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17211. VrI light curves of NGC7099 variables
ID:
ivo://CDS.VizieR/J/A+A/555/A36
Title:
VrI light curves of NGC7099 variables
Short Name:
J/A+A/555/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the analysis of 26 nights of V and I time-series observations from 2011 and 2012 of the globular cluster M 30 (NGC 7099). We used our data to search for variable stars in this cluster and refine the periods of known variables; we then used our variable star light curves to derive values for the cluster's parameters. We used difference image analysis to reduce our data to obtain high-precision light curves of variable stars. We then estimated the cluster parameters by performing a Fourier decomposition of the light curves of RR Lyrae stars for which a good period estimate was possible. We also derive an estimate for the age of the cluster by fitting theoretical isochrones to our colour-magnitude diagram (CMD). Out of 13 stars previously catalogued as variables, we find that only 4 are bona fide variables. We detect two new RR Lyrae variables, and confirm two additional RR Lyrae candidates from the literature. We also detect four other new variables, including an eclipsing blue straggler system, and an SX Phoenicis star. This amounts to a total number of confirmed variable stars in M 30 of 12. We perform Fourier decomposition of the light curves of the RR Lyrae stars to derive cluster parameters using empirical relations. We find a cluster metallicity [Fe/H]_ZW_=-2.01+/-0.04, or [Fe/H]_UVES_=-2.11+/-0.06, and a distance of 8.32+/-0.20kpc (using RR0 variables), 8.10 kpc (using one RR1 variable), and 8.35+/-0.42kpc (using our SX Phoenicis star detection in M 30). Fitting isochrones to the CMD, we estimate an age of 13.0+/-1.0Gyr for M 30.
17212. VRI photometry and theta values in open clusters
ID:
ivo://CDS.VizieR/J/ApJS/176/262
Title:
VRI photometry and theta values in open clusters
Short Name:
J/ApJS/176/262
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, new Cousins VRI data are presented for NGC 752 and Praesepe, and new and extant data are combined into an augmented database for M67. For those three clusters, catalogs containing Cousins VRI photometry, reddening-corrected values of (V-K)J, and temperatures are produced. The same is done for Coma by using both previously published and newly derived Cousins photometry. An extant set of catalogs for the Hyades is updated to include V magnitudes and values of (R-I)C that were published after the original catalogs appeared. Finally, M67 V magnitudes published previously by Sandquist are corrected for an effect that depends on location on the face of the cluster. The corrected data and values of (V-I)C given by Sandquist are then set out in a supplementary catalog.
17213. VRI photometry in NGC 7129
ID:
ivo://CDS.VizieR/J/AJ/149/200
Title:
VRI photometry in NGC 7129
Short Name:
J/AJ/149/200
Date:
21 Oct 2021
Publisher:
CDS
Description:
NGC7129 is a bright reflection nebula located in the molecular cloud complex near l=105.4{deg}, b=+9.9{deg}, about 1.15kpc distant. Embedded within the reflection nebula is a young cluster dominated by a compact grouping of four early-type stars: BD+65{deg}1638 (B3V), BD+65{deg}1637 (B3e), SVS 13 (B5e), and LkH{alpha} 234 (B8e). About 80 H{alpha} emission sources brighter than V~23 are identified in the region, many of which are presumably T Tauri star members of the cluster. We also present deep (V~23), optical (VR_C_I_C_) photometry of a field centered on the reflection nebula and spectral types for more than 130 sources determined from low dispersion, optical spectroscopy. The narrow pre-main sequence evident in the color-magnitude diagram suggests that star formation was rapid and coeval. A median age of about 1.8Myr is inferred for the H{alpha} and literature-identified X-ray emission sources having established spectral types, using pre-main sequence evolutionary models. Our interpretation of the structure of the molecular cloud and the distribution of young stellar objects is that BD+65{deg}1638 is primarily responsible for evacuating the blister-like cavity within the molecular cloud. LkH{alpha} 234 and several embedded sources evident in near-infrared adaptive optics imaging have formed recently within the ridge of compressed molecular gas. The compact cluster of low-mass stars formed concurrently with the early-type members, concentrated within a central radius of ~0.7pc. Star formation is simultaneously occurring in a semi-circular arc some ~3pc in radius that outlines remaining dense regions of molecular gas. High dispersion, optical spectra are presented for BD+65{deg}1638, BD+65{deg}1637, SVS 13, LkH{alpha} 234, and V350 Cep. These spectra are discussed in the context of the circumstellar environments inferred for these stars.
17214. VRI photometry of Abell 3921 galaxies
ID:
ivo://CDS.VizieR/J/A+A/430/19
Title:
VRI photometry of Abell 3921 galaxies
Short Name:
J/A+A/430/19
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the analysis and results of a new VRI photometric and spectroscopic survey of the central ~1.8x1.2Mpc^2^ region of the galaxy cluster A3921 (z=0.094). We detect the presence of two dominant clumps of galaxies with a mass ratio of ~5: a main cluster centred on the Brightest Cluster Galaxy (BCG) (A3921-A), and an NW sub-cluster (A3921-B) hosting the second brightest cluster galaxy. The distorted morphology of the two sub-clusters suggests that they are interacting, while the velocity distribution of 104 confirmed cluster members does not reveal strong signatures of merging.
