- ID:
- ivo://CDS.VizieR/J/A+A/449/305
- Title:
- Geneva photometry time series of HD 203664
- Short Name:
- J/A+A/449/305
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We made a seismic study of the young massive beta Cephei star HD 203664 with the goal of constraining its interior structure. Our study is based on a time series of 328 new Geneva 7-colour photometric data of the star spread over 496.8 days. The data confirm the frequency of the dominant mode of the star, which we refined to f_1_=6.02885c/d. The mode has a large amplitude of 37mmag in V and is unambiguously identified as a dipole mode (l=2) from its amplitude ratios and non-adiabatic computations. Besides f_1_, we discovered two additional new frequencies in the star with amplitudes above 4{sigma}: f_2_=6.82902c/d and f_3_=4.81543c/d, or one of their daily aliases. The amplitudes of these two modes are only between 3 and 4mmag, which explains why they were not detected before. Their amplitude ratios are too uncertain for mode identification. We show that the observed oscillation spectrum of HD 203664 is compatible with standard stellar models but that we have insufficient information for asteroseismic inferences. Among the large-amplitude beta Cephei stars, HD 203664 stands out as the only one rotating at a significant fraction of its critical rotation velocity (~40%).
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- ID:
- ivo://CDS.VizieR/VI/102
- Title:
- Geneva stellar evolution tracks and isochrones
- Short Name:
- VI/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This database was created from an updated version of the empirically and semi-empirically calibrated BaSeL library of synthetic stellar spectra of Lejeune et al. (1997, Cat. <J/A+AS/125/229>, 1998, Cat. <J/A+AS/130/65>) and Westera et al. (1999, ASP Conference Series 192, 203-206) to calculate synthetic photometry in the (UBV)_J_(RI)_C_ JHKLL'M, HST-WFPC2, Geneva, and Washington systems for the entire set of non-rotating Geneva stellar evolution models covering masses from 0.4-0.8 to 120-150M_{sun}_ and metallicities Z=0.0004 (1/50Z_{sun}_) to 0.1 (5Z_{sun}_). The results are provided in a database which includes all individual stellar tracks and the corresponding isochrones covering ages from 10^3^yr to 16-20Gyr in time steps of {Delta}logt=0.05dex. The database also includes a new grid of stellar tracks of very metal-poor stars (Z=0.0004) from 0.8-150M_{sun}_ calculated with the Geneva stellar evolution code. The complete stellar grids are tabulated in the files table1.dat (summary), evol.dat (evolutionary models), and in the files ubv.dat, hst.dat, gen.dat and cmt.dat (synthetic colors in the different photometric systems). These grids are also available as mod* files in subdirectories evol, ubv, hst, gen and cmt. The isochrones for the different photometric systems are summarized in the file table2.dat; the parameters of the isochrones are tabulated in the file iso.dat, the detailed isochrones being available as files iso* in the subdirectories ubv, hst, gen and cmt.
- ID:
- ivo://CDS.VizieR/J/A+A/659/L4
- Title:
- Geometric albedo of HD 209458 b
- Short Name:
- J/A+A/659/L4
- Date:
- 02 Mar 2022 07:55:13
- Publisher:
- CDS
- Description:
- We report the detection of the secondary eclipse of the hot Jupiter HD 209458 b in optical/visible light using the CHEOPS space telescope. Our measurement of 20.4^+3.2^_3.3_ parts per million (ppm) translates into a geometric albedo of Ag=0.096+/-0.016. The previously estimated dayside temperature of about 1500K implies that our geometric albedo measurement consists predominantly of reflected starlight and is largely uncontaminated by thermal emission. This makes the present result one of the most robust measurements of Ag for any exoplanet, critical for understanding the atmosphere. Our calculations of the bandpass-integrated geometric albedo demonstrate that the measured value of Ag is consistent with a cloud-free atmosphere, where starlight is reflected via Rayleigh scattering by hydrogen molecules, with water and sodium abundances consistent with stellar metallicity. We predict that the bandpass-integrated TESS geometric albedo is too faint to detect and that a phase curve of HD 209458 b observed by CHEOPS would have a distinct shape associated with Rayleigh scattering if the atmosphere is indeed cloud-free.
