scholarly journals MONOS: Multiplicity Of Northern O-type Spectroscopic systems

2019 ◽  
Vol 626 ◽  
pp. A20 ◽  
Author(s):  
J. Maíz Apellániz ◽  
E. Trigueros Páez ◽  
I. Negueruela ◽  
R. H. Barbá ◽  
S. Simón-Díaz ◽  
...  
Keyword(s):  
Massive Stars ◽  
Dynamical Evolution ◽  
Eclipsing Binaries ◽  
Spectroscopic Binaries ◽  
High Resolution Spectroscopy ◽  
Single Observation ◽  
Multiple Systems ◽  
Additional Information ◽  
Public Archives ◽  
First Time

Context. Multiplicity in massive stars is key to understanding 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. Aims. MONOS (Multiplicity Of Northern O-type Spectroscopic systems) is a project designed to collect information and study O-type spectroscopic binaries with δ >  −20°. 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. Methods. The spectra in this paper have two sources: the Galactic O-Star Spectroscopic Survey (GOSSS), a project that obtains 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 (CAFÉ-BEANS, OWN, IACOB, and NoMaDS) and additional data from our own observing programs and public archives. We have also used lucky images obtained with AstraLux. Results. 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 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 have also done 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 σ 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 θ1 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.

scholarly journals Non-synchronous rotations in massive binary systems

2018 ◽  
Vol 618 ◽  
pp. A174
Author(s):  
C. Putkuri ◽  
R. Gamen ◽  
N. I. Morrell ◽  
S. Simón-Díaz ◽  
R. H. Barbá ◽  
...  
Keyword(s):  
Binary Systems ◽  
Massive Stars ◽  
Spectroscopic Binaries ◽  
Evolutionary Status ◽  
Multiple Systems ◽  
Orbital Parameters ◽  
Link Type ◽  
Tidal Forces ◽  
Relative Separation ◽  
Massive Binary Systems

Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as double-lined spectroscopic binaries and among these, the OWN Survey has detected a non-negligible number whose components show very different spectral line broadening (i.e., projected rotational velocities). This fact raises a discussion about the contributing processes, such as angular-momentum transfer and tidal forces. Aims. We seek to constrain the physical and evolutionary status of one of such systems, the O+O binary HD 93343. Methods. We analyzed a series of high-resolution multiepoch optical spectra to determine the orbital parameters, projected rotational velocities, and evolutionary status of the system. Results. HD 93343 is a binary system comprised of two O7.5 Vz stars that each have minimum masses of approximately 22 M⊙ in a wide and eccentric orbit (e = 0.398±0.004; P = 50.432±0.001 d). Both stars have very similar stellar parameters, and hence ages. As expected from the qualitative appearance of the combined spectrum of the system, however, these stars have very different projected rotational velocities (~65 and ~325 km s−1, respectively). Conclusions. The orbits and stellar parameters obtained for both components seem to indicate that their youth and relative separation is enough to discard the effects of mass transfer and tidal friction. Thus, non-synchronization should be intrinsic to their formation.

scholarly journals Formation of massive binaries

2003 ◽  
Vol 212 ◽  
pp. 80-90 ◽  
Author(s):  
Hans Zinnecker
Keyword(s):  
Stellar Evolution ◽  
Massive Stars ◽  
Star Clusters ◽  
Young Star ◽  
Spectroscopic Binaries ◽  
Stellar Clusters ◽  
Multiple Systems ◽  
Short Period ◽  
Young Star Clusters ◽  
Runaway Stars

The formation of massive stars is one of the major unsolved problems in stellar astrophysics. However, only few if any of these are found as single stars, on average massive stars have more than one companion. Many of them are born in dense stellar clusters and several clusters have an excess of massive short-period spectroscopic binaries, with severe implication for binary-related stellar evolution including mergers, and also for the origin of massive runaway stars. The multiplicity of massive stars seems to increase with increasing primary mass and with increasing density of young star clusters. These observations suggest that massive binary and multiple systems originate mainly from dynamical gravitational interactions and accretion-induced protostellar collisions in dense clusters. If true, the binary properties of massive stars in less dense OB associations should be less extreme. This prediction should be tested by future observations. The paper reviews both the latest observations and theoretical ideas related to the origin of massive binaries. It concludes with a speculation on how the binary properties might change with metallicity (e.g., LMC/SMC).

scholarly journals Orbital and physical parameters of eclipsing binaries from the All-Sky Automated Survey catalogue

2019 ◽  
Vol 622 ◽  
pp. A114 ◽  
Author(s):  
K. G. Hełminiak ◽  
A. Tokovinin ◽  
E. Niemczura ◽  
R. Pawłaszek ◽  
K. Yanagisawa ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Main Sequence ◽  
Eclipsing Binaries ◽  
Spectroscopic Binaries ◽  
Physical Parameters ◽  
Centre Of Mass ◽  
Velocity Measurements ◽  
Spectroscopic Binary ◽  
Quadruple System ◽  
First Time