17215. VRI photometry of Fornax red giants
ID:
ivo://CDS.VizieR/J/AJ/127/840
Title:
VRI photometry of Fornax red giants
Short Name:
J/AJ/127/840
Date:
21 Oct 2021
Publisher:
CDS
Description:
Near-infrared spectra were obtained for 117 red giants in the Fornax dwarf spheroidal galaxy with the FORS1 spectrograph on the VLT, in order to study the metallicity distribution of the stars and to lift the age-metallicity degeneracy of the red giant branch (RGB) in the color-magnitude diagram (CMD). Metallicities are derived from the equivalent widths of the infrared calcium triplet lines at 8498, 8542, and 8662{AA} calibrated with data from globular clusters, the open cluster M67, and the LMC. For a substantial portion of the sample, the strength of the calcium triplet is unexpectedly high, clearly indicating that the main stellar population of Fornax is significantly more metal-rich than could be inferred from the position of its RGB in the CMD.
17216. VRI Photometry of Galaxies in AC118 Field
ID:
ivo://CDS.VizieR/J/A+A/389/787
Title:
VRI Photometry of Galaxies in AC118 Field
Short Name:
J/A+A/389/787
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new photometric V-, R- and I-band data for the rich galaxy cluster AC118 at z=0.31. The new photometry covers an area of 8.6x8.6arcmin^2^, corresponding to 2.9x2.9Mpc^2^ (H_0_=50km/s/Mpc, q_0_=0.5 and Lambda=0). The data have been collected for a project aimed at studying galaxy evolution through the color-magnitude relation and the fundamental plane. We provide a catalogue including all the sources (N=1206) detected in the cluster field. The galaxy sample is complete to V=22.8mag (N_gal=574), R=22.3mag (N_gal=649) and I=20.8mag (N_gal=419). We give aperture magnitudes within a fixed aperture of 4.4arcsec and Kron magnitudes. We also give photometric redshifts for 459 sources for which additional U- and K-band photometry is available. We derive and discuss the V- and R-band luminosity functions. The catalogue is intended as a tool for studies in galaxy evolution.
17217. VRI photometry of IC5070 variable stars
ID:
ivo://CDS.VizieR/J/A+A/627/A135
Title:
VRI photometry of IC5070 variable stars
Short Name:
J/A+A/627/A135
Date:
21 Oct 2021
Publisher:
CDS
Description:
We observed a field of 16'x16' in the star-forming region Pelican Nebula (IC 5070) at BVRI wavelengths for 90 nights spread over one year in 2012-2013. More than 250 epochs in VRI-bands are used to identify and classify variables up to V~21mag. We present a catalogue of optical time-series photometry with periods, mean-magnitudes and classifications for 95 variable stars including 67 pre-main-sequence variables towards star-forming region IC 5070. The pre-main-sequence variables are further classified as candidate classical T Tauri and weak-line T Tauri stars based on their light curve variations and the locations on the color-color and color-magnitude diagrams using optical and infrared data together with Gaia DR2 astrometry. Classical T Tauri stars display variability amplitudes up to three times the maximum fluctuation in disk-free weak-line T Tauri stars, which show strong periodic variations. Short-term variability is missed in our photometry within single nights. Several classical T Tauri stars display long-lasting (>10 days) single or multiple fading and brightening events up to a couple of magnitudes at optical wavelengths.
17218. VRI photometry of {lambda} Ori PMS stars
ID:
ivo://CDS.VizieR/J/AJ/118/2409
Title:
VRI photometry of {lambda} Ori PMS stars
Short Name:
J/AJ/118/2409
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have found 72 premain-sequence (PMS) stars near the center of the {lambda} Orionis star-forming region by spectroscopically testing a magnitude-limited sample for the presence of lithium {lambda}6708 absorption, a diagnostic of youth. All of these stars show large lithium equivalent widths and radial velocities consistent with Orion membership, but only two were discovered previously via H{alpha} or X-ray surveys.
17219. VRI photometry of {lambda} Ori star-forming region
ID:
ivo://CDS.VizieR/J/AJ/123/387
Title:
VRI photometry of {lambda} Ori star-forming region
Short Name:
J/AJ/123/387
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present VRI photometry of 320,917 stars with 11<~R<~18 throughout the {lambda} Ori star-forming region. Using the more spatially limited spectroscopic surveys of Dolan & Mathieu (1999, Cat. <J/AJ/118/2409>, 2001, Cat. <J/AJ/121/2124>) to define the color-magnitude domain of young low-mass members of the association and removing statistically the field stars in this domain, we use our photometry to identify a representative pre-main-sequence (PMS) population throughout the interior of the molecular ring.
17220. VRI photometry of M35
ID:
ivo://CDS.VizieR/J/ApJ/546/1006
Title:
VRI photometry of M35
Short Name:
J/ApJ/546/1006
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present very deep and accurate photometry of the open cluster M35. We have observed this association in the Cousins R, I filters, together with the Johnson V filter. We have covered a region of 27.5x27.5 square arcmin, equivalent to a fifth of the total area of the cluster. The data range from I_c_=12.5 to 23.5mag, and the color intervals are 0.4<=(V-I)_c_<=3.0, 0.5<=(R-I)_c_<=2.5. Roughly, these values span from 1.6M_{sun}_ down to the substellar limit, in the case of cluster members. By using the location of the stars on color-magnitude and color-color diagrams, we have selected candidate members of this cluster. We have merged our sample with previously published data and obtained a color-magnitude diagram for the complete stellar population of the cluster, covering the spectral range early B-mid M. Based on the distribution of field and cluster stars in color-magnitude and color-color diagrams, we estimate that two-thirds of these candidates are likely to be true members of M35. These stars approximately double the number of stars identified as candidate members of this cluster (~2700). We provide the photometry and accurate positions of these stars.

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