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- ID:
- ivo://CDS.VizieR/J/AJ/148/51
- Title:
- WIYN Open Cluster. LXI. NGC 6819 photometry
- Short Name:
- J/AJ/148/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 6819 is a richly populated, older open cluster situated within the Kepler field. A CCD survey of the cluster on the uvbyCaH{beta} system, coupled with proper-motion membership, has been used to isolate 382 highly probable, single-star unevolved main-sequence members over a 20' field centered on the cluster. From 278 F dwarfs with high precision photometry in all indices, a mean reddening of E(b-y)=0.117+/-0.005 or E(B-V)=0.160+/-0.007 is derived, where the standard errors of the mean include both internal errors and the photometric zero-point uncertainty. With the reddening fixed, the metallicity derived from the same 278 stars is [Fe/H]=-0.116+/-0.101 from m_1_ and -0.055+/-0.033 from hk, for a weighted average of [Fe/H]=-0.06+/-0.04, where the quoted standard errors of the mean include the internal errors from the photometric scatter plus the uncertainty in the photometric zero points. If metallicity is derived using individual reddening values for each star to account for potential reddening variation across the face of the cluster, the analogous result is unchanged. The cluster members at the turnoff of the color-magnitude diagram are used to test and confirm the recently discovered variation in reddening across the face of the cluster, with a probable range in the variation of {Delta}E(B-V)=0.045+/-0.015. With the slightly higher reddening and lower [Fe/H] compared to commonly adopted values, isochrone fitting leads to an age of 2.3+/-0.2Gyr for an apparent modulus of (m-M)=12.40+/-0.12.
- ID:
- ivo://CDS.VizieR/J/AJ/148/61
- Title:
- WIYN open cluster study. LIX. RVs of NGC 6791
- Short Name:
- J/AJ/148/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The open cluster NGC 6791 has been the focus of much recent study due to its intriguing combination of old age and high metallicity (~8Gyr, [Fe/H]=+0.30), as well as its location within the Kepler field. As part of the WIYN Open Cluster Study, we present precise ({sigma}=0.38km/s) radial velocities for proper motion candidate members of NGC 6791 from Platais et al. Our survey, extending down to g' ~ 16.8, is comprised of the evolved cluster population, including blue stragglers, giants, and horizontal branch stars. Of the 280 proper-motion-selected stars above our magnitude limit, 93% have at least one radial velocity measurement and 79% have three measurements over the course of at least 200 days, sufficient for secure radial-velocity-determined membership of non-velocity-variable stars. The Platais et al. proper motion catalog includes 12 anomalous horizontal branch candidates blueward of the red clump, of which we find only 4 to be cluster members. Three fall slightly blueward of the red clump and the fourth is consistent with being a blue straggler. The cleaned color-magnitude diagram shows a richly populated red giant branch and a blue straggler population. Half of the blue stragglers are in binaries. From our radial velocity measurement distribution, we find the cluster's radial velocity dispersion to be {sigma}_c_=0.62+/-0.10km/s. This corresponds to a dynamical mass of ~4600M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/AJ/146/43
- Title:
- WIYN open cluster study. LV. NGC 6819
- Short Name:
- J/AJ/146/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present proper motions and astrometric membership analysis for 15750 stars around the intermediate-age open cluster NGC 6819. The accuracy of relative proper motions for well-measured stars ranges from ~0.2mas/yr within 10' of the cluster center to 1.1mas/yr outside this radius. In the proper motion vector-point diagram, the separation between the cluster members and field stars is convincing down to V~18 and within 10' from the cluster center. The formal sum of membership probabilities indicates a total of ~2500 cluster members down to V~22. We confirm the cluster membership of several variable stars, including some eclipsing binaries. The estimated absolute proper motion of NGC 6819 is {mu}_x_^abs^=-2.6+/-0.5 and {mu}_y_^abs^=-4.2+/-0.5mas/yr. A cross-identification between the proper motion catalog and a list of X-ray sources in the field of NGC 6819 resulted in a number of new likely optical counterparts, including a candidate CV. For the first time we show that there is significant differential reddening toward NGC 6819.
