- ID:
- ivo://CDS.VizieR/J/MNRAS/462/2295
- Title:
- 25 parsec local white dwarf population
- Short Name:
- J/MNRAS/462/2295
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have extended our detailed survey of the local white dwarf population from 20 to 25pc, effectively doubling the sample volume, which now includes 232 stars. In the process, new stars within 20 pc have been added, a more uniform set of distance estimates as well as improved spectral and binary classifications are available. The present 25pc sample is estimated to be about 68 per cent complete (the corresponding 20pc sample is now 86 per cent complete). The space density of white dwarfs is unchanged at 4.8+/-0.5x10^-3^pc^-3^. This new study includes a white dwarf mass distribution and luminosity function based on the 232 stars in the 25pc sample. We find a significant excess of single stars over systems containing one or more companions (74 per cent versus 26 per cent). This suggests mechanisms that result in the loss of companions during binary system evolution. In addition, this updated sample exhibits a pronounced deficiency of nearby 'Sirius-like' systems. 11 such systems were found within the 20pc volume versus only one additional system found in the volume between 20 and 25pc. An estimate of white dwarf birth rates during the last ~8Gyr is derived from individual remnant cooling ages. A discussion of likely ways new members of the local sample may be found is provided.
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- ID:
- ivo://CDS.VizieR/J/A+A/650/A201
- Title:
- 10 parsec sample in the Gaia era
- Short Name:
- J/A+A/650/A201
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The nearest stars provide a fundamental constraint for our understanding of stellar physics and the Galaxy. The nearby sample serves as an anchor where all objects can be seen and understood with precise data. This work is triggered by the most recent data release of the astrometric space mission Gaia and uses its unprecedented high precision parallax measurements to review the census of objects within 10pc. The first aim of this work was to compile all stars and brown dwarfs within 10pc observable by Gaia and compare it with the Gaia Catalogue of Nearby Stars as a quality assurance test. We complement the list to get a full 10 pc census, including bright stars, brown dwarfs, and exoplanets. We started our compilation from a query on all objects with a parallax larger than 100 mas using the Set of Identifications, Measurements, and Bibliography for Astronomical Data database (SIMBAD). We completed the census by adding companions, brown dwarfs with recent parallax measurements not in SIMBAD yet, and vetted exoplanets. The compilation combines astrometry and photometry from the recent Gaia Early Data Release 3 with literature magnitudes, spectral types, and line-of-sight velocities. We give a description of the astrophysical content of the 10pc sample. We find a multiplicity frequency of around 27%. Among the stars and brown dwarfs, we estimate that around 61% are M stars and more than half of the M stars are within the range from M3.0 V to M5.0 V. We give an overview of the brown dwarfs and exoplanets that should be detected in the next Gaia data releases along with future developments. We provide a catalogue of 540 stars, brown dwarfs, and exoplanets in 339 systems, within 10pc from the Sun. This list is as volume-complete as possible from current knowledge and it provides benchmark stars that can be used, for instance, to define calibration samples and to test the quality of the forthcoming Gaia releases. It also has a strong outreach potential.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/L11
- Title:
- Passive spiral galaxy cand. multi-phot.
- Short Name:
- J/MNRAS/462/L11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified a population of passive spiral galaxies from photometry and integral field spectroscopy. We selected z<0.035 spiral galaxies that have WISE colours consistent with little mid-infrared emission from warm dust. Matched aperture photometry of 51 spiral galaxies in ultraviolet, optical and mid-infrared show these galaxies have colours consistent with passive galaxies. Six galaxies form a spectroscopic pilot study and were observed using the Wide-Field Spectrograph (WiFeS) to check for signs of nebular emission from star formation. We see no evidence of substantial nebular emission found in previous red spiral samples. These six galaxies possess absorption line spectra with 4000{AA} breaks consistent with an average luminosity-weighted age of 2.3Gyr. Our photometric and IFU spectroscopic observations confirm the existence of a population of local passive spiral galaxies, implying that transformation into early-type morphologies is not required for the quenching of star formation.