Aims. We present results of the combined photometric and spectroscopic analysis of three detached eclipsing binaries, the secondary components of which are not visible or are very hard to identify in the optical spectra – ASAS J052743–0359.7, ASAS J065134–2211.5, and ASAS J073507–0905.7. The first one is the known visual binary ADS 4022, and we found that it is a quadruple system composed of two spectroscopic binaries, one of which shows eclipses. None of the systems have previously been recognized as a spectroscopic binary. Methods. We used the following telescopes/spectrographs to collect a number of high-resolution optical and IR spectra: Subaru/IRCS, CTIO-1.5 m/CHIRON, Euler/CORALIE, MPG-2.2 m/FEROS, OAO-188/HIDES, and TNG/HARPS-N. We used these data to calculate radial velocities (RVs) and later combined them with MITSuME and ASAS photometry. The Subaru/IRCS IR spectra were crucial for secure identification of the lines of the cooler components. Radial velocity measurements were made with the TODCOR technique, and RV curves were modelled with our own procedure V2FIT. Light-curve modelling was performed with JKTEBOP and PHOEBE codes. Temperatures and metallicities of two systems were estimated from spectra. For the ADS 4022 system we also used the archival WDS data and new SOAR observations in order to derive the orbit of the visual pair for the first time. Ages were estimated by comparing our results with PARSEC isochrones. Results. The eclipsing pair ASAS J052743–0359.7 A (P = 5.27 d) is composed of a 1.03(6) M⊙, 1.03(2) R⊙ primary and a 0.60(2) M⊙, 0.59(2) R⊙ secondary. The components of the P = 21.57 d non-eclipsing pair B likely have masses in between the two eclipsing components, and both pairs are on a ∼188 yr orbit around their common centre of mass. The system ASAS J065134-2211.5 (P = 8.22 d) consists of a 0.956(12) M⊙, 0.997(4) R⊙ primary and a 0.674(5) M⊙, 0.690(7) R⊙ secondary. Finally, ASAS J073507-0905.7 (P = 1.45 d), which consists of a 1.452(34) M⊙, 1.635(12) R⊙ primary and a 0.808(13) M⊙, 0.819(11) R⊙ secondary, is likely a pre-main sequence system. In all cases secondary eclipses are total.

scholarly journals The effect of stellar multiplicity on protoplanetary discs: a near-infrared survey of the Lupus star-forming region

2020 ◽  
Vol 501 (2) ◽  
pp. 2305-2315
Author(s):  
Alice Zurlo ◽  
Lucas A Cieza ◽  
Megan Ansdell ◽  
Valentin Christiaens ◽  
Sebastián Pérez ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Molecular Cloud ◽  
Near Infrared ◽  
Main Sequence Stars ◽  
Multiple Systems ◽  
Star Forming ◽  
Very Large Telescope ◽  
Pms Stars ◽  
First Time ◽  
Infrared Survey

ABSTRACT We present results from a near-infrared (NIR) adaptive optics (AO) survey of pre-main-sequence stars in the Lupus molecular cloud with NACO at the Very Large Telescope (VLT) to identify (sub)stellar companions down to ∼20-au separation and investigate the effects of multiplicity on circumstellar disc properties. We observe for the first time in the NIR with AO a total of 47 targets and complement our observations with archival data for another 58 objects previously observed with the same instrument. All 105 targets have millimetre Atacama Large Millimetre/sub-millimetre Array (ALMA) data available, which provide constraints on disc masses and sizes. We identify a total of 13 multiple systems, including 11 doubles and 2 triples. In agreement with previous studies, we find that the most massive (Mdust > 50 M⊕) and largest (Rdust > 70 au) discs are only seen around stars lacking visual companions (with separations of 20–4800 au) and that primaries tend to host more massive discs than secondaries. However, as recently shown in a very similar study of >200 PMS stars in the Ophiuchus molecular cloud, the distributions of disc masses and sizes are similar for single and multiple systems for Mdust < 50 M⊕ and radii Rdust < 70 au. Such discs correspond to ∼80–90 per cent of the sample. This result can be seen in the combined sample of Lupus and Ophiuchus objects, which now includes more than 300 targets with ALMA imaging and NIR AO data, and implies that stellar companions with separations >20 au mostly affect discs in the upper 10${{\ \rm per\ cent}}$ of the disc mass and size distributions.

A review of Sharp's types of Aleochara from Latin America (Coleoptera: Staphylinidae)

1989 ◽  
Vol 20 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Jan Klimaszewski
Keyword(s):  
Latin America ◽  
South America ◽  
North American ◽  
Additional Information ◽  
First Time

AbstractA review of David Sharp's types of Aleochara from Mexico, and Central and South America is presented. Nineteen species are treated here, one of which is described as new (A. felixiana), seven are redescribed [A. angusticeps Sharp, A. funestior Sharp, A. mexicana Sharp, A. oxypodia Sharp, A. simulatrix Sharp, A. gracilis (Sharp), and A. duplicata (Sharp)] and one [A. miradoris Sharp] is put in synonymy under A. mexicana Sharp. The remaining ten species were treated in my 1984-revision of North American Aleochara but are here included in a checklist with references to description, redescription, and illustrations. Some additional information is provided for previously synonymized A. torquata Sharp (= A. sallaei Sharp), and for A. quadrata Sharp. Illustrations of genitalic structures of both sexes are provided for the first time for the seven redescribed species. Lectotypes are designated for A. angusticeps, A. duplicata, A. funestior, A. mexicana, and A. oxypodia.

