- ID:
- ivo://CDS.VizieR/J/AJ/132/1783
- Title:
- UBVRI polarimetry of 25 stars in NGC 6611
- Short Name:
- J/AJ/132/1783
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new polarimetric UBVRI observations of 25 stars in the direction of the halo of NGC 6611, the rich stellar open cluster embedded in an ionized hydrogen complex (M16). Our plan is to characterize the interstellar material (ISM) associated with halo stars in order to make a comparison with the ISM dusty core characteristics that resulted from a previous investigation by the same authors.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/462/621
- Title:
- UBVRI polarisation in NGC 5749
- Short Name:
- J/A+A/462/621
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present (UBVRI) multicolor linear polarimetric data for 31 of the brightest stars in the area of the open cluster NGC 5749 considered to study the properties of the interstellar medium (ISM) towards the cluster.
- ID:
- ivo://CDS.VizieR/J/A+A/409/933
- Title:
- UBVRI polarization in Stock 16
- Short Name:
- J/A+A/409/933
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present (UBVRI) multicolor linear polarimetric data for 26 of the brightest stars in the area of the open cluster Stock 16 that were considered to study the properties of the ISM (interstellar medium) towards the cluster. Our data yield a mean polarization percentage of P~2.5%, close to the polarization value produced by the ISM with normal efficiency (P_{lambda}_max_~5E_B-V_) undergoing a color excess of E_B-V_=0.51. The mean angle of the polarization vectors, {theta}=74.9deg, agrees quite well with the expected angle produced by dust particles aligned in the direction of the galactic disk (and the magnetic field) in the region. A study of the extinction suffered by the stars in the zone was also performed combining our new data with previous photometric data. In this sense, our analysis indicates that the visual absorption affecting Stock 16 stars is mainly produced in front of the cluster by a dust cloud at approximately 500 pc from the sun. The large polarization value of the non-member star, WR 51, confirms its background star nature.
- ID:
- ivo://CDS.VizieR/J/other/KFNT/22.231
- Title:
- UBVR photometry in NGC 6913
- Short Name:
- J/other/KFNT/22.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CCD observations of a sky area in the NGC 6913 cluster were performed with the 2-meter telescope of the Terskol Peak Observatory (Northern Caucasus, Russian Federation). The magnitudes and coordinates of stars down to V=20mag were determined for a 7'x5' field. The equatorial coordinates of stars were obtained in the reference system of the USNO A2.0 catalog (Cat. <I/252>) with an accuracy of 0.35". The relationship between the instrumental photometric system and the Johnson UBVR system was derived.
- ID:
- ivo://CDS.VizieR/J/A+A/240/262
- Title:
- UBVR photometry of the open cluster King 2
- Short Name:
- J/A+A/240/262
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present the Johnson-Cousins UBVR CCD photometry of the stars in King 2, an old open cluster towards the galactic anticenter. We have obtained the colour-magnitude diagram, the colour excess, the reddening, an estimate of the metallicity, and the distance modulus. The comparison of the observational colour-magnitude diagram with the theoretical simulations based on stellar models with convective overshoot shows that a major revision of the model structure is required. To this aim, we explore the possibility that the formulation of convective overshoot for stars in the mass range 1 to 2M_{sun}_ ought to be different from the one currently in use. The point of major uncertainty that we see to affect the stars in this domain is whether or not convective overshoot may erode the gradient in molecular weight in the regions surrounding the convective core. We find that models, in which this is not allowed to occur, better fit the overall morphology of the colour-magnitude diagram of King 2. In addition to this, analyzing the width of the main sequence band we suggest that a significant fraction of the stars are members of binary systems, and evaluate the range spanned by their mass ratios. Finally, we derive the luminosity function and the mass function for the main sequence stars of the cluster.
