- ID:
- ivo://CDS.VizieR/J/other/RAA/19.64
- Title:
- LAMOST spectroscopic binaries & variable stars
- Short Name:
- J/other/RAA/19.6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- About 786.4 thousand stars were observed by LAMOST twice or more during the first stage of its spectroscopic survey. The radial velocity differences for about 256 thousand targets are larger than 10km/s and they are possible spectroscopic binary or variable candidates (SBVCs). It is shown that most SBVCs are slightly metal poorer than the Sun. There are two peaks in the temperature distribution of SBVCs around 5760K and 4870K, while there are three peaks in the distribution of the gravitational acceleration at 2.461, 4.171 and 4.621cm/s^2^. The locations of SBVCs on the [Fe/H]-T, [Fe/H]-logg, logg-T and H-R diagrams are investigated. It is found that the detected SBVCs could be classified into four groups. The first group has higher logg~4.621 and lower T~4870K which are mainly cool red dwarf binaries. The second group of SBVCs has logg around 4.171cm/s^2^ that includes binaries and pulsating stars such as {delta} Sct and {gamma} Dor variables. The gravitational accelerations of the third group of SBVCs are higher and some of them are below the zero-age main sequence. They may be contact binaries in which the primary components are losing energy to the secondaries in the common envelopes and are at a special stellar evolutionary stage. The last group is composed of giants or supergiants with logg around 2.461cm/s^2^ that may be evolved pulsating stars. One target (C134624.29+333921.2) is confirmed as an eclipsing binary with a period of 0.65-days. A preliminary analysis suggests that it is a detached binary with a mass ratio of 0.46. The primary fills its critical Roche lobe by about 89%, indicating that mass transfer will occur between the two components.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/701/764
- Title:
- Light curves for five M-dwarf stars
- Short Name:
- J/ApJ/701/764
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have derived masses and radii for both components in five short-period single-lined eclipsing binary stars discovered by the TrES wide-angle photometric survey for transiting planets. All these systems consist of a visible F-star primary and an unseen M-star secondary (M_A_>=0.8M_{sun}_, M_B_<=0.45M_{sun}_). The spectroscopic orbital solution combined with a high-precision transit light curve for each system gives sufficient information to calculate the density of the primary star and the surface gravity of the secondary. The masses of the primary stars were obtained using stellar evolution models, which requires accurate determinations of metallicities and effective temperatures.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A7
- Title:
- Li-rich and non-Li-rich K giants RVs
- Short Name:
- J/A+A/639/A7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The origin of the Li-rich K giants is still highly debated. Here, we investigate the incidence of binarity among this family from a nine-year radial-velocity monitoring of a sample of 11 Li-rich K giants using the HERMES spectrograph attached to the 1.2m Mercator Telescope. A sample of 13 non-Li-rich giants (8 of them being surrounded by dust according to IRAS, WISE, and ISO data) was monitored alongside. When compared to the binary frequency in a reference sample of 190K giants (containing 17.4% of definite spectroscopic binaries - SB - and 6.3% of possible spectroscopic binaries - SB?), the binary frequency appears normal among the Li-rich giants (2/11 definite binaries plus 2 possible binaries, or 18.2% SB + 18.2% SB?), after taking account of the small sample size through the hypergeometric probability distribution. Therefore, there appears to be no causal relationship between Li enrichment and binarity. Moreover, there is no correlation between Li enrichment and the presence of circumstellar dust, and the only correlation that could be found between Li enrichment and rapid rotation is that the most Li-enriched K giants appear to be fast-rotating stars. However, among the dusty K giants, the binary frequency is much higher (4/8 definite binaries plus 1 possible binary). The remaining 3 dusty K giants suffer from a radial-velocity jitter, as is expected for the most luminous K giants, which these are.
