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2791. Photometry of beta Lyr by the BRITE satellites.II
ID:
ivo://CDS.VizieR/J/AJ/158/148
Title:
Photometry of beta Lyr by the BRITE satellites.II
Short Name:
J/AJ/158/148
Date:
21 Oct 2021
Publisher:
CDS
Description:
Observations of {beta} Lyr in four months of 2018 by three BRIght Target Explorer (BRITE) Constellation satellites, the red-filter BRITE-Toronto and BRITE-Heweliusz, and the blue-filter BRITE-Lem, permitted a first, limited look into the light-curve variability in two spectral bands. The variations were found to be well correlated outside the innermost phases of the primary eclipses with the blue variations appearing to have smaller amplitudes than the red; this reduction may reflect their presumed origin in the cooler, outer parts of the accretion disk. This result must be confirmed with more extensive material as the current conclusions are based on observations spanning slightly less than three orbital cycles of the binary. The assumption of an instrumental problem and the applied corrections made to explain the unexpectedly large amplitude of the red-filter light curve observed with the BRITE-Toronto satellite in 2016 are fully confirmed by the 2018 results.
2792. Photometry of candidate members of NGC6611
ID:
ivo://CDS.VizieR/J/A+A/496/453
Title:
Photometry of candidate members of NGC6611
Short Name:
J/A+A/496/453
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the list of candidate members of the young open cluster NGC 6611, selected in a field of view of 33'x34' by the X-rays emission and excesses in infrared bands. X-ray sources without infrared excesses are classified as candidate Class III cluster members; stars with infrared excesses as disk bearing members.
2793. Photometry of Cepheids in Magellanic Clouds
ID:
ivo://CDS.VizieR/J/ApJS/117/135
Title:
Photometry of Cepheids in Magellanic Clouds
Short Name:
J/ApJS/117/135
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report BV(RI)C data for a select group of 14 Cepheids in the Large Magellanic Cloud and eight in the Small Magellanic Cloud that have preexisting radial velocity curves. The photometry was obtained as part of a program to determine distances to these Cepheids by means of the visual surface brightness technique and to improve significantly the optical BV(RI)C light curves of Magellanic Cloud Cepheids. The data were acquired on the 0.9 m telescope at Cerro Tololo Inter-American Observatory with the CFCCD instrument and with the 1 m photometric telescope at ESO using aperture photometry. The median number of measures per Cepheid is 46 in each band, and the uncertainty in the photometry is typically 0.01 mag. Using these data together with data from the literature, we determined improved periods for all variables. For most of the Cepheids, these revised periods lead to excellent, low-noise light curves, but for a few variables, the periods are obviously variable.
2794. Photometry of chemically peculiar stars
ID:
ivo://CDS.VizieR/J/A+AS/128/245
Title:
Photometry of chemically peculiar stars
Short Name:
J/A+AS/128/245
Date:
21 Oct 2021
Publisher:
CDS
Description:
Differential Stroemgren uvby photometric observations from the Four College Automated Photoelectric Telescope are presented for four Chemically Peculiar stars of the upper main sequence: the HgMn star binary AR Aurigae and the magnetic stars 3 Hydrae, 49 Cancri, and BX Bootis. AR Aurigae shows little variability except during the primary and secondary eclipses. The 11.305 day period of Maitzen et al. for 3 Hya is confirmed. A new period of 7.0501 days is found for 49 Cancri while a slightly refined period of 2.88756 days is derived for BX Boo.
2795. Photometry of chemically peculiar stars
ID:
ivo://CDS.VizieR/J/PASP/109/9
Title:
Photometry of chemically peculiar stars
Short Name:
J/PASP/109/9
Date:
21 Oct 2021
Publisher:
CDS
Description:
Differential Stromgren uvby photometric observations from the Four College Automated Photoelectric Telescope of four magnetic Chemically Peculiar stars are used to refine rotational periods and to define the shapes of the light curves. HR 1643 (P=2.73475d) shows large phase variability in all four magnitudes. Theta Aur (P=3.6188d) exhibits large amplitude variations with two components contributing to the minima. For 49 Cam (P=4.28679d), we probably are observing both polar regions and much of the surface. The values for HR 3724 (P=33.984d) confirm Wolff's result that the main variability is in v.
2796. Photometry of CU Vir
ID:
ivo://CDS.VizieR/J/A+A/625/A34
Title:
Photometry of CU Vir
Short Name:
J/A+A/625/A34
Date:
21 Oct 2021
Publisher:
CDS
Description:
CU Vir has been the first main sequence star that showed regular radio pulses that persist for decades, resembling the radio lighthouse of pulsars and interpreted as auroral radio emission similar to that found in planets. The star belongs to a rare group of magnetic chemically peculiar stars with variable rotational period. We study the ultraviolet (UV) spectrum of CU Vir obtained using STIS spectrograph onboard the Hubble Space Telescope (HST) to search for the source of radio emission and to test the model of the rotational period evolution. We used our own far-UV and visual photometric observations supplemented with the archival data to improve the parameters of the quasisinusoidal long-term variations of the rotational period. We predict the flux variations of CU Vir from surface abundance maps and compare these variations with UV flux distribution. We searched for wind, auroral, and interstellar lines in the spectra. The UV and visual light curves display the same long-term period variations supporting their common origin. New updated abundance maps provide better agreement with the observed flux distribution. The upper limit of the wind mass-loss rate is about 10^-12^M_{sun}_/yr. We do not find any auroral lines. We find rotationally modulated variability of interstellar lines, which is most likely of instrumental origin. Our analysis supports the flux redistribution from far-UV to near-UV and visual domains originating in surface abundance spots as the main cause of the flux variability in chemically peculiar stars. Therefore, UV and optical variations are related and the structures leading to these variations are rigidly confined to the stellar surface. The radio emission of CU Vir is most likely powered by a very weak presumably purely metallic wind, which leaves no imprint in spectra.
