- ID:
- ivo://CDS.VizieR/J/A+A/357/471
- Title:
- BV and proper motions in NGC 1960 & NGC 2194
- Short Name:
- J/A+A/357/471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD photometry and proper motion studies of the two open star clusters NGC 1960 (M 36) and NGC 2194. Fitting isochrones to the colour magnitude diagrams, for NGC 1960 we found an age of 16Myr and a distance of roughly 1300 pc and for NGC 2194 550Myr and 2900pc, respectively. We combined membership determination by proper motions and statistical field star subtraction to derive the initial mass function of the clusters and found slopes of -1.23+/-0.17 for NGC 1960 and -1.33+/-0.29 for NGC 2194. Compared to other IMF studies of the intermediate mass range, these values indicate shallow mass functions. These tables present the complete data of the photometry (Tables 2 and 3) and the proper motion studies (Tables 7 and 9) of the two clusters.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/484/609
- Title:
- BVI photometry and proper motions in M67
- Short Name:
- J/A+A/484/609
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The solar-age open cluster M 67 (C0847+ 120, NGC 2682) is a touchstone in studies of the old Galactic disk. Despite its outstanding role, the census of cluster membership for M 67 at fainter magnitudes and their properties are not well-established. Using proprietary and archival ESO data, we have obtained astrometric, photometric, and radial velocities of stars in a 34x33arcmin^2^ field centered on the old open cluster M 67. The two-epoch archival observations separated by 4-years and acquired with the Wide-Field Imager at the 2.2m MPG/ ESO telescope were reduced with our new astrometric techniques, as described in the first paper in this series (Anderson et al., 2006A&A...454.1029A). The same observations served to derive calibrated BVI photometry in M 67. Radial velocities were measured using the archival and new spectroscopic data obtained at the VLT.
- ID:
- ivo://CDS.VizieR/J/A+A/505/1129
- Title:
- BVRIJHK and proper motions in NGC 6253
- Short Name:
- J/A+A/505/1129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric and astrometric catalog of 187963 stars located in the field around the old super-metal-rich Galactic open cluster NGC 6253.
- ID:
- ivo://CDS.VizieR/J/ApJS/133/119
- Title:
- Calan-ESO proper-motion catalog
- Short Name:
- J/ApJS/133/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Calan-ESO Proper-Motion Catalog (CE Catalog) contains 542 stars with proper motions >=0.2"/yr, identified in 14 ESO areas in the southern hemisphere. Proper motions were measured from red IIIa-F plates taken 6-16yr apart. Comparing the CE catalog with the Luyten and the Luyten half-second catalogs, we find that both suffer from incompleteness, which is particularly serious (<~40% complete) for m_R_>~13, where many of the astrophysically interesting object can be found. Proper motions, coordinates, estimated magnitudes, and finding charts for all objects in the catalog are provided
- ID:
- ivo://CDS.VizieR/J/ApJ/790/164
- Title:
- Candidate bulge WDs in the SWEEPS field
- Short Name:
- J/ApJ/790/164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Hubble Space Telescope data of the low-reddening Sagittarius window in the Galactic bulge. The Sagittarius Window Eclipsing Extrasolar Planet Search field (~3'x3'), together with three more Advanced Camera for Surveys and eight Wide-Field Camera 3 fields, were observed in the F606W and F814W filters, approximately every two weeks for 2 yr, with the principal aim of detecting a hidden population of isolated black holes and neutron stars through astrometric microlensing. Proper motions were measured with an accuracy of ~0.1 mas/yr (~4 km/s) at F606W ~25.5 mag, and better than ~0.5 mas/yr (~20 km/s) at F606W ~28 mag, in both axes. Proper-motion measurements allowed us to separate disk and bulge stars and obtain a clean bulge color-magnitude diagram. We then identified for the first time a white dwarf (WD) cooling sequence in the Galactic bulge, together with a dozen candidate extreme horizontal branch stars. The comparison between theory and observations shows that a substantial fraction of the WDs (~30%) are systematically redder than the cooling tracks for CO-core H-rich and He-rich envelope WDs. This evidence would suggest the presence of a significant number of low-mass WDs and WD-main-sequence binaries in the bulge. This hypothesis is further supported by the finding of two dwarf novae in outburst, two short-period (P <~ 1 day) ellipsoidal variables, and a few candidate cataclysmic variables in the same field.
- ID:
- ivo://CDS.VizieR/J/other/Sci/292.698
- Title:
- Candidate halo dark matter
- Short Name:
- J/other/Sci/292.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Milky Way galaxy contains a large, spherical component which is believed to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this "dark matter" may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the galaxy itself. We conducted a survey to find faint, cool white dwarfs with large space velocities, indicative of their membership in the galaxy's spherical halo component. The survey reveals a substantial, directly observed population of old white dwarfs, too faint to be seen in previous surveys. This newly discovered population accounts for at least 2 percent of the halo dark matter. It provides a natural explanation for the indirect observations, and represents a direct detection of galactic halo dark matter.
