- ID:
- ivo://CDS.VizieR/J/MNRAS/361/1055
- Title:
- BVI photometry of LMC Be stars
- Short Name:
- J/MNRAS/361/1055
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue with coordinates and photometric data of 2446 Be star candidates in the Large Magellanic Cloud (LMC), based on a search of the OGLE II data base. The I-band light curves of these stars show outbursts in 24% of the sample (Type-1 stars), high and low states in 10%, periodic variations in 6% (Type-3 stars), and stochastic variations in 60% of the cases. We report on the result of the statistical study of light curves of Type-1 and Type-3 stars in the LMC, and the comparison with the previously reported results of the Small Magellanic Cloud (SMC) sample.
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- ID:
- ivo://CDS.VizieR/J/AJ/134/2168
- Title:
- BVI photometry of M33 star clusters
- Short Name:
- J/AJ/134/2168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a survey for star clusters in M33 using HST WFPC2 archive images. We have found 104 star clusters, including 32 new ones, in the images of 24 fields that were not included in previous studies. Combining these with previous data in the literature, we increase the number of M33 star clusters found in the HST images to 242. We have derived BVI integrated photometry of these star clusters from the CCD images taken with the CFH12k mosaic camera at the CFHT.
- ID:
- ivo://CDS.VizieR/J/PASP/126/733
- Title:
- BVI photometry of M15 stars
- Short Name:
- J/PASP/126/733
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new BVI photometry containing 40,000 stars of the Galactic globular cluster M15 (NGC 7078), covering a 25'x25' area centered on the cluster with a magnitude range from the tip of the red giant branch to 3 mag below the main sequence turnoff. Using {alpha}-enhanced Dartmouth Stellar Evolution Program models, we find an age of 13.0+/-1.0Gyr and distance modulus of (m-M)_V_=15.4+/-0.1 through isochrone fitting. Unlike previous works, we find good agreement between the observed completeness-corrected stellar luminosity function and models.
- ID:
- ivo://CDS.VizieR/J/MNRAS/335/291
- Title:
- BVI photometry of NGC 2547
- Short Name:
- J/MNRAS/335/291
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have developed the techniques required to use Naylor's optimal photometry algorithm of to create colour-magnitude diagrams with well-defined completeness functions. To achieve this we first demonstrate that the optimal extraction is insensitive to uncertainties in the measured position of the star. We then show how to correct the optimally extracted fluxes such that they correspond to those measured in a large aperture, so aperture photometry of standard stars can be used to place the measurements on a standard system. The technique simultaneously removes the effects of a position-dependent point spread function. Finally, we develop a method called 'ghosting', which calculates the completeness corrections in the absence of an accurate description of the point spread function. We apply these techniques to the young cluster NGC 2547 (=C0809-491), and use an X-ray-selected sample to find an age of 20-35Myr and an intrinsic distance modulus of 8.00-8.15mag. We use these isochrones to select members from our photometric surveys. Our derived luminosity function shows a well-defined Wielen dip, making NGC 2547 the youngest cluster in which such a feature has been observed. Our derived mass function spans the range 0.1-6M_{sun}_ and is similar to that for the field and the older, more massive clusters M35 and the Pleiades, supporting the idea of a universal initial mass function.
- ID:
- ivo://CDS.VizieR/J/MNRAS/377/1737
- Title:
- BVI photometry of NGC 2489
- Short Name:
- J/MNRAS/377/1737
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD BVI photometry for the southern open cluster NGC 2489 and its surrounding field. The sample consists of 2182 stars measured in an area of 13.6'x13.6', extending down to V~21.5. These data are supplemented with CORAVEL radial-velocity observations for seven red giant candidates. A cluster angular radius of 6.7+/-0.6', equivalent to 3.5+/-0.3pc, is estimated from star counts carried out inside and outside the cluster region. The comparison of the cluster colour-magnitude diagrams with isochrones of the Padova group yields E(B-V)=0.30+/-0.05, E(V-I)=0.40+/-0.05 and V-MV=12.20+/-0.25 for logt=8.70 (t=500^+130^_-100_Myr) and Z=0.019. NGC 2489 is then located at 1.8+/-0.3kpc from the Sun and 25pc below the Galactic plane. The analysis of the kinematical data allowed us to confirm cluster membership for six red giants, one of them being a spectroscopic binary. A mean radial velocity of 38.13+/-0.33km/s was derived for the cluster red giants. The properties of a sample of open clusters aligned along the line of sight of NGC 2489 are examined.