2797. Photometry of DBS 77-78-102-160-161 regions
ID:
ivo://CDS.VizieR/J/A+A/588/A63
Title:
Photometry of DBS 77-78-102-160-161 regions
Short Name:
J/A+A/588/A63
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report a study of the global properties of some embedded clusters placed in the fourth quadrant of the MilkyWay to clarify some issues related with their location into de Galaxy and their stellar formation processes. We performed BVI photometric observations in the region of DBS 77, 78, 102, 160, and 161 clusters and infrared spectroscopy in DBS 77 region. They were complemented with JHK data from VVV survey combined with 2MASS catalogue, and used mid-infrared information from GLIMPSE catalogue. We also searched for HI data from SGPS and PMN radio surveys, and previous spectroscopic stellar classification. The spectroscopic and photometric information allowed us to estimate the spectral classification of the brightest stars of each studied region. On the other hand, we used the radio data to investigate the interstellar material parameters and the continuum sources probably associated with the respective stellar components. We estimated the basic physical parameters of the clusters (reddening, distance, age, and initial mass function). We searched for HII regions located near to the studied clusters and we analyzed the possible link between them. In the particular case of DBS 160-161 clusters, we identified the HI bubble B332.5-0.1-42 located around them. We found that the mechanical energy injected to the interstellar medium by the more massive stars of this couple of clusters was enough to generate the bubble.
2798. Photometry of 6 deep-contact W UMa
ID:
ivo://CDS.VizieR/J/other/RMxAA/53.235
Title:
Photometry of 6 deep-contact W UMa
Short Name:
J/other/RMxAA/53
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photometric observations in Sloan g' and i' bands of W UMa binaries V0637 Peg, V0473 Cam, CSS J153314.8+560527, CSS J075258.0+382035, V0416 Gem and NSVS 6859986 are presented. Their periods are in the range of 0.26-0.43d. The light curve solutions revealed that the components of each target are almost equal in temperature. The stellar components are of G and K spectral types and undergo total eclipses. All targets have deep-contact configurations with fillout factor f>=0.5. NSVS 6859986 has one o f the biggest value determined until now, f=0.84. We studied the empirical dependencies of fillout factor on the stellar parameters (temperature, period, mass ratio, relative component radii, and luminosity ratio) for a sample of around thirty stars. They are consistent with the theoretical predictions but there are deviations from the common trends.
2799. Photometry of EXors from Asiago plates
ID:
ivo://CDS.VizieR/J/A+A/602/A99
Title:
Photometry of EXors from Asiago plates
Short Name:
J/A+A/602/A99
Date:
21 Oct 2021
Publisher:
CDS
Description:
EXor objects are young variables that show episodic variations of brightness commonly associated to enhanced accretion outbursts. With the aim of investigating the long-term photometric behaviour of a few EXor sources, we present here data from the archival plates of the Asiago Observatory, showing the Orion field where the three EXors V1118, V1143, and NY are located. A total of 484 plates were investigated, providing a total of more than 1000 magnitudes for the three stars, which cover a period of about 35yrs between 1959 to 1993. We then compared our data with literature data. Apart from a newly discovered flare-up of V1118, we identify the same outbursts already known, but we provide two added values: (i) a long-term sampling of the quiescence phase; and (ii) repeated multi-colour observations (BVRI bands). The former allows us to give a reliable characterisation of the quiescence, which represents a unique reference for studies that will analyze future outbursts and the physical changes induced by these events. The latter is useful for confirming whether the intermittent increases of brightness are accretion-driven (as in the case of V1118), or extinction-driven (as in the case of V1143). Accordingly, doubts arise about the V1143 classification as a pure EXor object. Finally, although our plates do not separate NY Ori and the star very close to it, they indicate that this EXor did not undergo any major outbursts during our 40yrs of monitoring.
2800. Photometry of FG Sge at the ejection state
ID:
ivo://CDS.VizieR/J/PAZh/35/592
Title:
Photometry of FG Sge at the ejection state
Short Name:
J/PAZh/35/592
Date:
21 Oct 2021
Publisher:
CDS
Description:
New photometric observations of the variable star FG Sge, a rapidly evolving planetary nebula nucleus, were performed in 2003-2008. On 230 nights, we obtained 86 UBV and 155 BVRI (or Rc, Ic) magnitude estimates. The maximum amplitude of the V-band light variations was >8mag. Six deep minima and four high maxima were observed.