7184. Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3 (eDR3)
- ID:
- ivo://org.gavo.dc/gedr3dist/q/main
- Title:
- Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3 (eDR3)
- Short Name:
- gedr3dist.main
- Date:
- 15 Aug 2024 15:17:03
- Publisher:
- The GAVO DC team
- Description:
- We estimate the distance from the Sun to sources in Gaia eDR3 that have parallaxes. We provide two types of distance estimate, together with their corresponding asymmetric uncertainties, using Bayesian posterior density functions that we sample for each source. Our prior is based on a detailed model of the 3D spatial, colour, and magnitude distribution of stars in our Galaxy that includes a 3D map of interstellar extinction. The first type of distance estimate is purely geometric, in that it only makes use of the Gaia parallax and parallax uncertainty. This uses a direction-dependent distance prior derived from our Galaxy model. The second type of distance estimate is photogeometric: in addition to parallax it also uses the source's G-band magnitude and BP-RP colour. This type of estimate uses the geometric prior together with a direction-dependent and colour-dependent prior on the absolute magnitude of the star. Our distance estimate and uncertainties are quantiles, so are invariant under logarithmic transformations. This means that our median estimate of the distance can be used to give the median estimate of the distance modulus, and likewise for the uncertainties. For applications that cannot be satisfied through TAP, you can download a `full table dump`_. .. _full table dump: /gedr3dist/q/download/form
- ID:
- ivo://CDS.VizieR/J/AZh/88/954
- Title:
- Geometry of radio pulsar magnetospheres
- Short Name:
- J/AZh/88/954
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Data on the profiles and polarization of the 10- and 20-cm emission of radio pulsars are used to calculate the angle {beta} between the rotational axis of the neutron star and its magnetic moment. It is shown that, for these calculations, it is sufficient to use catalog values of the pulse width at the 10% level W10, since the broadening of the observed pulses due to the transition to the full width W0 and narrowing of the pulses associated with the emission of radiation along tangents to the field lines approximately cancel each other out. The angles {beta}1 are calculated for 283 pulsars at 20cm and 132 pulsars at 10cm, assuming that the line of sight passes through the center of the emission cone.
- ID:
- ivo://geops.ipsl/tap
- Title:
- GEOPS/IPSL DaCHS Server TAP service
- Short Name:
- GEOPS TAP
- Date:
- 17 Jul 2024 15:25:16
- Publisher:
- GEOPS/IPSL
- Description:
- The GEOPS/IPSL DaCHS Server's TAP end point. The Table Access Protocol (TAP) lets you execute queries against our database tables, inspect various metadata, and upload your own data. It is thus the VO's premier way to access public data holdings. Tables exposed through this endpoint include: epn_core from the exotopo schema, epn_core from the pretharsis schema, columns, groups, key_columns, keys, schemas, tables from the tap_schema schema.
7187. GEOS RR Lyr survey
- ID:
- ivo://CDS.VizieR/J/other/IBVS/5767
- Title:
- GEOS RR Lyr survey
- Short Name:
- J/other/IBVS/576
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present here the sixth list of light maxima of RR Lyrae stars from the GEOS RR Lyr Survey, a GEOS program (http://www.upv.es/geos/) (Boninsegna et al., 2002ASPC..259..166B) of automated observations of RR Lyr stars started in January 2004.