- ID:
- ivo://CDS.VizieR/J/A+A/626/A128
- Title:
- Main-sequence and subgiant Barium stars
- Short Name:
- J/A+A/626/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Barium (Ba) dwarfs and CH subgiants are the less evolved analogues of Ba and CH giants. They are F- to G-type main-sequence stars polluted with heavy elements by their binary companions when the companion was on the asymptotic giant branch (AGB). This companion is now a white dwarf that in most cases cannot be directly detected. We present a large systematic study of 60 objects classified as Ba dwarfs or CH subgiants. Combining radial-velocity measurements from HERMES and SALT high-resolution spectra with radial-velocity data from CORAVEL and CORALIE, we determine the orbital parameters of 27 systems. We also derive their masses by comparing their location in the Hertzsprung-Russell diagram with evolutionary models. We confirm that Ba dwarfs and CH subgiants are not at different evolutionary stages, and that they have similar metallicities, despite their different names. Additionally, Ba giants appear significantly more massive than their main-sequence analogues. This is likely due to observational biases against the detection of hotter main- sequence post-mass-transfer objects. Combining our spectroscopic orbits with the Hipparcos astrometric data, we derive the orbital inclination and the mass of the WD companion for four systems. Since this cannot be done for all systems in our sample yet (but should be possible with upcoming Gaia data releases), we also analyse the mass-function distribution of our binaries. We can model this distribution with very narrow mass distributions for the two components and random orbital orientations on the sky. Finally, based on BINSTAR evolutionary models, we suggest that the orbital evolution of low-mass Ba systems can be affected by a second phase of interactions along the red giant branch of the Ba star, which impact the eccentricities and periods of the giants.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1015
- Title:
- MAP observations of the position of Procyon
- Short Name:
- J/AJ/131/1015
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the analysis of observations of Procyon obtained with the Multichannel Astrometric Photometer during the years 1986-2004. While the results significantly increase the precision of the estimated characteristics of the components of the system, they are generally in good agreement with the most recent studies.
- ID:
- ivo://CDS.VizieR/J/AJ/149/26
- Title:
- Massive binary stars from an HST/FGS survey
- Short Name:
- J/AJ/149/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an all-sky survey made with the Fine Guidance Sensor on the Hubble Space Telescope to search for angularly resolved binary systems among massive stars. The sample of 224 stars is comprised mainly of Galactic O- and B-type stars and luminous blue variables, plus a few luminous stars in the Large Magellanic Cloud. The FGS TRANS mode observations are sensitive to the detection of companions with an angular separation between 0.01'' and 1.0'' and brighter than {delta}m=5. The FGS observations resolved 52 binary and 6 triple star systems and detected partially resolved binaries in 7 additional targets (43 of these are new detections). These numbers yield a companion detection frequency of 29% for the FGS survey. We also gathered literature results on the numbers of close spectroscopic binaries and wider astrometric binaries among the sample, and we present estimates of the frequency of multiple systems and the companion frequency for subsets of stars residing in clusters and associations, field stars, and runaway stars. These results confirm the high multiplicity fraction, especially among massive stars in clusters and associations. We show that the period distribution is approximately flat in increments of logP. We identify a number of systems of potential interest for long-term orbital determinations, and we note the importance of some of these companions for the interpretation of the radial velocities and light curves of close binaries that have third companions.
- ID:
- ivo://CDS.VizieR/J/A+A/584/A5
- Title:
- Massive LMC stars AAOmega spectroscopy
- Short Name:
- J/A+A/584/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectral classifications from optical spectroscopy of 263 massive stars in the north-eastern region of the Large Magellanic Cloud. The observed two-degree field includes the massive 30 Doradus star-forming region, the environs of SN1987A, and a number of star-forming complexes to the south of 30 Dor. These are the first classifications for the majority (203) of the stars and include eleven double-lined spectroscopic binaries. The sample also includes the first examples of early OC-type spectra (AAOmega 30 Dor 248 and 280), distinguished by the weakness of their nitrogen spectra and by CIV {lambda}4658 emission. We propose that these stars have relatively unprocessed CNO abundances compared to morphologically normal O-type stars, indicative of an earlier evolutionary phase. From analysis of observations obtained on two consecutive nights, we present radial-velocity estimates for 233 stars, finding one apparent single-lined binary and nine (>3{sigma}) outliers compared to the systemic velocity; the latter objects could be runaway stars or large-amplitude binary systems and further spectroscopy is required to investigate their nature.
- ID:
- ivo://CDS.VizieR/J/ApJS/180/117
- Title:
- MK classifications of spectroscopic binaries
- Short Name:
- J/ApJS/180/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New MK spectral classifications are given for 145 spectroscopic binaries (SBs) with A-F primaries because two-dimensional types are lacking for more than one-third of the A-F SBs with known orbital elements in the current catalog. Compared with the classifications by Morgan, Keenan, and their students, the new classifications give types that are 1.1+/-0.2 subclasses later and 0.7+/-0.1 luminosity classes fainter. Also listed are selected published MK types from Brian Skiff's recent compilation (Cat. <B/mk>).