- ID:
- ivo://CDS.VizieR/J/A+AS/145/399
- Title:
- UKS 2 open cluster BV photometry
- Short Name:
- J/A+AS/145/399
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Colour-magnitude diagrams are presented for the first time, of the faint southern star cluster UKS 2, which was for a long time reported as a globular cluster candidate. The V vs. B-V diagrams indicate that UKS 2 is an open cluster with age comparable to that of the Hyades. It has a reddening of E(B-V)=0.40 and is located at a distance from the Sun of d_{sun}_=~7kpc. The cluster is located outside the solar radius at galactocentric distance projected on the plane r_GC_=~11kpc, and a height z=~-370pc.
- 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/447/3536
- Title:
- Variables in the fields of M35 and NGC2158
- Short Name:
- J/MNRAS/447/3536
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiyear survey aimed at collecting (1) high-precision (~5 milli-mag), (2) fast-cadence (~3-min), and (3) relatively long duration (~10d) multiband photometric series. The goal of the survey is to discover and characterize efficiently variable objects and exoplanetary transits in four fields containing five nearby open clusters spanning a broad range of ages. More in detail, our project will (1) constitute a preparatory survey for the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) mounted at the Telescopio Nazionale Galileo (TNG), which will be used for spectroscopic follow-up of any target of interest that this survey discovers or characterizes, (2) measure rotational periods and estimate the activity level of targets we are already monitoring with HARPS and HARPS-N for exoplanet transit search, and (3) long-term characterization of selected targets of interest in open clusters within the planned K2 fields. In this first paper, we give an overview of the project, and report on the variability of objects within the first of our selected fields, which contains two open clusters: M35 and NGC 2158. We detect 519 variable objects, 273 of which are new discoveries, while the periods of most of the previously known variables are considerably improved.
- ID:
- ivo://CDS.VizieR/J/MNRAS/487/3505
- Title:
- Variable stars in NGC 2244
- Short Name:
- J/MNRAS/487/3505
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of the UBVIc variability search for variable stars in the young open cluster NGC 2244. In total, we found 245 variable stars. Most of them, are pre-main sequence variables with irregular variations typical for classical T Tauri stars (CTTSs). We found also 23 periodic variables, probably weak-lined T Tauri stars (WTTSs). We detected also four candidates for {delta} Scuti stars and 7 eclipsing binaries. Based on the mid-infrared Spitzer and WISE photometry and near infrared JHKS 2MASS photometry, we classified 104 young stellar sources among our variables: 1 Class I object, 1 Class I/flat spectrum object, 4 flat spectrum objects, 91 Class II objects, and 7 transition disc objects. This classification, together with r'i'H{alpha} IPHAS photometry and JHK UKIDSS photometry, were used for identification of pre-main sequence stars among irregular and periodic variables. In this way, 97 CTTS candidates (96 irregular and one periodic variable), 68 WTTS candidates (54 irregular and 14 periodic variables), and 6 Herbig Ae/Be stars were found. For 223 variable stars we calculated membership probability based on proper motions from Gaia DR2 catalogue. Majority of them, 143 stars, are cluster members with probability greater than 70 per cent. For only 36 variable stars the membership probability is smaller than 20 per cent.
- ID:
- ivo://CDS.VizieR/J/MNRAS/386/1625
- Title:
- Velocities and photometry in NGC 2112
- Short Name:
- J/MNRAS/386/1625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a new, wide-field (20x20arcmin^2^), multicolour (UBVI), photometric campaign in the area of the nearby old open cluster NGC 2112. At the same time, we provide medium-resolution spectroscopy of 35 (and high-resolution of additional 5) red giant and turn-off stars. This material is analysed with the aim to update the fundamental parameters of this traditionally difficult cluster, which is very sparse and suffers from heavy field star contamination. Among the 40 stars with spectra, we identified 21 bona fide radial velocity members which allow us to put more solid constraints on the cluster's metal abundance, long suggested to be as low as the metallicity of globulars. As indicated earlier by us on a purely photometric basis, the cluster [Fe/H] abundance is slightly supersolar ([Fe/H]=0.16+/-0.03) and close to the Hyades value, as inferred from a detailed abundance analysis of three of the five stars with higher resolution spectra. Abundance ratios are also marginally supersolar. Based on this result, we revise the properties of NGC 2112 using stellar models from the Padova and Yale-Yonsei groups.