Our dataset displays the smallest residual spread compared to any other substantial dataset published during the last decade.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A103
- Title:
- 43 Cyg decorrelated 156-day light curve
- Short Name:
- J/A+A/608/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric time series of the gamma Doradus star 43 Cyg obtained with the BRITE-Constellation nano-satellites allow us to study its pulsational properties in detail and to constrain its interior structure. We aim to find a g-mode period spacing pattern that allows us to determine the near-core rotation rate of 43 Cyg and redetermine the star's fundamental atmospheric parameters and chemical composition. We conducted a frequency analysis using the 156-days long data set obtained with the BRITE-Toronto satellite and employed a suite of MESA/GYRE models to derive the mode identification, asymptotic period spacing and near-core rotation rate. We also used high-resolution, high signal-to-noise ratio spectroscopic data obtained at the 1.2m Mercator telescope with the HERMES spectrograph to redetermine the fundamental atmospheric parameters and chemical composition of 43 Cyg using the software Spectroscopy Made Easy (SME). We detected 43 intrinsic pulsation frequencies and identified 18 of them to be part of a period spacing pattern consisting of prograde dipole modes with an asymptotic period spacing of 2970(+700,-570)s. The near-core rotation rate was determined to be 0.56(+0.12,-0.14)c/d. The atmosphere of 43 Cyg shows solar chemical composition at an effective temperature of 7150+/-150K, a logg of 4.2+/-0.6dex and a projected rotational velocity, vsini, of 44+/-4km/s. The morphology of the observed period spacing patterns shows indications of the presence of a significant chemical gradient in the stellar interior.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A70
- Title:
- 28 Cygni BRITE and SMEI satellite photometry
- Short Name:
- J/A+A/610/A70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The BRITE Constellation of nanosatellites obtained mmag photometry of 28 Cygni for 11 months in 2014-2016. Observations with the Solar Mass Ejection Imager in 2003-2010 and 118 H{alpha} line profiles were added. For decades, 28 Cyg has exhibited four large-amplitude frequencies: two closely spaced frequencies of spectroscopically confirmed g modes near 1.5c/d, one slightly lower exophotospheric (Stefl) frequency, and at 0.05c/d the difference frequency between the two g modes. This top-level framework is indistinguishable from eta Cen (Paper I), which is also very similar in spectral type, rotation rate, and viewing angle. The Stefl frequency is the only one that does not seem to be affected by the difference frequency. The amplitude of the latter undergoes large variations; around maximum the amount of near-circumstellar matter is increased, and the amplitude of the Stefl frequency grows by some factor. During such brightenings dozens of transient spikes appear in the frequency spectrum, concentrated in three groups. Only eleven frequencies were common to all years of BRITE observations. Be stars seem to be controlled by several coupled clocks, most of which are not very regular on timescales of weeks to months but function for decades. The combination of g modes to the low difference frequency and/or the atmospheric response to it appears significantly nonlinear. Like in eta Cen, the difference-frequency variability seems the main responsible for the modulation of the star-to-disc mass transfer in 28 Cyg. A hierarchical set of difference frequencies may reach the longest timescales known of the Be phenomenon.
- ID:
- ivo://CDS.VizieR/J/A+A/640/A128
- Title:
- Cygnus OB2 association NIR light curves
- Short Name:
- J/A+A/640/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a J, H, and K photometric variability survey of the central 0.78 square degrees of the young OB association Cygnus OB2. We used data observed with the Wide-Field CAMera at the United Kingdom Infrared Telescope in 2007 (spanning 217 days) to investigate the light curves of 5083 low mass candidate members in the association and explore the occurrence and main characteristics of their near-infrared variability. We identified 2529 stars (~50% of the sample) with significant variability with time-scales ranging from days to months. We classified the variable stars into the following three groups according to their light curve morphology: periodic variability (1697 stars), occultation variability (124 stars), and other types of variability (726 stars). We verified that the disk-bearing stars in our sample are significantly more variable in the near-infrared than diskless stars, with a steep increase in the disk-fraction among stars with higher variability amplitude. We investigated the trajectories described by variable stars in the color-space and measured slopes for 335 stars describing linear trajectories. Based on the trajectories in the color-space, we inferred that the sample analyzed is composed of a mix of young stars presenting variability due to hot and cold spots, extinction by circumstellar material, and changes in the disk emission in the near-infrared. We contemplated using the use of near- infrared variability to identify disk-bearing stars and verified that 53.4% of the known disk-bearing stars in our sample could have been identified as such based solely on their variability. We present 18 newly identified disk- bearing stars and 14 eclipsing binary candidates among CygOB2 lower-mass members.
