- ID:
- ivo://CDS.VizieR/J/A+A/402/509
- Title:
- uvby photometry of four MC eclipsing binaries
- Short Name:
- J/A+A/402/509
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new accurate CCD uvby light curves for the LMC eclipsing binaries HV 982 and HV 12578, and for the SMC systems HV 1433 and HV 11284 obtained at the Danish 1.5m telescope at ESO, La Silla, equipped with a direct camera and CCD #28 (a thinned 1024x1024 Tek device), during several periods between November 1992 and November 1995. The light curves were derived from DoPHOT photometry, and typical accuracies are between 0.007 and 0.012mag per point. Standard uvby indices have also been established for each binary, primarily for determination of interstellar reddening and absorption. For HV 982 and HV 12578, accurate photometric elements have been established. Both systems consist of two detached components of comparable sizes in an eccentric orbit.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/581/A66
- Title:
- UV variability and accretion in NGC 2264
- Short Name:
- J/A+A/581/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric variability is a distinctive feature of young stellar objects; exploring variability signatures at different wavelengths provides insight into the physical processes at work in these sources. We explore the variability signatures at ultraviolet (UV) and optical wavelengths for several hundred accreting and non-accreting members of the star-forming region NGC 2264 (~3Myr).
- ID:
- ivo://CDS.VizieR/J/A+A/416/811
- Title:
- V and R CCD photometry of visual binaries
- Short Name:
- J/A+A/416/811
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 429 CCD measurements of relative positions and magnitude differences in V and R photometric bands for 165 visual double and multiple stars are given. CCD frames were taken at the 1.52m Spanish telescope of the Spanish-German Center of Astronomy at Calar Alto (Almeria, Spain). During the reduction process a "Tepui" function was used as the PSF function.
- ID:
- ivo://CDS.VizieR/J/AcA/63/339
- Title:
- Variability Survey in Stock 14 cluster
- Short Name:
- J/AcA/63/339
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a photometric variability survey in the young open cluster Stock 14 and the surrounding fields. In total, we detected 103 variable stars of which 88 are new discoveries. We confirm short-period, low-amplitude light variations in two eclipsing members of the cluster, HD 101838 and HD 101794. In addition, we find two new {beta} Cep stars of which one, HD 101993, is also a member. The sample of pulsating cluster members is supplemented by one multimode slowly pulsating B-type star and several single-mode candidates of this type. The other pulsating stars in our sample are mostly field stars. In particular, we found 14 {delta} Sct stars including one {gamma} Dor/{delta} Sct hybrid pulsator.
- ID:
- ivo://CDS.VizieR/J/MNRAS/298/753
- Title:
- Variables in Cygnus OB2
- Short Name:
- J/MNRAS/298/753
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the photometric CCD search for B-type variables in the central region of the Cygnus OB2 association. We discover 29 new variables including two Beta Cephei stars. The photometric data in the Cousins I band are given in file photom.dat. In addition, we present BV(RI)c and H_{alpha}_ photometry for stars in the observed field. This is Table 4 of the paper, available only in electronic form.
- ID:
- ivo://CDS.VizieR/J/A+AS/120/139
- Title:
- Variables in Omega Cen Fields 5139A-C
- Short Name:
- J/A+AS/120/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tables 11-50 contain V band light curves for 40 variables reported in the paper. Tables 51-53 and 54-56 contain VI photometry presented in Figs. 12 and 13, respectively.
