scholarly journals Study of Eclipsing Binary and Multiple Systems in OB Associations IV: Cas OB6 Member DN Cas

2016 ◽  
Vol 33 ◽  
Author(s):  
V. Bakış ◽  
H. Bakış ◽  
S. Bilir ◽  
Z. Eker
Keyword(s):  
Orbital Period ◽  
Early Type ◽  
Eccentric Orbit ◽  
Period Analysis ◽  
Multiple Systems ◽  
Spectroscopic Binary ◽  
Short Period ◽  
Synchronous Rotation ◽  
The Masses ◽  
Absolute Parameters

AbstractAn early-type, massive, short-period ($P_{\text{orb}}=2^d.310951$) eclipsing spectroscopic binary DN Cas has been re-visited with new spectral and photometric data. The masses and radii of the components have been obtained as $M_1=19.04\pm 0.07\,\text{M}_\odot$, $M_2=13.73\pm 0.05\,\text{M}_\odot$ and $R_1=7.22\pm 0.06\,\text{R}_\odot$, $R_2=5.79\pm 0.06\,\text{R}_\odot$, respectively. Both components present synchronous rotation ($V_{\text{rot}1}=160\,\text{km } \text{s}^{-1}$, $V_{\text{rot}2}=130\ \text{km} \,\text{s}^{-1}$) with their orbit. Orbital period analysis yielded a physically bound additional component in the system with a minimum mass of $M_3=0.88\,\text{M}_\odot$ orbiting in an eccentric orbit (e = 0.37 ± 0.2) with an orbital period of P12 = 42 ± 9 yr. High precision absolute parameters of the system allowed us to derive a distance to DN Cas as 1.7 ± 0.2 kpc which locates the system within the borders of the Cas OB6 association (d = 1.8 kpc). The space velocities and the age of DN Cas are in agreement with those of Cas OB6. The age of DN Cas (τ = 3–5 Myr) is found to be 1–2 Myr older than the embedded clusters (IC 1795, IC 1805, and IC 1848) in the Cas OB6 association, which implies a sequential star formation in the association.

scholarly journals Line-profile variable ɛ Per: spectroscopic binary and (?) mild Be star

1994 ◽  
Vol 162 ◽  
pp. 325-326
Author(s):  
A.E. Tarasov ◽  
V.V. Kostunin ◽  
P. Harmanec ◽  
J. Horn ◽  
P. Koubský ◽  
...  
Keyword(s):  
Line Profile ◽  
Early Type ◽  
Eccentric Orbit ◽  
Composite Spectrum ◽  
Binary Nature ◽  
Spectroscopic Binary ◽  
Be Star

ɛ Per (45 Per, HR 1220, HD 24760, ADS 2888A) is a star which was used for years as a spectrophotometric and MKK classification standard. Nowadays it is known as an archetype of early-type line-profile variables (LPV). The variations are so pronounced that they were misinterpreted for a composite spectrum (B0.5+A2) and the star was even reported to be a double-lined spectroscopic binary (Petrie 1958). Since 1983, the characteristics of line-profile variability in the spectrum of ɛ Per have been intensively studied (Bolton 1983, Smith 1985, Gies & Kullavanijaya 1988). The recent investigations of RV variations of ɛ Per led to the conclusion that ɛ Per is a spectroscopic binary with a period of about 14.05 days and a rather eccentric orbit (Harmanec & Tarasov 1990). The issue of the binary nature (with a very eccentric orbit) is of utmost importance since it could be causally related to the extremely large observed line-profile variations (e.g., Polfliet & Smeyers 1990, Tassoul & Tassoul 1992).

scholarly journals Photometry of the δ Scuti Star DG Leo: Preliminary Results

2004 ◽  
Vol 191 ◽  
pp. 73-74 ◽  
Author(s):  
P. Lampens ◽  
R. Garrido ◽  
L. Parrao ◽  
J.H. Peña ◽  
T. Arentoft ◽  
...  
Keyword(s):  
Orbital Period ◽  
Noise Level ◽  
Amplitude Spectrum ◽  
Slow Variation ◽  
Photoelectric Photometry ◽  
Period Analysis ◽  
Preliminary Results ◽  
Spectroscopic Binary ◽  
Scuti Star ◽  
Triple Star

AbstractNew uvby photoelectric photometry has been acquired for the triple star DG Leo at two different observatories equipped with analogous instrumentation. A preliminary period analysis indicates the presence of at least 3 close δ Scuti frequencies (10-12 c/d, 3-6 mmag) and a slow variation. This slow variation fits quite well with half the orbital period of the spectroscopic binary; the noise level in the amplitude spectrum is only 3–4 mmag (after prewhitening).

scholarly journals The Cluster AgeS Experiment (CASE) – VIII. Age and distance of the Globular Cluster 47 Tuc from the analysis of two detached eclipsing binaries

2020 ◽  
Vol 492 (3) ◽  
pp. 4254-4267 ◽  
Author(s):  
I B Thompson ◽  
A Udalski ◽  
A Dotter ◽  
M Rozyczka ◽  
A Schwarzenberg-Czerny ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Orbital Period ◽  
Surface Brightness ◽  
Eclipsing Binaries ◽  
Helium Abundance ◽  
Eccentric Orbit ◽  
Photometric And Spectroscopic Observations ◽  
Magnitude Diagram ◽  
The Masses ◽  
Gaia Dr2