1497. Cyg X-1 JK light curves
- ID:
- ivo://CDS.VizieR/J/other/PZ/28.7
- Title:
- Cyg X-1 JK light curves
- Short Name:
- J/other/PZ/28.7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our long-term (13 years) J and K photometry of the X-ray binary Cyg X-1. The object's JK variability amplitudes were less than 0.2mag. The J and K orbital light curves are appreciably asymmetric in quadratures. The secondary minimum is deeper, in comparison to the primary, and it is probable that the star becomes hotter at secondary minima.
- ID:
- ivo://CDS.VizieR/J/A+A/652/A49
- Title:
- CzeV404 Her light curves and spectra
- Short Name:
- J/A+A/652/A49
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present a new study of the eclipsing cataclysmic variable CzeV404 Her (Porb=0.098d) located in the period gap. This report aims to determine the object's origin, system parameters and probe the system's accretion flow structure. We conducted simultaneous time-resolved photometric and spectroscopic observations of CzeV404 Her. We applied our light curve modeling techniques and the Doppler tomography method to determine the system parameters and analyse the structure of the accretion disk. We found that the system has a massive white dwarf M_WD_=1.00(2)M_{sun}_, a mass ratio of q=0.16, and a relatively hot secondary with an effective temperature T_2_=4100(50)K. The system inclination is 78{deg}. The accretion disk spreads out to the tidal limitation radius and has an extended hot spot/line region. The hot spot/line is hotter than the rest of the disk's outer part in quiescence or intermediate state but does not stand out completely from the disk flux in (super)outbursts. We claim that this object represents a link between two distinct classes of SU UMa-type and SW Sex-type cataclysmic variables. The accretion flow structure in the disk corresponds to the SW Sex systems, but the physical conditions inside the disk passed into behaviors of SU UMa-type objects.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/1585
- Title:
- CZ Lac multiperiodic Blazhko modulation
- Short Name:
- J/MNRAS/411/1585
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A thorough analysis of the multicolour CCD observations of the RRab-type variable, CZ Lacertae, is presented. The observations were carried out in two consecutive observing seasons in 2004 and 2005 within the framework of the Konkoly Blazhko Survey of bright, northern, short-period RRab variables.
1500. Dahlmark variables
- ID:
- ivo://CDS.VizieR/II/238
- Title:
- Dahlmark variables
- Short Name:
- II/238
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 1967 32 fields in the Milky Way were observed for variable stars. * New variable stars in Cygnus (1982IBVS.2157....1D) [8/65] Survey of an area of 20{deg}x15{deg} centered at 20h50m, +45{deg} in Cygnus. This area has been followed photographically in two colours during the period 1967 to 1981. As a rule one observation per summer was obtained. * New variable stars in Cassiopeia (1986IBVS.2878....1D) [66/105] Survey in an area 20{deg}x15{deg} centered at 1h06m, +60{deg}01'. Seventeen plate pairs exposed in the period 1967 to 1981 were collected and treated in the same way as described in the previous report. These observations provide approximate B and V magnitudes. In addition, six exposures were obtained in the period August 8 to September 23, 1985 on Technical Pan film. * New variable stars in Cygnus, Lyra and Vulpecula (1993IBVS.3855....1D) [106/185] Area of 20{deg}x15{deg} centred at 19h46m +30{deg}. * New variable stars in Cygnus, Lacerta and Andromeda (1996IBVS.4329....1D) [186/220] Area of 20{deg}x15{deg} centered at 20h40m, +45{deg} (1950). * New variable stars in the northern Milky Way (1997IBVS.4458....1D) [221/280] Area of 20{deg}x15{deg} centered at 22h42m, +60{deg} (1950) * New variable stars in the northern Milky Way (1998IBVS.4642....1D) [281/315] Results of a variable-star search in the 20{deg}x15{deg} area centered at 20h18m, +60{deg} (1950). * New variable stars in Andromeda and Cassiopeia (1999IBVS.4734....1D [316/341] Results of a variable-star search in the 20{deg}x15{deg} area centered at 0h30m, +45{deg} (1950). * New variable stars in Lyra and Cygnus (2000IBVS.4898....1D) [342/366] Results of a variable-star search in the 20{deg}x15{deg} area centered at 19h00m/+45{deg} (1950). * New variable stars along the northern Milky way (2001IBVS.5181....1D) [367/420] Results of a variable-star search in the 20{deg}x15{deg} area centered at 21h22m/+{deg} (1950).