- ID:
- ivo://CDS.VizieR/J/AJ/148/85
- Title:
- WIYN open cluster study. LXII. Photometry of M35
- Short Name:
- J/AJ/148/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The current generation of stellar isochrone models exhibits non-negligible discrepancies due to variations in the input physics. The success of each model is determined by how well it fits the observations, and this paper aims to disentangle contributions from the various physical inputs. New deep, wide-field optical and near-infrared photometry (UBVRIJHK_S_) of the cluster M35 is presented, against which several isochrone systems are compared: Padova, PARSEC, Dartmouth, and Y^2^. Two different atmosphere models are applied to each isochrone: ATLAS9 and BT-Settl. For any isochrone set and atmosphere model, observed data are accurately reproduced for all stars more massive than 0.7M_{sun}_. For stars less massive than 0.7M_{sun}_, Padova and PARSEC isochrones consistently produce higher temperatures than observed. Dartmouth and Y^2^ isochrones with BT-Settl atmospheres reproduce optical data accurately; however, they appear too blue in IR colors. It is speculated that molecular contributions to stellar spectra in the near-infrared may not be fully explored, and that future study may reconcile these differences.
- ID:
- ivo://CDS.VizieR/J/AJ/148/38
- Title:
- WIYN open cluster study. LX. RV survey of NGC 6819
- Short Name:
- J/AJ/148/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the current state of the WOCS radial-velocity (RV) survey for the rich open cluster NGC 6819 (2.5Gyr) including 93 spectroscopic binary orbits with periods ranging from 1.5 to 8000days. These results are the product of our ongoing RV survey of NGC 6819 using the Hydra Multi-Object Spectrograph on the WIYN 3.5m telescope. We also include a detailed analysis of multiple prior sets of optical photometry for NGC 6819. Within a 1{deg} field of view, our stellar sample includes the giant branch, the red clump, and blue straggler candidates, and extends to almost 2 mag below the main sequence (MS) turnoff. For each star observed in our survey we present all RV measurements, the average RV, and velocity variability information. Additionally, we discuss notable binaries from our sample, including eclipsing binaries (WOCS 23009, WOCS 24009, and WOCS 40007), stars noted in Kepler asteroseismology studies (WOCS 4008, WOCS 7009, and WOCS 8007), and potential descendants of past blue stragglers (WOCS 1006 and WOCS 6002). We find the incompleteness-corrected binary fraction for all MS binaries with periods less than 10^4^days to be 22%+/-3% and a tidal circularization period of 6.2^+1.1^_-1.1_days for NGC 6819.
- ID:
- ivo://CDS.VizieR/J/AJ/159/246
- Title:
- WIYN open cluster study. LXXX. Photometry of NGC 7142
- Short Name:
- J/AJ/159/246
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVRI photometry of 8702 stars in a 0.5x0.5{deg} field in the direction of NGC7142, taken with the Half Degree Imager at the WIYN 0.9m telescope, to improve knowledge of this cluster's basic parameters. Our photometry spans the ranges 10.6-20.4mag in U, 10.6-22.0mag in B, 10.0-21.8mag in V, 9.2-20.7mag in R, and 8.5-19.9mag in I. Using color-color diagrams that employ all four color combinations that include U, versus B-V, we derive a reddening-metallicity relation for the cluster, with preferred values E(B-V)=0.338{+/-}0.031mag for the left-edge fiducial of the main sequence and [Fe/H]=0.0{+/-}0.1dex, where the Hyades cluster has been used as an unreddened reference cluster, the extinction relations of Cardelli have been employed, and the metallicity dependence of the Yonsei-Yale (Y^2^) isochrones has been assumed. Comparison of our data to the Y^2^ isochrones in multiple color-magnitude diagrams (CMDs) yields distance-metallicity and age-metallicity relations, with preferred values of m-M=12.65{+/-}0.23 mag and age=4.0_+1.3_^-0.7^Gyr. Re-evaluation of the parameters of M67 using Stetson's UBVI photometry yields [Fe/H]=-0.02{+/-}0.05dex, E(B-V)=0.04{+/-}0.01mag, m-M=9.75{+/-}0.03mag, and age=3.85{+/-}0.17Gyr; we thus find the metallicity and age of the two clusters to be indistinguishable. A semi-independent analysis adopting the parameters of M67 and shifting the fiducials of the two clusters in six CMDs until they match strongly corroborates the values listed above. The differences between our inferred parallaxes and the Gaia DR2 values are 87{+/-}60{mu}as for NGC7142 and 48{+/-}15{mu}as for M67, consistent with previous studies.
