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- ID:
- ivo://CDS.VizieR/J/A+A/462/245
- Title:
- BVI photometry in NGC 6611
- Short Name:
- J/A+A/462/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observation of young stars with circumstellar disks suggests that the disks are dissipated, starting from the inner region, by the radiation of the central star and eventually by the formation of rocky planetesimals, over a time scale of several million years. It was also shown that strong UV radiation emitted by nearby massive stars can heat a circumstellar disk up to some thousand degrees, inducing the photoevaporation of the gas. This process strongly reduces the dissipation time scale. We study whether there exists a correlation between the spatial distribution of stars with circumstellar disks and the position of massive stars with spectral class earlier than B5, in the open cluster NGC 6611. We created a multiband catalog of the cluster, down to V~23mag, using optical data from a WFI observation at 2.2m of ESO in the BVI bands, the 2MASS public point source catalog and an archival X-ray observation made with CHANDRA/ACIS. We selected the stars with infrared excess (due to the emission of a circumstellar disk) using suitable color indices independent of extinction, and studied their spatial distribution.
- ID:
- ivo://CDS.VizieR/J/PASP/114/298
- Title:
- BVI photometry in NGC 300
- Short Name:
- J/PASP/114/298
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on 13 nights of observations of four fields in NGC 300, we have set up an extensive sequence of stars with accurate BVI photometry covering a relatively large (25'x25') region centered on this galaxy. This sequence of standard stars is very useful for calibrating the photometry of variable stars and other objects in NGC 300 and other galaxies obtained from wide-field mosaic images. Our standard-star list contains B, V, and I measurements for 390 stars. The accuracy of the zero points in the V filter and B-V color is better than 0.02mag, and about 0.03mag for the V-I color. We found very good agreement between our measurements and those previously obtained by Walker for 26 stars near NGC 300.
- ID:
- ivo://CDS.VizieR/J/PASP/115/413
- Title:
- BVI photometry in the open cluster NGC 6791
- Short Name:
- J/PASP/115/413
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present broadband BVI photometry for the open cluster NGC 6791, based upon analysis of 1764 individual CCD images. Data tables listing measured magnitudes and standard errors, image-quality indices, a variability index, and equinox J2000.0 equatorial coordinates for 14,342 stars to V~24 have been made available to the public through the services of the Canadian Astronomy Data Centre. Equatorial coordinates only have been provided for a further 1916 stars, the photometry for which we were unable to calibrate because of lack of color information.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/1202
- Title:
- BVI photometry in W5E HII region
- Short Name:
- J/MNRAS/415/1202
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to present the results of photometric investigations of the central cluster of the W5 E HII region as well as a follow-up study of the triggered star formation in and around bright-rimmed clouds (BRCs). We have carried out wide-field UBVIc and deep VIc photometry of the W5 E HII region. A distance of ~2.1kpc and a mean age of ~1.3Myr have been obtained for the central cluster. The young stellar objects (YSOs) associated with the region are identified on the basis of near-infrared and mid-infrared observations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/424/1132
- Title:
- BVI photometry of Be 27, Be 24 and Be 36
- Short Name:
- J/MNRAS/424/1132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present the investigation of the evolutionary status of three open clusters: Berkeley 27, Berkeley 34 and Berkeley 36, all located in the Galactic anticentre direction. All of them were observed with SUperb Seeing Imager 2 at the New Technology Telescope using the Bessel B, V and I filters.
- ID:
- ivo://CDS.VizieR/J/AJ/121/861
- Title:
- BVI photometry of central part of M33
- Short Name:
- J/AJ/121/861
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The DIRECT project aims to determine direct distances to two important galaxies in the cosmological distance ladder - M31 and M33 - using detached eclipsing binaries (DEBs) and Cepheids. The search for these variables requires time-series photometry of large areas of the target galaxies and yields magnitudes and positions for tens of thousands of stellar objects, which may be of use to the astronomical community at large. During the first phase of the project, between 1996 September and 1997 October, we were awarded 95 nights on the F. L. Whipple Observatory 1.2 m telescope and 36 nights on the Michigan-Dartmouth-MIT 1.3 m telescope to search for DEBs and Cepheids in the M31 and M33 galaxies. This paper, the first in our series of stellar catalogs, lists the positions, three-color photometry, and variability indices of 57,581 stars with 14.4<V<23.6 in the central part of M33. The catalog is available from our FTP site.
- ID:
- ivo://CDS.VizieR/J/AJ/141/92
- Title:
- BVI photometry of 10 distant open clusters
- Short Name:
- J/AJ/141/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The oldest open star clusters are important for tracing the history of the Galactic disk, but many of the more distant clusters are heavily reddened and projected against the rich stellar background of the Galaxy. We have undertaken an investigation of several distant clusters (Berkeley 19, Berkeley 44, King 25, NGC 6802, NGC 6827, Berkeley 52, Berkeley 56, NGC 7142, NGC 7245, and King 9) to develop procedures for separating probable cluster members from the background field. We next created a simple quantitative approach for finding approximate cluster distances, reddenings, and ages. We first conclude that with the possible exception of King 25 they are probably all physical clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/544/A73
- Title:
- BVI photometry of Fornax dSph galaxy
- Short Name:
- J/A+A/544/A73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep photometry in the B,V and I filters from CTIO/MOSAIC for about 270.000 stars in the Fornax dwarf Spheroidal galaxy, out to a radius of r_ell_~0.8{deg}. By combining the accurately calibrated photometry with the spectroscopic metallicity distributions of individual Red Giant Branch stars we obtain the detailed star formation and chemical evolution history of Fornax. Fornax is dominated by intermediate age (1-10Gyr) stellar populations, but also includes ancient (10-14Gyr), and young (<1Gyr) stars. We show that Fornax displays a radial age gradient, with younger, more metal-rich populations dominating the central region. This confirms results from previous works. Within an elliptical radius of 0.8 degrees, or 1.9kpc from the centre, a total mass in stars of 4.3*10^7^M_{sun}_ was formed, from the earliest times until 250Myr ago. Using the detailed star formation history, age estimates are determined for individual stars on the upper RGB, for which spectroscopic abundances are available, giving an age-metallicity relation of the Fornax dSph from individual stars. This shows that the average metallicity of Fornax went up rapidly from [Fe/H]<-2.5dex to [Fe/H]=-1.5dex between 8-12Gyr ago, after which a more gradual enrichment resulted in a narrow, well-defined sequence which reaches [Fe/H]~-0.8dex, ~3Gyr ago. These ages also allow us to measure the build-up of chemical elements as a function of time, and thus determine detailed timescales for the evolution of individual chemical elements. A rapid decrease in [Mg/Fe] is seen for the stars with [Fe/H]>-1.5dex, with a clear trend in age.
- ID:
- ivo://CDS.VizieR/J/A+A/404/423
- Title:
- BVI photometry of Galactic Cepheids
- Short Name:
- J/A+A/404/423
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 321 Galactic fundamental-mode Cepheids with good B,V,I photometry by Berdnikov et al. (2000, Cat. <J/A+AS/143/211>) and with homogenized color excesses E(B-V) based on Fernie et al. (1995IBVS.4148....1F) are used to determine their period-colour relation in the range 0.4<log P<1.6. Distances of 25 Cepheids in open clusters (Feast, 1999PASP..111..775F) and of 28 Cepheids with BBW distances (Gieren et al., 1998ApJ...496...17G) are used in a first step to determine the absorption coefficients R_B_=4.17, R_V_=3.17, and R_I_=1.89. The two sets define two independent P-L relations which agree very well in slope. They are therefore combined into a single mean Galactic P-L relation.