- ID:
- ivo://CDS.VizieR/J/A+A/635/L3
- Title:
- Candidate member stars of the Sagittarius stream
- Short Name:
- J/A+A/635/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to measure the proper motion along the Sagittarius stream, which is the missing piece in determining its full 6D phase space coordinates. We conduct a blind search of over-densities in proper motion from the Gaia second data release (DR2) in a broad region around the Sagittarius stream by applying wavelet transform techniques. We find that for most of the sky patches, the highest intensity peaks delineate the path of the Sagittarius stream. The 1500 peaks identified depict a continuous sequence spanning almost 2pi in the sky, only obscured when the stream crosses the Galactic disk. Altogether, around 100000 stars potentially belong to the stream as indicated by a coarse inspection of the color-magnitude diagrams. From these stars, we determine the proper motion along the Sagittarius stream, making it the proper-motion sequence with the largest span and continuity ever measured for a stream. A first comparison with existing N-body models of the stream reveals some discrepancies, especially near the pericenter of the trailing arm and an underestimation of the total proper motion for the leading arm. Our study provides a starting point for determining the variation of the population of stars along the stream, the distance to the stream from the red clump stars, and the solar motion. It also permits much more accurate measurement of the Milky Way potential.
- ID:
- ivo://CDS.VizieR/J/other/KFNT/23.102
- Title:
- Candidate Red Clump stars in the Tycho-2
- Short Name:
- J/other/KFNT/23.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalogue of 60910 local stars brighter than Ks=8.2mag, which were assigned to be the most probable Red Clump candidates from Ks-band reduced proper motions. The catalogue is the result of analysis of combined Tycho-2 and 2MASS data selected in (J-Ks) interval from 0.5 to 0.8mag. It includes Tycho-2, Hipparcos and 2MASS numbers, equatorial coordinates J2000.0, proper motions and their standard errors, Tycho-2 B and V magnitudes, 2MASS J, H, Ks magnitudes, and Red Clump probabilities. All astrometric data were extracted from the Tycho-2 main catalogue; photometric data were extracted from the Tycho-2 and 2MASS catalogues. Red Clump probabilities were calculated by means of maximum-likelihood method based on Ks-band reduced proper motions. The catalogue provides data listed in order of right ascension increasing. About 85% of the sample stars are proved may be actual Red Clump giants as resulted from both Ks-band absolute magnitude analysis and the MK spectral classification.
- ID:
- ivo://CDS.VizieR/J/MNRAS/413/1581
- Title:
- Candidate subdwarfs and white dwarfs
- Short Name:
- J/MNRAS/413/1581
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometry from the Two-Micron All-Sky Survey (2MASS), United States Naval Observatory CCD Astrograph Catalog (UCAC3) and SuperCosmos catalogues, together with proper motions from the Tycho-2, Kharkiv Proper Motions (XPM) and UCAC3 catalogues, is used to select all-sky samples of 28 candidate white dwarfs, 1826 evolved and 7641 unevolved subdwarfs for R from 9-17mag. The samples are separated from main-sequence stars with an admixture of less than 10 per cent, owing to an analysis of the distribution of the stars in colour index versus reduced proper-motion diagrams for various latitudes using related Monte Carlo simulations. It is shown that the XPM and UCAC3 catalogues have the same level of proper-motion accuracy. Most of the selected stars have at least six-band photometry. This allows us to eliminate some admixtures and reveal some binaries. Empirical calibrations of absolute magnitude versus colour index and reduced proper motion for Hipparcos stars give us distances and a three-dimensional (3D) distribution for all the selected stars. It is shown that the subdwarf samples are almost complete for the Tycho-2 stars, i.e. to 11mag or 150pc from the Sun. For fainter stars from the XPM and UCAC3 catalogues, the subdwarf samples are complete only to 20-60 per cent because of the selection method and incompleteness of the catalogues.
- ID:
- ivo://CDS.VizieR/J/ApJ/883/8
- Title:
- Cand. young OB stars from GALEX & Gaia DR2
- Short Name:
- J/ApJ/883/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combine Galaxy Evolution Explorer and Gaia DR2 catalogs to track star formation in the outskirts of our Galaxy. Using photometry, proper motions, and parallaxes we identify a structure of ~300 OB-type candidates located between 12 and 15kpc from the Galactic center that are kinematically cold. The structure is located between l=120{deg} and 200{deg}, above the plane up to ~700pc and below the plane to ~1kpc. The bulk motion is disklike; however, we measure a mean upward vertical motion of 5.7+/-0.4km/s, and a mean outward radial motion of between 8 and 16km/s. The velocity dispersion along the least dispersed of its proper-motion axes (perpendicular to the Galactic disk) is 6.0+/-0.3km/s, confirming the young age of this structure. While spatially encompassing the outer spiral arm of the Galaxy, this structure is not a spiral arm. Its explanation as the Milky Way warp is equally unsatisfactory. The structure's vertical extent, mean kinematics, and asymmetry with respect to the plane indicate that its origin is more akin to a wobble generated by a massive satellite perturbing the Galaxy's disk. The mean stellar ages in this outer structure indicate the event took place some 200Myr ago.