scholarly journals Interferometric Investigations of Eclipsing Binaries as a Key to an Improved Distance Scale

2006 ◽  
Vol 2 (S240) ◽  
pp. 496-498
Author(s):  
K. Shabun ◽  
A. Richichi ◽  
U. Munari ◽  
A. Siviero ◽  
B. Pacsysnki
Keyword(s):  
Spectral Type ◽  
Effective Temperature ◽  
Binary Systems ◽  
Angular Separation ◽  
Eclipsing Binaries ◽  
Multiple Systems ◽  
Long Baseline ◽  
Global Calibration ◽  
Empirical Calibration ◽  
Full Solution

AbstractBinary and multiple systems constitute one of the main tools for obtaining fundamental stellar parameters, such as masses, radii, effective temperatures and distances. One especially fortunate, and at the same time rare, occurrence is that of double-lined eclipsing binaries with well-detached components. In this special case, it is possible to obtain a full solution of all orbital and stellar parameters, with the exception of the effective temperature of one star, which is normally estimated from spectral type or derived from atmospheric analysis of the spectrum. Long-baseline interferometry at facilities such as the ESO VLTI is beginning to have the capability to measure directly the angular separation and the angular diameter of some selected eclipsing binary systems, and we have proposed such observations with the AMBER instrument. In particular, we aim at deriving directly the effective temperature of at least one of the components in the proposed system, thereby avoiding any assumptions in the global solution through the Wilson–Devinney method. We will also obtain an independent check of the results of this latter method for the distance to the system. This represents the first step towards a global calibration of eclipsing binaries as distance indicators. Our results will also contribute to the effective temperature scale for hot stars. The extension of this approach to a wider sample of eclipsing binaries could provide an independent method to assess the distance to the LMC. The observations will extend accurate empirical calibration to spectral type O9 – B0.

scholarly journals What do women know about breast density? A public screening program perspective

2020 ◽  
Author(s):  
Monique Robertson ◽  
Ellie C Darcey ◽  
Evenda K Dench ◽  
Louise Keogh ◽  
Kirsty McLean ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Density ◽  
Screening Program ◽  
Mammographic Screening ◽  
Descriptive Data ◽  
Additional Information ◽  
Dense Breasts ◽  
Increased Risk ◽  
Main Message ◽  
First Time

AbstractBackgroundThis study assesses knowledge of breast density, one of breast cancer’s strongest risk factors, in women attending a public mammographic screening program in Western Australia that routinely notifies women if they have dense breasts.MethodsSurvey data was collected from women who were notified they have dense breasts and women who had not (controls). Descriptive data analysis was used to summarize responses.ResultsOf the 6183 women surveyed, over 85% of notified women knew that breast density makes it difficult to see cancer on a mammogram (53.9% in controls). A quarter of notified women knew that having dense breasts puts women at increased risk for breast cancer (13.2% in controls). Overall, 50.1% of notified women indicated that they thought the amount of information provided was “just right” and 24.9% thought it was “too little”, particularly women notified for the first time (32.1%).ConclusionThe main message of reduced sensitivity of mammography in women with dense breasts provided by the screening program appears to be getting though. However, women are largely unaware that increased breast density is associated with increased risk. Women notified of having dense breasts for the first time could potentially benefit from additional information.

scholarly journals The UVMag space project: UV and visible spectropolarimetry of massive stars

2014 ◽  
Vol 9 (S307) ◽  
pp. 389-390
Author(s):  
Coralie Neiner ◽  
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Massive Stars ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Medium Size ◽  
Space Project ◽  
First Time ◽  
The Magnetic Field ◽  
Circumstellar Environment

AbstractUVMag is a medium-size space telescope equipped with a high-resolution spectropolarimetrer working in the UV and visible domains. It will be proposed to ESA for a future M mission. It will allow scientists to study all types of stars as well as e.g. exoplanets and the interstellar medium. It will be particularly useful for massive stars, since their spectral energy distribution peaks in the UV. UVMag will allow us to study massive stars and their circumstellar environment (in particular the stellar wind) spectroscopically in great details. Moreover, with UVMag's polarimetric capabilities we will be able, for the first time, to measure the magnetic field of massive stars simultaneously at the stellar surface and in the wind lines, i.e. to completely map their magnetosphere.

The two eccentric eclipsing binaries in multiple systems: V539 Arae and V335 Serpentis

New Astronomy ◽  
2021 ◽  
pp. 101708
Author(s):  
M. Wolf ◽  
M. Zejda ◽  
M. Mašek ◽  
H. Kučáková ◽  
M. Souza de Joode ◽  
...  
Keyword(s):  
Eclipsing Binaries ◽  
Multiple Systems
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