- ID:
- ivo://CDS.VizieR/J/A+AS/122/471
- Title:
- Variables in Omega Cen Fields 5139D-F
- Short Name:
- J/A+AS/122/471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tables 1-30 contain V band light curves for 30 variables reported in the paper. Tables 31-33 and 34-36 contain VI photometry presented in Figs. 8 and 9, respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/110/2166
- Title:
- Variables in Sextans dSph galaxy
- Short Name:
- J/AJ/110/2166
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a survey for variable stars in the Sextans dwarf spheroidal (dSph) galaxy based on the analysis of 113 B and 48 V CCD images of four fields covering a total area of 18'x18'. We have identified 44 variables: 36 RR Lyr star, 6 anomalous Cepheids, one long-period red variable, all probable members of Sextans, and one foreground contact binary. We have used the pulsating stars to derive a true distance modulus of 19.67+/-0.15 for Sextans (or D=86+/-6kpc), where the error is primarily due to uncertainties in the luminosity-metallicity relation for RR Lyr stars. Based on our new data we conclude that [Fe/H]_Sex=-1.6+/-0.2, somewhat higher than the value from Suntzeff et al. (1993ApJ...418..208S) obtained from the analysis of fiber spectroscopy of the near-IR Calcium triplet. We present a new deep color-magnitude diagram for Sextans which reveals the presence of anomalous Cepheids in the galaxy. This young population may represent as much as 25% of the total stellar content of Sextans. We find a surprisingly strong correlation between the frequency of anomalous Cepheids in dSph galaxies and galaxian luminosity and speculate on the possible origin of this strange effect. The RR Lyr stars in Sextans do not exhibit the Oosterhoff dichotomy observed in globular clusters and in the Galactic halo field.
- ID:
- ivo://CDS.VizieR/J/A+A/463/589
- Title:
- Variables stars in NGC 362
- Short Name:
- J/A+A/463/589
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 362 is a bright southern globular cluster in the foreground of the Small Magellanic Cloud (SMC), for which no extensive variability survey has ever been done. Finding regularly pulsating RR Lyrae stars in the cluster can lead to improved metallicity and distance estimates of the system, while other types of variable objects may be used to confirm the results. Time-series CCD photometric observations have been obtained. Light curves have been derived with both profile fitting photometry and image subtraction. We developed a simple method to convert flux phase curves to magnitudes, which allows the use of empirical light curve shape vs. physical parameters calibrations. Periods and light curve parameters of the detected variable stars have been determined with Fourier analysis, phase dispersion minimization and string-length minimization. Using the RR Lyrae metallicity and luminosity calibrations, we have determined the relative iron abundances and absolute magnitudes of the stars. The color-magnitude diagram has been fitted with Yale-Yonsei isochrones to determine reddening and distance independently. For five RR Lyrae stars we obtained radial velocity measurements from optical spectra. We found 45 RR Lyr stars, of which the majority are new discoveries. While most of them are cluster members, as shown by their radial velocities and positions in the color-magnitude diagram, we also see a few stars in the galactic field and in the outskirts of the SMC. About half of the RR Lyraes exhibit light curve changes (Blazhko effect). The RR Lyrae-based metallicity of the cluster is [Fe/H]=-1.16+/-0.25, the mean absolute magnitude of the RR Lyrae stars is M_V=0.82+/-0.04mag implying a distance of 7.9+/-0.6kpc. The mean period of RRab stars is 0.585+/-0.081days. These properties place NGC 362 among the Oosterhoff type I globular clusters. The isochrone fit implies a slightly larger distance of 9.2+/-0.5kpc and an age of 11+/-1Gyr. We also found 11 eclipsing binaries, 14 pulsating stars of other types, including classical Cepheids in the SMC and 15 variable stars with no firm classification. NGC 362 hosts a large number of RR Lyrae stars, which makes the cluster a potentially important test object for studying the Blazhko effect in a chemically homogeneous environment.
- ID:
- ivo://CDS.VizieR/J/A+A/367/759
- Title:
- Variable stars in IC 1613
- Short Name:
- J/A+A/367/759
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby galaxies IC 1613 and NGC 6822 were observed over four years to detect short period Cepheids and to obtain good light curves for Fourier decomposition. The program was carried out with a relatively small telescope, the Dutch 0.9m at ESO-La Silla, and the observations were performed without filter (white light), or Wh-band. In this paper we present the results of the observations of Fields C and D in IC 1613 (3.8'x3.8' each). The analysis of the light curves of 3297 stars in the two fields has allowed the detection of 92 variable stars. A total of 34 Population I Cepheids have been found, while only 7 of these objects were previously known in these fields. Most of the stars have short periods and some of them are first overtone mode pulsators. Among the other variable stars there are one eclipsing binary and five W Vir candidates. A nova event was observed in Field D.
