- ID:
- ivo://CDS.VizieR/J/A+A/400/939
- Title:
- Stellar parameters of 115 HQS sdB stars
- Short Name:
- J/A+A/400/939
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a spectral analysis of a large sample of subdwarf B stars selected from follow-up observations of candidates from the Hamburg Quasar Survey. Table 4 summarizes the results (effective temperatures, gravities, and helium abundances) of our analysis. Additionally, the equatorial and galactical coordinates, the B magnitudes and extinctions, the derived radial velocities, the absolute visual magnitudes, the distances from earth and from the galactic plane, and the references are given for all programme stars.
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- ID:
- ivo://CDS.VizieR/J/AJ/161/288
- Title:
- Stellar population in M53
- Short Name:
- J/AJ/161/288
- Date:
- 18 Jan 2022
- Publisher:
- CDS
- Description:
- We present results from a study of 94 red giant stars in the globular cluster M53. We use low-resolution spectra to measure the strength of CN and CH features at ~3800 and 4300{AA}, respectively. The strengths of these features are used to classify stars into a CN-enhanced and CN-normal population and to measure C and N abundances in all 94 stars. We find the red giant branch stars to be evenly split between the two populations identified, and observe the presence of CN-enhanced stars on the asymptotic giant branch. In addition, we identify five CH star candidates based on the strength of their CN and CH band features, and the presence of a P-branch in their CH band. We compare our identification of multiple populations to those based on the Na-O anticorrelation and pseudo-color indices in Hubble Space Telescope UV photometry, and find general agreement between all three methods. Our large sample size also allows us to study the radial distribution of each population, and we find that the CN-enhanced population is more centrally concentrated. We use our C and N measurements to compare the evolutionary changes in these elements as a function of magnitude between the two populations, and show that both populations experience similar evolutionary changes to the surface abundances of C and N. Finally, we calculate C+N+O abundances for each population and compare them to similar measurements made in M10; we find that in both clusters, CN-enhanced stars have a slightly enhanced C+N+O ({Delta}(C+N+O)~0.2dex).
- ID:
- ivo://CDS.VizieR/J/AJ/158/14
- Title:
- Stellar populations of globular clusters using APOGEE
- Short Name:
- J/AJ/158/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate aluminum abundance variations in the stellar populations of globular clusters using both literature measurements of sodium and aluminum and APOGEE measurements of nitrogen and aluminum abundances. For the latter, we show that the Payne is the most suitable of the five available abundance pipelines for our purposes. Our combined sample of 42 globular clusters spans approximately 2 dex in [Fe/H] and 1.5 dex in logM_GC_/M_{sun}_. We find no fewer than five globular clusters with significant internal variations in nitrogen and/or sodium with little to no corresponding variation in aluminum, and that the minimum present-day cluster mass for aluminum enrichment in metal-rich systems is logM_GC_/M_{sun}_~4.50+2.17([Fe/H]+1.30). We demonstrate that the slopes of the [Al/Fe] versus [Na/Fe] and [Al/Fe] versus [N/Fe] relations for stars without field-like abundances are approximately log-linearly dependent on both the metallicity and the stellar mass of the globular clusters. In contrast, the relationship between [Na/Fe] and [N/Fe] shows no evidence of such dependencies. This suggests that there were (at least) two classes of non-supernova chemical polluters that were common in the early universe, and that their relative contributions within globular clusters somehow scaled with the metallicity and mass of globular clusters. The first of these classes is predominantly responsible for the CNO and NeNa abundance variations, and likewise the second for the MgAl abundance variations. Particularly striking examples of this dichotomy include 47 Tuc and M4. As an auxiliary finding, we argue that abundance variations among Terzan 5 stars are consistent with it being a normal globular cluster.
- ID:
- ivo://CDS.VizieR/J/AJ/156/217
- Title:
- Stellar properties for M dwarfs in MEarth-South
- Short Name:
- J/AJ/156/217
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar rotation periods are valuable both for constraining models of angular momentum loss and for understanding how magnetic features impact inferences of exoplanet parameters. Building on our previous work in the northern hemisphere, we have used long-term, ground-based photometric monitoring from the MEarth Observatory to measure 234 rotation periods for nearby, southern hemisphere M dwarfs. Notable examples include the exoplanet hosts GJ 1132, LHS 1140, and Proxima Centauri. We find excellent agreement between our data and K2 photometry for the overlapping subset. Among the sample of stars with the highest quality data sets, we recover periods in 66%; as the length of the data set increases, our recovery rate approaches 100%. The longest rotation periods we detect are around 140 days, which we suggest represent the periods that are reached when M dwarfs are as old as the local thick disk (about 9 Gyr).
