- ID:
- ivo://CDS.VizieR/J/ApJ/850/137
- Title:
- ISLAndS project. III. Variable stars
- Short Name:
- J/ApJ/850/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a census of variable stars in six M31 dwarf spheroidal satellites observed with the Hubble Space Telescope. We detect 870 RR Lyrae (RRL) stars in the fields of And I (296), II (251), III (111), XV (117), XVI (8), and XXVIII (87). We also detect a total of 15 Anomalous Cepheids, three eclipsing binaries, and seven field RRL stars compatible with being members of the M31 halo or the Giant Stellar Stream. We derive robust and homogeneous distances to the six galaxies using different methods based on the properties of the RRL stars. Working with the up-to-date set of Period-Wesenheit (I, B-I) relations published by Marconi et al., we obtain distance moduli of {mu}0=[24.49, 24.16, 24.36, 24.42, 23.70, 24.43]mag (respectively), with systematic uncertainties of 0.08mag and statistical uncertainties <0.11mag. We have considered an enlarged sample of 16 M31 satellites with published variability studies, and compared their pulsational observables (e.g., periods and amplitudes) with those of 15 Milky Way satellites for which similar data are available. The properties of the (strictly old) RRL in both satellite systems do not show any significant difference. In particular, we found a strikingly similar correlation between the mean period distribution of the fundamental RRL pulsators (RRab) and the mean metallicities of the galaxies. This indicates that the old RRL progenitors were similar at the early stage in the two environments, suggesting very similar characteristics for the earliest stages of evolution of both satellite systems.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/136/631
- Title:
- IUE absorption toward 164 early-type stars
- Short Name:
- J/ApJS/136/631
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of Galactic interstellar AlIII, SiIV, and CIV absorption recorded in high-resolution archival ultraviolet spectra of 164 hot early-type stars observed by the International Ultraviolet Explorer (IUE) satellite. The objects studied were drawn from the list of hot stars scheduled to be observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite as part of observing programs designed to investigate absorption by OVI in the Galactic disk and halo. Multiple IUE echelle-mode integrations have been combined to produce a single ultraviolet (1150-1900{AA}) spectrum of each star with a spectral resolution of ~25km/s (FWHM). Selected absorption-line profiles are presented for each star along with plots of the apparent column density per unit velocity for each line of the AlIII, SiIV, and CIV doublets. We report absorption-line equivalent widths, absorption velocities, and integrated column densities based on the apparent optical depth method of examining interstellar absorption lines. We also determine column densities and Doppler parameters from single-component curve-of-growth analyses. The scientific analysis of these observations will be undertaken after the FUSE satellite produces similar measurements for absorption by interstellar OIV, FeIII, SIII, and other ions.
- ID:
- ivo://CDS.VizieR/J/ApJS/93/211
- Title:
- IUE survey of H I Ly{alpha} absorption. I.
- Short Name:
- J/ApJS/93/211
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure Galactic interstellar neutral hydrogen column densities by analyzing archival interstellar Ly{alpha} absorption line data toward 554 B2 and hotter stars observed at high resolution with the IUE satellite. This study more than doubles the number of lines of sight with measures of N(H I) based on Ly{alpha}. We have included the scattered light background correction algorithm of Bianchi and Bohlin (1984A&A...134...31B) in our data reduction. We use the correlation between the Balmer discontinuity [c_1_] index and the stellar Ly{alpha} absorption in order to assess the effects of stellar Ly alpha contamination. Approximately 40% of the B stars with measured [c_1_] index, exhibit serious stellar Ly{alpha} contamination. Table 1 contains the derived values of the interstellar N(H I) for 393 stars with at most small amounts of stellar contamination. Table 2 lists the observed values of total N(H I) for 161 stars with suspected stellar Ly alpha contamination and/or uncertain stellar parameters.
- ID:
- ivo://CDS.VizieR/J/AcA/54/347
- Title:
- IVB mag of LMC ellipsoidal variables
- Short Name:
- J/AcA/54/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the OGLE-II and OGLE-III photometry of red giants in the Large Magellanic Cloud to select and study objects revealing ellipsoidal variability. We detected 1546 candidates for long period ellipsoidal variables and 121 eclipsing binary systems with clear ellipsoidal modulation.
- ID:
- ivo://CDS.VizieR/J/PAZh/30/605
- Title:
- JHKLM photometry for carbon stars
- Short Name:
- J/PAZh/30/605
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- JHKLM photometry for nine carbon Mira stars, 18 carbon semiregular variables and 2 oxygen Mira stars are provided.