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/599
- Title:
- BVI photometry of NGC 5288
- Short Name:
- J/MNRAS/367/599
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present charge-coupled device (CCD) images in the Johnson B and V and Kron-Cousins I passbands for the previously unstudied open cluster NGC 5288. The sample consists of 15688 stars reaching down to V~20.5. The cluster appears to have a relatively small but conspicuous nucleus and a low-density extended coronal region.
- ID:
- ivo://CDS.VizieR/J/ApJ/652/1133
- Title:
- BVI photometry of NGC 4258 Cepheids
- Short Name:
- J/ApJ/652/1133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present initial results from a time series BVI survey of two fields in NGC 4258 using the HST ACS. This galaxy was selected because of its accurate maser-based distance, which is anticipated to have a total uncertainty of 3%. The goal of the HST observations is to provide an absolute calibration of the Cepheid distance scale and to measure its dependence on chemical abundance (the so-called metallicity effect). We carried out observations of two fields at different galactocentric distances with a mean abundance difference of 0.5dex. We discovered a total of 281 Cepheids with periods ranging from 4 to 45 days (the duration of our observing window).
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/2872
- Title:
- BVI photometry of NGC 4261 globular clusters
- Short Name:
- J/MNRAS/421/2872
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the globular cluster (GC) population of the elliptical galaxy NGC 4261 based on Hubble Space Telescope Wide Field Planetary Camera 2 data in the B, V and I bands. We study the spatial distribution of the GCs in order to probe the anisotropy in the azimuthal distribution of the discrete X-ray sources in the galaxy revealed by Chandra images.
- ID:
- ivo://CDS.VizieR/J/AcA/49/223
- Title:
- BVI photometry of OGLE LMC Cepheids
- Short Name:
- J/AcA/49/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Catalog of Cepheids from the LMC. The Catalog contains 1333 objects detected in the 4.5 square degree area of central parts of the LMC. About 3.4*10^5^ BVI measurements of these stars were collected during the OGLE-II microlensing survey. The Catalog data include period, BVI photometry, astrometry, and R_21_, phi_21_ parameters of the Fourier decomposition of I-band light curve. The vast majority of objects from the Catalog are the classical Cepheids pulsating in the fundamental or first overtone mode. The remaining objects include Population II Cepheids and red giants with pulsation-like light curves. Tests of completeness performed in overlapping parts of adjacent fields indicate that completeness of the Catalog is very high: >96%. Statistics and distributions of basic parameters of Cepheids are also presented. Finally, we show the light curves of three eclipsing systems containing Cepheid detected among objects of the Catalog. All presented data, including individual BVI observations are available from the OGLE Internet archive at URL: ftp://sirius.astrouw.edu.pl/ogle/ogle2/var_stars/lmc/cep/catalog/
- ID:
- ivo://CDS.VizieR/J/AcA/49/437
- Title:
- BVI photometry of OGLE SMC Cepheids
- Short Name:
- J/AcA/49/437
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Catalog of Cepheids from the SMC which contains data for 2049 objects detected in the 2.4 square degree area of central parts of the SMC. For each object period, BVI photometry, astrometry, and R_21_, {phi}_21_ parameters of the Fourier decomposition of I-band light curve are provided. The Catalog is based on observations collected during the OGLE-II microlensing survey. Tests of completeness performed in overlapping parts of adjacent fields indicate that completeness of the Catalog is very high: approx 92%. Statistics and distributions of basic parameters of Cepheids are also presented. All presented data, including individual BVI observations (approx 4.7*10^5^ BVI measurements), are available from the OGLE Internet archive at URL: ftp://sirius.astrouw.edu.pl/ogle/ogle2/var_stars/smc/cep/catalog