- ID:
- ivo://CDS.VizieR/J/A+A/655/A4
- Title:
- MONOS II. SB1 Orbital review and analysis
- Short Name:
- J/A+A/655/A4
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Massive stars are a key element to understand the chemical and dynamical evolution of galaxies. Stellar evolution is conditioned by many factors: rotation, mass loss, and interaction with other objects are the most important ones for massive stars. During the first evolutionary stages of stars with initial masses (i.e. M_ZAMS_) in the M_ZAMS_~18-70M_{sum}_ range they are of spectral type O. Given that stars in this mass range spend roughly 90% of their lifetime as O-type stars, establishing the multiplicity frequency and binary properties of O-type stars is crucial for many fields of modern astrophysics. The aim of the MONOS project is to collect information to study Northern Galactic O-type spectroscopic binaries. In this second paper, we tackle the study of the 35 single line spectroscopic binary (SB1) systems identified in the previous paper of the series Maiz Apellaniz et al., (2019, Cat. J/A+A/626/A20) analyze our data, and review the literature on the orbits of the systems. We have measured ~4500 radial velocities for a selection of diagnostic lines for the ~700 spectra of the studied systems in our database, for which we have used two different methods: Gaussian fit for several lines per object and cross-correlation with synthetic spectra computed with the FASTWIND stellar atmospheric code. We have also explored the photometric data delivered by the TESS mission to analyze the light-curve (LC) of the systems extracting 31 of them. We have explored the possible periods with the Lomb-Scargle method and, whenever possible, calculated the orbital solutions using the SBOP&GBART codes. For those systems in which an improved solution was possible we have merged our RVs with those in the literature and calculated a combined solution. As a result of this work, of the 35 SB1 systems identified in MONOS I, we have confirmed 21 systems as SB1 with good orbits, discarded the binary nature of 6 stars (9 Sge, HD 192281, HDE 229232 AB, 68 Cyg, HD 108 and {alpha} Cam), and left 6 stars as inconclusive due to lack of data. The remaining two stars are 15 Mon Aa which has been classified as SB2 and Cyg OB2-22 C for which we find evidence that it is most likely a triple system where the O star is orbiting an eclipsing SB1. We have also recalculated 20 new orbital solutions, including the first spectroscopic orbital solution for V747 Cep. For Cyg OB2-22 C we have obtained new ephemerides but no new orbit.
- ID:
- ivo://CDS.VizieR/J/A+A/626/A20
- Title:
- MONOS. I. Spectral classifications
- Short Name:
- J/A+A/626/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multiplicity in massive stars is a key element to understand the chemical and dynamical evolution of galaxies. Among massive stars, those of O type play a crucial role due to their high masses and short lifetimes. MONOS (Multiplicity Of Northern O-type Spectroscopic systems) is a project designed to collect information and study O-type spectroscopic binaries with {delta}>20{deg}. In this first paper we describe the sample and provide spectral classifications and additional information for objects with previous spectroscopic and/or eclipsing binary orbits. In future papers we will test the validity of previous solutions and calculate new spectroscopic orbits. The spectra in this paper have two sources: the Galactic O-Star Spectroscopic Survey (GOSSS), a project that is obtaining blue-violet R~2500 spectroscopy of thousands of massive stars, and LiLiMaRlin, a library of libraries of high-resolution spectroscopy of massive stars obtained from four different surveys (CAFE-BEANS, OWN, IACOB, and NoMaDS) and additional data from our own observing programs and public archives. We also use lucky images obtained with AstraLux. We present homogeneous spectral classifications for 92 O-type spectroscopic multiple systems and ten optical companions, many of them original.We discuss the visual multiplicity of each system with the support of AstraLux images and additional sources. For eleven O-type objects and for six B-type objects we present their first GOSSS spectral classifications. For two known eclipsing binaries we detect double absorption lines (SB2) or a single moving line (SB1) for the first time, to which we add a third system already reported by us recently. For two previous SB1 systems we detect their SB2 nature for the first time and give their first separate spectral classifications, something we also do for a third object just recently identified as a SB2. We also detect nine new astrometric companions and provide updated information on several others. We emphasize the results for two stars: for {sigma} Ori AaAbB we provide spectral classifications for the three components with a single observation for the first time thanks to a lucky spectroscopy observation obtained close to the Aa,Ab periastron and for {theta}^1^ Ori CaCb we add it to the class of Galactic Of?p stars, raising the number of its members to six. Our sample of O-type spectroscopic binaries contains more triple- or higher-order systems than double systems.
