- ID:
- ivo://CDS.VizieR/J/AJ/142/39
- Title:
- Sample of 114 {gamma} Doradus candidates
- Short Name:
- J/AJ/142/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a photometric survey of a complete, volume-limited sample of {gamma} Doradus candidates. The sample was extracted from the Hipparcos catalog and consists of 114 stars with colors and absolute magnitudes within the range of known {gamma} Doradus stars and that also lie within a specified volume of 266600pc^3^. We devoted one year of observing time with our T12 0.8m automatic photometric telescope to acquire nightly observations of the complete sample of stars. From these survey observations, we identify 37 stars with intrinsic variability of 0.002mag or more. Of these 37 variables, 8 have already been confirmed as {gamma} Doradus stars in our earlier papers; we scheduled the remaining 29 variables on our T3 0.4m automatic telescope to acquire more intensive observations over the next two years. As promising new {gamma} Doradus candidates were identified from the photometry, we obtained complementary spectroscopic observations of each candidate with the Kitt Peak coude feed telescope. Analysis of our new photometric and spectroscopic data reveals 15 new {gamma} Doradus variables (and confirms two others), 8 new {delta} Scuti variables (and confirms one other), and 3 new variables with unresolved periodicity. Therefore, of the 114 {gamma} Doradus candidates in our volume-limited sample, we find 25 stars that are new or previously known {gamma} Doradus variables. This results in an incidence of 22% for {gamma} Doradus variability among candidate field stars for this volume of the solar neighborhood. The corresponding space density of {gamma} Doradus stars in this volume of space is 0.094 stars per 103pc^3^ or 94 stars per 106pc^3^. We provide an updated list of 86 bright, confirmed, {gamma} Doradus field stars.
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Search Results
- ID:
- ivo://CDS.VizieR/V/15
- Title:
- SAO and Supplementary Data
- Short Name:
- V/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This SAO catalogue (Smithsonian Astrophysical Observatory Catalogue of 258,997 stars, 1966; see catalog <I/131>), connected to the CSI (Catalogue of Stellar Identifications, see Ochsenbein et al. 1981), enables researchers to retrieve reliable astrophysical data for about 20,000 stars. This includes SAO identifications, CSI identifications, equatorial coordinates (B1950), Galactic coordinates, proper motions, photometric data, spectral classifications, radial velocity, etc. The SAO/HD cross index for about 188,000 stars allows users to find (or enter) the catalog with the HD number of the star. The notes contain detected errors, the value of the trigonometric parallax taken from the Jenkins' (1952, 1963) catalogues, the double star designation ADS or IDS, and the name of the star.
- ID:
- ivo://CDS.VizieR/J/ApJ/598/260
- Title:
- Satellites orbiting isolated galaxies
- Short Name:
- J/ApJ/598/260
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Sloan Digital Sky Survey (SDSS), we probe the halo mass distribution by studying the velocities of satellites orbiting isolated galaxies. In a subsample that covers 2500{deg}^2^ on the sky, we detect about 3000 satellites with absolute blue magnitudes going down to M_B_=-14; most of the satellites have M_B_=-16 to -18, comparable to the magnitudes of M32 and the Magellanic Clouds.
- ID:
- ivo://CDS.VizieR/J/AJ/158/155
- Title:
- SB candidates from the RAVE & Gaia DR2 surveys
- Short Name:
- J/AJ/158/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The combination of the final version of the Radial Velocity Experiment (RAVE) spectroscopic survey data release 6 with radial velocities (RVs) and astrometry from Gaia DR2 (Cat. I/345) allows us to identify and create a catalog of single-lined binary star candidates (SB1), their inferred orbital parameters, and to inspect possible double-lined binary stars (SB2). A probability function for the detection of RV variations is used for identifying SB1 candidates. The estimation of orbital parameters for main-sequence dwarfs is performed by matching the measured RVs with theoretical velocity curves sampling the orbital parameter space. The method is verified by studying a mock sample from the SB 9 catalog (Cat. B/sb9). Studying the boxiness and asymmetry of the spectral lines allows us to identify possible SB2 candidates, while matching their spectra to a synthetic library indicates probable properties of their components. From the RAVE catalog we select 37664 stars with multiple RV measurements and identify 3838 stars as SB1 candidates. Joining RAVE and Gaia DR2 yields 450646 stars with RVs measured by both surveys and 27716 of them turn out to be SB1 candidates, which is an increase by an order of magnitude over previous studies. For main-sequence dwarf candidates we calculate their most probable orbital parameters: orbital periods are not longer than a few years and primary components have masses similar to the solar mass. All our results are available in the electronic version.
- ID:
- ivo://CDS.VizieR/J/A+A/551/L4
- Title:
- SB 290 radial velocity curve
- Short Name:
- J/A+A/551/L4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Hot subdwarf B stars (sdBs) are evolved core helium-burning stars with very thin hydrogen envelopes. To form an sdB, the progenitor has to lose almost all of its hydrogen envelope right at the tip of the red giant branch. In close binary systems, mass transfer to the companion provides the extraordinary mass loss required for their formation. However, apparently single sdBs exist as well, and their formation has been unclear for decades. The merger of helium white dwarfs leading to an ignition of core helium-burning or the merger of a helium core and a low-mass star during the common envelope phase have been proposed. Here we report the discovery of SB 290 as the first apparently single, fast-rotating sdB star located on the extreme horizontal branch, indicating that those stars may form from mergers.