- ID:
- ivo://CDS.VizieR/J/AJ/162/100
- Title:
- PAST. II. LAMOST-Gaia-Kepler catalog of 35835 stars
- Short Name:
- J/AJ/162/100
- Date:
- 14 Mar 2022 06:40:51
- Publisher:
- CDS
- Description:
- The Kepler telescope has discovered over 4000 planets (candidates) by searching ~200000 stars over a wide range of distance (order of kpc) in our Galaxy. Characterizing the kinematic properties (e.g., Galactic component membership and kinematic age) of these Kepler targets (including the planet candidate hosts) is the first step toward studying Kepler planets in the Galactic context, which will reveal fresh insights into planet formation and evolution. In this paper, the second part of the Planets Across the Space and Time (PAST) series, by combining the data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Gaia and then applying the revised kinematic methods from PAST I, we present a catalog of kinematic properties (i.e., Galactic positions, velocities, and the relative membership probabilities among the thin disk, thick disk, Hercules stream, and the halo) as well as other basic stellar parameters for 35835 Kepler stars. Further analyses of the LAMOST-Gaia-Kepler catalog demonstrate that our derived kinematic age reveals the expected stellar activity-age trend. Furthermore, we find that the fraction of thin (thick) disk stars increases (decreases) with the transiting planet multiplicity (N_p_=0,1,2 and3+) and the kinematic age decreases with N_p_, which could be a consequence of the dynamical evolution of planetary architecture with age. The LAMOST-Gaia-Kepler catalog will be useful for future studies on the correlations between the exoplanet distributions and the stellar Galactic environments as well as ages.
- ID:
- ivo://CDS.VizieR/J/A+A/591/A14
- Title:
- PCF, SpecB or SDSSB asteroids parameters
- Short Name:
- J/A+A/591/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- B-type asteroids constitute a peculiar spectral class within the C-complex. Previous work has pointed out the difference between the visible geometric albedos of B-types and those of the Pallas collisional family (PCF), whose few members with observed spectra are B-types (one exception out of eight objects). This has been interpreted as being due to compositional differences. However, the PCF members are typically smaller than the spectroscopically classified B-types, and the following possibilities have not been ruled out: the albedo differences might be related to a size-albedo dependence and/or to the generally larger errors of the WISE data and best-fitting values of the derived parameters expected for smaller objects. We compare albedos and beaming parameters of PCF members and B-types of similar sizes and re-examine our conclusion on the different composition of the PCF. By modelling their WISE/NEOWISE data, we derived sizes and albedos of all objects whose Sloan Digital Sky Survey reflectances are similar to the typical B-type reflectance spectra. In particular, we derived the so-called infrared beaming parameters (eta), effective diameters (D), and corresponding visible geometric albedos (pV), and studied their value distributions.
- ID:
- ivo://CDS.VizieR/J/other/Ap/49.450
- Title:
- Peculiar velocities of 2MFGC spirals
- Short Name:
- J/other/Ap/49.45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 2MFGC catalog we have used contains 18020 galaxies selected from among the extended objects in the 2MASS infrared sky survey as having apparent ratios of the axes b/a<0.3. Most of them are spiral galaxies of later morphological types whose disks are seen almost edge-on. The individual distances to the 2724 2MFGC galaxies with known rotation velocities and radial velocities are determined using a multiparameter infrared Tully-Fisher relation. A list of the distances and peculiar velocities of these galaxies is presented. The collective motion of the 2MFGC galaxies relative to the cosmic microwave background is characterized by a velocity V=199+/-37km/s in the direction l=304+/-11, b=-8+/-8 . Our list is currently the most representative and uniform sample for analyzing non-Hubble motions of galaxies on a scale of ~100Mpc.