- ID:
- ivo://CDS.VizieR/II/55
- Title:
- Gershberg Flare Star Catalogue
- Short Name:
- II/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog groups the flare stars as presented in the IAU Colloquium 15 (combined Colloquium of Commisions 27 and 42) held at Bamberg 31-Aug to 03-Sep 1971 entitled "New Directions and New Frontiers in Variable Star Research" The following definition of the UV Cet-type variables was given in Kukarkin's General Catalogue of Variable Stars (1969): "dMe stars, sometimes subject to flares with the amplitude from 1 to 6mag. Maximum brightness is attained in seconds or dozens of seconds after the commencement of the flare; the star returns to its normal brightness after several minutes, or dozens of minutes. A typical representative is UV Ceti." Now it is impossible to consider this definition as a quite right because: 1) There are a number of M-dwarf stars affected by the flares similar to the UV Ceti flares, but in their quiet state spectra, no emission lines are observed. For example, BD+43 44A, BD+43 44 B, and SZ UMa, the flare activity of these stars were detected in Crimea; and probably BD-04 4048B is suspected as a flare star by HERBIG. 2) The lower limit of flare amplitude cited in Kukarkin's corresponds to visual observations, but the modern photoelectric observations register flares with amplitudes to 0.02-0.05mag. Therefore we suppose, that UV Cet-type variables are K-M dwarfs, which show quick flares with amplitudes exceeding the observational errors, and duration of the flares are from a few seconds up to a few hundred minutes. The "catalog" file includes only such variable K-M dwarf stars, for which existing observations allow to construct flare light curves. All stars in "catalog", except V371 Ori, have photoelectric flare light curves. The strong flare of V371 Ori was observed in radio region, but simultaneous optical observations were carried out photographically and visually only.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A112
- Title:
- GES iDR4 Mg-Al anticorrelation in GCs
- Short Name:
- J/A+A/601/A112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Gaia-ESO Survey iDR4 data to explore the Mg-Al anti-correlation in globular clusters, that were observed as calibrators, as a demonstration of the quality of Gaia-ESO Survey data and analysis. The results compare well with the available literature, within 0.1~[-] or less, after a small (compared to the Minternal spreads) offset between the UVES and the GIRAFFE data of 0.10-0.15dex was taken into account. In particular, we present for the first time data for NGC 5927, one of the most metal-rich globular clusters studied in the literature so far with [Fe/H]=-0.49dex, that was included to connect with the open cluster regime in the Gaia-ESO Survey internal calibration. The extent and shape of the Mg-Al anti-correlation provide strong constraints on the multiple population phenomenon in globular clusters. In particular, we studied the dependency of the Mg-Al anti-correlation extension with metallicity, present-day mass, and age of the clusters, using GES data in combination with a large set of homogenized literature measurements. We find a dependency with both metallicity and mass, that is evident when fitting for the two parameters simultaneously, but no significant dependency with age. We confirm that the Mg-Al anti-correlation is not seen in all clusters, but disappears for the less massive or most metal-rich ones. We also use our dataset to see whether a normal anti-correlation would explain the low [Mg/{alpha}] observed in some extragalactic globular clusters, but find that none of the clusters in our sample can reproduce it, and more extreme chemical compositions (like the one of NGC 2419) would be required. We conclude that GES iDR4 data already meet the requirements set by the main survey goals, and can be used to study in detail globular clusters even if the analysis procedures were not specifically designed for them.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A95
- Title:
- GES: multi-line spectroscopic binary candidates
- Short Name:
- J/A+A/608/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Gaia-ESO Survey (GES) is a large spectroscopic survey that provides a unique opportunity to study the distribution of spectroscopic multiple systems among different populations of the Galaxy. Aims. Our aim is to detect binarity/multiplicity for stars targeted by the GES from the analysis of the cross-correlation functions (CCFs) of the GES spectra with spectral templates. We developed a method based on the computation of the CCF successive derivatives to detect multiple peaks and determine their radial velocities, even when the peaks are strongly blended. The parameters of the detection of extrema (DOE) code have been optimized for each GES GIRAFFE and UVES setup to maximize detection. The DOE code therefore allows to automatically detect multiple line spectroscopic binaries (SBn, n>=2). We apply this method on the fourth GES internal data release and detect 354 SBn candidates (342 SB2, 11 SB3, and even one SB4), including only nine SBs known in the literature. This implies that about 98% of these SBn candidates are new because of their faint visual magnitude that can reach V=19. Visual inspection of the SBn candidate spectra reveals that the most probable candidates have indeed a composite spectrum. Among the SB2 candidates, an orbital solution could be computed for two previously unknown binaries: CNAME 06404608+0949173 (known as V642 Mon) in NGC 2264 and CNAME 19013257-0027338 in Berkeley 81 (Be 81). A detailed analysis of the unique SB4 (four peaks in the CCF) reveals that CNAME 08414659-5303449 (HD 74438) in the open cluster IC 2391 is a physically bound stellar quadruple system. The SB candidates belonging to stellar clusters are reviewed in detail to discard false detections. We suggest that atmospheric parameters should not be used for these system components; SB-specific pipelines should be used instead. Our implementation of an automatic detection of spectroscopic binaries within the GES has allowed the efficient discovery of many new multiple systems. With the detection of the SB1 candidates that will be the subject of a forthcoming paper, the study of the statistical and physical properties of the spectroscopic multiple systems will soon be possible for the entire GES sample.