- ID:
- ivo://CDS.VizieR/J/AJ/105/1962
- Title:
- K and M stars photometry
- Short Name:
- J/AJ/105/1962
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Broadband UBVRI photometry is presented for 687 stars from among the dwarf K and M stars found spectroscopically by Vyssotsky [1958AJ.....63..211V]. Of these, 211 are without previous photometry.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/14
- Title:
- KASI-Yonsei Deep Imaging Survey of Clusters (KYDISC)
- Short Name:
- J/ApJS/237/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the KASI-Yonsei Deep Imaging Survey of Clusters targeting 14 clusters at 0.015<~z<~0.144 using the Inamori Magellan Areal Camera and Spectrograph on the 6.5m Magellan Baade telescope and the MegaCam on the 3.6m Canada-France-Hawaii Telescope. We provide a catalog of cluster galaxies that lists magnitudes, redshifts, morphologies, bulge-to-total ratios, and local density. Based on the 1409 spectroscopically confirmed cluster galaxies brighter than -19.8 in the r band, we study galaxy morphology, color, and visual features generated by galaxy mergers. We see a clear trend between morphological content and cluster velocity dispersion, which was not presented by previous studies using local clusters. Passive spirals are preferentially found in a highly dense region (i.e., cluster center), indicating that they have gone through environmental quenching. In deep images ({mu}_r'_~27mag/arcsec^2^), 20% of our sample shows signatures of recent mergers, which is not expected from theoretical predictions and a low frequency of ongoing mergers in our sample (~4%). Such a high fraction of recent mergers in the cluster environment supports a scenario that the merger events that made the features have preceded the galaxy accretion into the cluster environment. We conclude that mergers affect a cluster population mainly through the preprocessing of recently accreted galaxies.
- ID:
- ivo://CDS.VizieR/IV/34
- Title:
- K2 Ecliptic Plane Input Catalog (EPIC)
- Short Name:
- IV/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The K2 Mission (Howell+, 2014PASP..126..398H) uses the Kepler spacecraft to obtain high-precision photometry over ~80 day campaigns in the ecliptic plane. The Ecliptic Plane Input Catalog (EPIC) provides coordinates, photometry, and kinematics based on a federation of all-sky catalogs to support target selection and target management for the K2 mission.
- ID:
- ivo://CDS.VizieR/J/AJ/143/4
- Title:
- Kepler cycle 1 observations of low-mass stars
- Short Name:
- J/AJ/143/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analyzed Kepler light curves for 849 stars with Teff<=5200K from our Cycle 1 Guest Observer program. We identify six new eclipsing binaries, one of which has an orbital period of 29.91 days and two of which are probably W UMa variables. In addition, we identify a candidate "warm Jupiter" exoplanet. We further examine a subset of 670 sources for variability. Of these objects, 265 stars clearly show periodic variability that we assign to rotation of the low-mass star. At the photometric precision level provided by Kepler, 251 of our objects showed no evidence for variability. We were unable to determine periods for 154 variable objects. We find that 79% of stars with Teff<=5200K are variable. The rotation periods we derive for the periodic variables span the range 0.31days<=Prot<=126.5days. A considerable number of stars with rotation periods similar to the solar value show activity levels that are 100 times higher than the Sun.
- ID:
- ivo://CDS.VizieR/J/ApJ/831/11
- Title:
- KIC 9777062 RVs & asteroseismology in NGC6811
- Short Name:
- J/ApJ/831/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of an eccentric, partially eclipsing long-period (P=19.23 days) binary system KIC 9777062 that contains main-sequence stars near the turnoff of the intermediate-age open cluster NGC 6811. The primary is a metal-lined Am star with a possible convective blueshift to its radial velocities, and one star (probably the secondary) is likely to be a {gamma} Dor pulsator. The component masses are 1.603+/-0.006(stat.)+/-0.016(sys.) and 1.419+/-0.003+/-0.008M_{sun}_, and the radii are 1.744+/-0.004+/-0.002 and 1.544+/-0.002+/-0.002R_{sun}_. The isochrone ages of the stars are mildly inconsistent: the age from the mass-radius combination for the primary (1.05+/-0.05+/-0.09Gyr, where the last quote was systematic uncertainty from models and metallicity) is smaller than that from the secondary (1.21+/-0.05+/-0.15Gyr) and is consistent with the inference from the color-magnitude diagram (1.00+/-0.05Gyr). We have improved the measurements of the asteroseismic parameters {Delta}{nu} and {nu}_max_ for helium-burning stars in the cluster. The masses of the stars appear to be larger (or alternately, the radii appear to be smaller) than predicted from isochrones using the ages derived from the eclipsing stars. The majority of stars near the cluster turnoff are pulsating stars: we identify a sample of 28 {delta} Sct, 15 {gamma} Dor, and 5 hybrid types. We used the period-luminosity relation for high-amplitude {delta} Sct stars to fit the ensemble of the strongest frequencies for the cluster members, finding (m-M)_V_=10.37+/-0.03. This is larger than most previous determinations, but smaller than values derived from the eclipsing binary (10.47+/-0.05).