- ID:
- ivo://CDS.VizieR/J/PASP/121/1188
- Title:
- Periodic variables in NGC 2301
- Short Name:
- J/PASP/121/1188
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for periodic variables within 4078 time-series light curves and an analysis of the period-color plane for stars in the field of the open cluster NGC 2301. One hundred thirty-eight periodic variables were discovered, of which five are eclipsing binary candidates with unequal minima. The remaining 133 periodic variables appear to consist mainly of late-type stars whose variation is due to rotation modulated by star spot activity. The determined periods range from less than a day to over 14 days and have nearly unreddened B-R colors in the range of 0.8 to 2.8. The Barnes (2003ApJ...586..464B) interpretation of the period-color plane of late type stars is tested with our data. Our data did not show distinct I and C sequences, likely due to nonmember field stars contaminating in the background, as we estimate the total contamination to be 43%. Using different assumptions, the gyrochronological age of the cluster is calculated to be 210+/-25Myr, which falls in the range of age values (164-250Myr) determined by previous studies. Finally, we present evidence which nullifies the earlier suggestion that two of the variable stars in NGC 2301 might be white dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJS/241/35
- Title:
- Period-luminosity relations of RSGs in M33 & M31
- Short Name:
- J/ApJS/241/35
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- Based on previously selected preliminary samples of red supergiants (RSGs) in M33 and M31, the foreground stars and luminous asymptotic giant branch stars are further excluded, which leads to the samples of 717 RSGs in M33 and 420 RSGs in M31. With the time-series data from the Intermediate Palomar Transient Factory survey spanning nearly 2000 days, the period and amplitude of RSGs are analyzed. According to the light-curve characteristics, they are classified into four categories in which 84 and 56 objects in M33 and M31, respectively, are semi-regular variables. For these semi-regular variables, the pulsation mode is identified by comparing with the theoretical model, which yielded 19 (7) sources in the first overtone mode in M33 (M31), and the other 65 (49) RSGs in M33 (M31) in the fundamental mode. The period-luminosity (P-L) relation is analyzed for the RSGs in the fundamental mode. The P-L relation is found to be tight in the infrared, i.e., the Two Mircon All-Sky Survey (2MASS) JHK_S_ bands and the short-wavelength bands of Spitzer. Meanwhile, the inhomogeneous extinction causes the P-L relation scattering in the V band, and the dust emission causes the less tight P-L relation in the Spitzer/[8.0] and [24] bands. The derived P-L relations in the 2MASS/K_S_ band are in agreement with those of RSGs in the Small Magellanic Cloud, the Large Magellanic Cloud, and the Milky Way within the uncertainty range. It is found that the number ratio of RSGs pulsating in the fundamental mode to the first overtone mode increases with metallicity.
- ID:
- ivo://CDS.VizieR/J/A+A/556/A38
- Title:
- Period-mass-loss rate relation of Miras
- Short Name:
- J/A+A/556/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery that Mira variables with and without absorption lines of the element technetium (Tc) occupy two different regions in a diagram of near- to mid-IR colour versus pulsation period. Tc is an indicator of a recent or ongoing mixing event called the third dredge-up (3DUP), and the near- to mid-IR colour, such as the (K-[22]) colour where [22] is the the 22um band of the WISE space observatory, is an indicator of the dust mass-loss rate of a star. We collected data from the literature about the Tc content, pulsation period, and near- and mid-IR magnitudes of more than 190 variable stars on the asymptotic giant branch (AGB) to which Miras belong. The sample is naturally biased towards optical AGB stars, which have low to intermediate (dust) mass-loss rates.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1459
- Title:
- Period of M15 variable stars
- Short Name:
- J/AJ/135/1459
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new BVI CCD photometry for variables in the globular cluster M15. Our photometry was obtained using both the image subtraction package ISIS and DAOPHOT/ALLFRAME. The data were acquired in 2001 on two observing runs on 11 observing nights using the 2m telescope of the Bulgarian National Astronomical Observatory "Rozhen" with a Photometrics CCD camera. For 39 previously known variables, we present a period for the first time, and improved periods were obtained for many previously known variables. Fourteen new variables are reported. We present updated Bailey diagrams for the cluster, and discuss its Oosterhoff classification. Although many of M15's RRab pulsators fall at an intermediate locus between Oosterhoff types I and II (OoII) in the Bailey diagram, we argue that M15 is indeed a bona fide OoII globular cluster.