- ID:
- ivo://CDS.VizieR/III/216
- Title:
- Stellar Radial Velocities 1991-1998
- Short Name:
- III/216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present catalogue is the third version and supersedes the first one (1991-1994) published by Malaroda et al. (2000A&AS..144....1M, Cat. <III/204>). We have revised the issues of the journals listed in Table 1, for the period 1991-1998. It is not a complete list of all journals devoted to astronomical literature, but they are the most important ones and those available at our libraries. We prepared a plain ASCII file with the object identifications as provided by the authors. This file was transferred to the SIMBAD database, and, using the proper formats and filters, we have retrieved the identification for each object according to the rules of SIMBAD. In the same way we have also retrieved: the J2000 coordinates, the V magnitude, and the spectral classification for each object.
- ID:
- ivo://CDS.VizieR/III/249
- Title:
- Stellar radial velocities bibliographic catalog
- Short Name:
- III/249
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The present catalogue is the twelfth version and the continuation of the first one (1991-1994) published by Malaroda et al. (2000A&AS..144....1M). Since the 2005 version, we present the catalogue in a database for helping the search. We have revised the issues of the journals listed in Table 1, for the period 1991-2006June. It is not a complete list of all journals devoted to astronomical literature, but they are the most important ones and those available at our libraries. We prepared a plain ASCII file with the object identifications as provided by the authors. This file was transferred to the SIMBAD database, and, using the proper for mats and filters, we have retrieved the identification for each object according to the rules of SIMBAD. In the same way we have also retrieved: the J2000 coordinates, the V magnitude, and the spectral classification for each object.
- ID:
- ivo://CDS.VizieR/III/204
- Title:
- Stellar radial velocities bibliographic catalog
- Short Name:
- III/204
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a bibliographic catalogue of stellar radial velocities with 13359 entries for stars in the Galaxy and the Magellanic Clouds, obtained from the issues of several journals published in the period 1991-1994. We have tried to follow the structure of previous compilations although we have relied on data retrieved from the SIMBAD database.
- ID:
- ivo://CDS.VizieR/III/47B
- Title:
- Stellar Radial Velocities 0-20 hrs
- Short Name:
- III/47B
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Interim Supplement to the General Catalogue of Stellar Radial Velocities (Evans 1979, ISGCRV) contains radial velocities for stars with right ascensions from O through 20 hours. The ISGCRV is intended as a continuation of the General Catalogue of Stellar Radial Velocities (Wilson 1953, GCRV). The ISGCRV resulted from a literature search and data reduction by D. S. Evans covering approximately the years 1951-1977. It contains adopted velocities on the Mount Wilson system. Unfortunately, the individual mea- surements and the literature references could not be included in this version. Both for this reason, and because the ISGCRV covers only O through 20 hours of right ascension (equinox 1900), the ISGCRV should be used with the Bibliography of Stellar Radial Velocities (Abt and Biggs 1972), or the Bibliographical Star Index Retrieval System (Hill et al. 1984).
- ID:
- ivo://CDS.VizieR/J/AJ/135/2264
- Title:
- Stellar radial velocities in NGC 188
- Short Name:
- J/AJ/135/2264
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our ongoing radial-velocity (RV) survey of the old (7Gyr) open cluster NGC 188. Our WIYN 3.5m data set spans a time baseline of 11 years, a magnitude range of 12<=V<=16.5 (1.18-0.94M_{sun}_), and a 1{deg} diameter region on the sky. With the addition of a Domain Astrophysical Observatory data set we extend our bright limit to V=10.8 and, for some stars, extend our time baseline to 35 years. Our magnitude limits include solar-mass main-sequence stars, subgiants, giants, and blue stragglers (BSs), and our spatial coverage extends radially to 17pc (~13 core radii). For the WIYN data we present a detailed description of our data reduction process and a thorough analysis of our measurement precision of 0.4km/s for narrow-lined stars. We have measured radial velocities for 1046 stars in the direction of NGC 188, and have calculated RV membership probabilities for stars with >=3 measurements, finding 473 to be likely cluster members.
1360. Stellar rotation in M35
- ID:
- ivo://CDS.VizieR/J/ApJ/695/679
- Title:
- Stellar rotation in M35
- Short Name:
- J/ApJ/695/679
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a five month photometric time-series survey for stellar rotation over a 40'x40' field centered on the 150Myr open cluster M35 (=NGC 2168). We report rotation periods for 441 stars within this field and determine their cluster membership and binarity based on a decade-long radial velocity survey, proper-motion measurements, and multiband photometric observations. We find that 310 of the stars with measured rotation periods are late-type members of M35. The distribution of rotation periods for cluster members span more than 2 orders of magnitude from ~0.1 to 15 days, not constrained by the sampling frequency and the timespan of the survey. With an age between the zero-age main sequence and the Hyades, and with ~6 times more rotation periods than measured in the Pleiades, M35 permit detailed studies of early rotational evolution of late-type stars. Nearly 80% of the 310 rotators lie on two distinct sequences in the color-period plane, and define clear relations between stellar rotation period and color (mass). The M35 color-period diagram enables us to determine timescales for the transition between the two rotational states, of ~60Myr and ~140Myr for G and K dwarfs, respectively.