- ID:
- ivo://CDS.VizieR/J/AJ/139/205
- Title:
- 2007-2008 WIYN speckle observations of binaries
- Short Name:
- J/AJ/139/205
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of 974 speckle observations of 546 binary stars are presented. Observations were obtained at the WIYN 3.5m Telescope at Kitt Peak National Observatory during the time interval from 2007 January to 2008 June. In all cases, the relative separation and position angle of the components are measured, and the magnitude difference is determined in 809 cases. The precision of the results as judged from repeat observations and objects with very well-determined orbits is similar to previous papers in this series, namely ~3mas in separation and <1{deg} in position angle in most cases. Similarly, the photometric precision remains consistent with previous WIYN speckle data, on average ~0.1mag per observation. Six systems of special interest are discussed.
- ID:
- ivo://CDS.VizieR/J/AJ/143/10
- Title:
- 2008-2009 WIYN speckle observations of binaries. VII.
- Short Name:
- J/AJ/143/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Five hundred thirty-one speckle measures of binary stars are reported. These data were taken mainly during the period 2008 June through 2009 October at the WIYN 3.5m Telescope at Kitt Peak and represent the last data set of single-filter speckle observations taken in the WIYN speckle program prior to the use of the current two-channel speckle camera. The astrometric and photometric precision of these observations is consistent with previous papers in this series: we obtain a typical linear measurement uncertainty of approximately 2.5mas, and the magnitude differences reported have typical uncertainties in the range of 0.1-0.14mag. In combination with measures already in the literature, the data presented here permit the revision of the orbit of A 1634AB (= HIP 76041) and the first determination of visual orbital elements for HDS 1895 (= HIP 65982).
- ID:
- ivo://CDS.VizieR/J/ApJS/182/625
- Title:
- WIYN spectroscopy in the deep SWIRE field
- Short Name:
- J/ApJS/182/625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of spectroscopy using HYDRA on the WIYN 3.5m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24um. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to active galactic nuclei and star formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z<0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10:46:00, +59:01:00 (J2000). Optical sources for spectroscopic observation were selected from an r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20cm detections, 24m detections, galaxies with r<20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice, almost all the galaxies with r<19 were observed including all of the radio sources and most of the 24um sources with r<20 and a sample of radio sources which had fainter optical counterparts on the r-band image.
![To the extent possible under law, the publisher has waived all copyright and related or neighboring rights to the catalogue of astrometric microlensing events. For details, see the `Creative Commons CC0 1.0 Public Domain dedication <http://creativecommons.org/publicdomain/zero/1.0/>`_. Of course, you should still give proper credit when using this data as required by good scientific practice. .. image:: /static/img/cc0.png :alt: [CC0]](/registry-search/?f%5BcapabilityType_facet%5D%5B%5D=Simple+Cone+Search&f%5Brights_facet%5D%5B%5D=To+the+extent+possible+under+law%2C+the+publisher+has+waived+all+copyright+and+related+or+neighboring+rights+to+the+catalogue+of+astrometric+++microlensing+events.++For+details%2C+see+the+%60Creative+Commons+CC0+1.0+Public+Domain+dedication+%3Chttp%3A%2F%2Fcreativecommons.org%2Fpublicdomain%2Fzero%2F1.0%2F%3E%60_.++Of+course%2C+you+should+still+give+proper+credit+when+using+this+data+as+required+by+good+scientific+practice.%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fcc0.png%0A+++%3Aalt%3A+%5BCC0%5D%0A%0A){kind=link}