- ID:
- ivo://CDS.VizieR/VII/251
- Title:
- SBS/Zwicky cluster relation
- Short Name:
- VII/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the same area covered by Second Byurakan Survey and CGCG, there are 1677 SBS galaxies, of which 892 are positioned inside the contours of Zwicky clusters. Data on these galaxies and respective clusters are presented in different tables, according to whether they are galaxies which are members of clusters or their substructures, probable or possible members. Projection cases are considered separately.
- ID:
- ivo://CDS.VizieR/J/A+A/341/818
- Title:
- s-Cepheid velocity curves
- Short Name:
- J/A+A/341/818
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The light curves of the first overtone Pop. I Cepheids (s-Cepheids) show a discontinuity in their {phi}_21_ vs. P diagram, near P=3.2day. This feature, commonly attributed to the 2:1 resonance between the first and the fourth overtones ({omega}_4_~2{omega}_1_), is not reproduced by the hydrodynamical models. With the goal of reexamining the resonance hypothesis, we have obtained new CORAVEL radial velocity curves for 14 overtone Cepheids. Together with 10 objects of Krzyt et al. (1999, in prep.), the combined sample covers the whole range of overtone Cepheid periods. The velocity Fourier parameters display a strong characteristic resonant behavior. In striking contrast to photometric ones, they vary smoothly with the pulsation period and show no jump at 3.2day. The existing radiative hydrodynamical models match the velocity parameters very well. The center of the {omega}_4_=2{omega}_1_ resonance is estimated to occur at Pr=4.58+/-0.04day, i.e. at a period considerably longer than previously assumed (3.2day). We identify two new members of the s-Cepheid group: MY Pup and V440 Per.
- ID:
- ivo://CDS.VizieR/J/MNRAS/418/244
- Title:
- SDSS-based Polar Ring Catalogue
- Short Name:
- J/MNRAS/418/244
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxies with polar rings (PRGs) are a unique class of extragalactic objects. Using these, we can investigate a wide range of problems, linked to the formation and evolution of galaxies, and we can study the properties of their dark haloes. The progress that has been made in the study of PRGs has been constrained by the small number of known objects of this type. The Polar Ring Catalogue (PRC) by Whitmore et al. (1990AJ....100.1489W) and their photographic atlas of PRGs and related objects includes 157 galaxies. At present, there are only about two dozen kinematically confirmed galaxies in this PRG class, mostly from the PRC. We present a new catalogue of PRGs, supplementing the PRC and significantly increasing the number of known candidate PRGs. The catalogue is based on the results of the original Galaxy Zoo project. Within this project, volunteers performed visual classifications of nearly a million galaxies from the Sloan Digital Sky Survey (SDSS). Based on the preliminary classifications of the Galaxy Zoo, we viewed more than 40000 images of the SDSS and selected 275 galaxies to include in our catalogue.
- ID:
- ivo://CDS.VizieR/J/ApJ/869/122
- Title:
- SDSS-DR14 and LAMOST DR6 spectra in GD-1 stream
- Short Name:
- J/ApJ/869/122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Combining data from Gaia DR2, SDSS DR14, and LAMOST DR6, we update the fit to model of the properties of the stellar stream GD-1 and find that it has an age of ~13Gyr, [Fe/H] of -2.2+/-0.12, and a distance from the Sun of ~8kpc. We tabulate six-dimensional (6D) phase-space fiducial points along the GD-1 stream orbit over a 90{deg} arc. The fitted orbit shows that the stream has an eccentricity e~0.3, perigalacticon of 14.2kpc, apogalacticon of 27.0kpc, and inclination i~40{deg}. There is evidence along the arc for four candidate stellar overdensities, one candidate gap, two candidate stellar underdensities, and that the stream is cut off at {phi}_1_~2{deg} (in the stream-aligned ({phi}_1_, {phi}_2_) coordinate system of Koposov+ 2010ApJ...712..260K). The spur originating at {phi}_1_~-40{deg} implies stars were pulled away from the stream trace by an encounter (potentially a dark matter subhalo). The narrowest place (FWHM~44.6pc) of the GD-1 trace is at ({phi}_1_, {phi}2^c^)~(-14{deg}, 0.15{deg}), which is ~(178.18{deg}, 52.19{deg}) in (RA, DE), where the progenitor is possibly located. We also find six blue horizontal branch and 10 blue stragglers spectroscopic stars in the GD-1 stream.
- ID:
- ivo://CDS.VizieR/J/ApJ/738/79
- Title:
- SDSS-DR8 BHB stars in the Milky Way's halo
- Short Name:
- J/ApJ/738/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and analyze the positions, distances, and radial velocities for over 4000 blue horizontal-branch (BHB) stars in the Milky Way's halo, drawn from SDSS DR8. We search for position-velocity substructure in these data, a signature of the hierarchical assembly of the stellar halo. Using a cumulative "close pair distribution" as a statistic in the four-dimensional space of sky position, distance, and velocity, we quantify the presence of position-velocity substructure at high statistical significance among the BHB stars: pairs of BHB stars that are close in position on the sky tend to have more similar distances and radial velocities compared to a random sampling of these overall distributions. We make analogous mock observations of 11 numerical halo formation simulations, in which the stellar halo is entirely composed of disrupted satellite debris, and find a level of substructure comparable to that seen in the actually observed BHB star sample. This result quantitatively confirms the hierarchical build-up of the stellar halo through a signature in phase (position-velocity) space. In detail, the structure present in the BHB stars is somewhat less prominent than that seen in most simulated halos, quite possibly because BHB stars represent an older sub-population. BHB stars located beyond 20kpc from the Galactic center exhibit stronger substructure than at r_gc_<20kpc.