ABSTRACT We use photometric and spectroscopic observations of the eclipsing binary E32 in the globular cluster 47 Tuc to derive the masses, radii, and luminosities of the component stars. The system has an orbital period of 40.9 d, a markedly eccentric orbit with e = 0.24, and is shown to be a member of or a recent escaper from the cluster. We obtain $M_{\rm p} = 0.862\pm 0.005 \, \mathrm{M}_\odot$, $R_{\rm p} = 1.183\pm 0.003 \, \mathrm{R}_\odot$, $L_{\rm p} = 1.65\pm 0.05 \, \mathrm{L}_\odot$ for the primary and $M_{\rm s} = 0.827\pm 0.005 \, \mathrm{M}_\odot$, $R_{\rm s} = 1.004\pm 0.004 \, \mathrm{R}_\odot$, $L_{\rm s} = 1.14\pm 0.04\, \mathrm{L}_\odot$ for the secondary. Based on these data and on an earlier analysis of the binary V69 in 47 Tuc, we measure the distance to the cluster from the distance moduli of the component stars, and, independently, from a colour – surface brightness calibration. We obtain 4.55 ± 0.03 and 4.50 ± 0.07 kpc, respectively – values compatible within 1$\, \sigma$ with recent estimates based on Gaia DR2 parallaxes. By comparing the M–R diagram of the two binaries and the colour–magnitude diagram of 47 Tuc to Dartmouth model isochrones we estimate the age of the cluster to be 12.0 ± 0.5 Gyr, and the helium abundance of the cluster to be Y ≈ 0.25.

scholarly journals GG Carinae: discovery of orbital-phase-dependent 1.583-day periodicities in the B[e] supergiant binary

2021 ◽  
Vol 503 (4) ◽  
pp. 4802-4814
Author(s):  
Augustus Porter ◽  
Katherine Blundell ◽  
Philipp Podsiadlowski ◽  
Steven Lee
Keyword(s):  
Orbital Period ◽  
Primary Component ◽  
Emission Lines ◽  
Optical Monitoring ◽  
Eccentric Orbit ◽  
Tidal Forces ◽  
Short Period ◽  
Period Variations ◽  
Orbital Phase ◽  
Monitoring Camera

ABSTRACT GG Carinae (GG Car) is a binary whose primary component is a B[e] supergiant. Using photometric data from the Transiting Exoplanet Survey Satellite (TESS), All Sky Automated Survey (ASAS), Optical Monitoring Camera (OMC), and All Sky Automated Survey for Supernovae (ASAS-SN), and spectroscopic data from the Global Jet Watch to study visible He i, Fe ii, and Si ii emission lines, we investigate the short-period variations that are exhibited in GG Car. We find a hitherto neglected periodicity of 1.583156 ± 0.0002 d that is present in both its photometry and the radial velocities of its emission lines, alongside variability at the well-established ∼31-d orbital period. We find that the amplitudes of the shorter period variations in both photometry and some of the emission lines are modulated by the orbital phase of the binary, such that the short-period variations have largest amplitudes when the binary is at periastron. There are no significant changes in the phases of the short-period variations over the orbital period. We investigate potential causes of the 1.583-d variability, and find that the observed period agrees well with the expected period of the l = 2 f-mode of the primary given its mass and radius. We propose that the primary is periodically pulled out of hydrostatic equilibrium by the quadrupolar tidal forces when the components are near periastron in the binary’s eccentric orbit (e = 0.5) and the primary almost fills its Roche lobe. This causes an oscillation at the l = 2 f-mode frequency that is damped as the distance between the components increases.

In real clinical practice osteoporosis drugs are taken for a very short period: analysis of persistence in the campania region

2013 ◽  
Author(s):  
Giovanni Iolascon ◽  
Annarita Capaldo ◽  
Valentina Orlando ◽  
Enrica Menditto ◽  
Francesca Gimigliano
Keyword(s):  
Clinical Practice ◽  
Campania Region ◽  
Period Analysis ◽  
Short Period ◽  
Real Clinical Practice

Erratum: “Virgo Redux: The Masses and Stellar Content of Nuclei in Early-type Galaxies from Multiband Photometry and Spectroscopy” (2017, ApJ, 849, 55)

2018 ◽  
Vol 869 (1) ◽  
pp. 85
Author(s):  
Chelsea Spengler ◽  
Patrick Côté ◽  
Joel Roediger ◽  
Laura Ferrarese ◽  
Rubén Sánchez-Janssen ◽  
...  
Keyword(s):  
Early Type ◽  
Stellar Content ◽  
The Masses

scholarly journals The Census of Exoplanets in Visual Binaries: Population Trends from a Volume-Limited Gaia DR2 and Literature Search

2021 ◽  
Vol 8 ◽  
Author(s):  
Clémence Fontanive ◽  
Daniella Bardalez Gagliuffi
Keyword(s):  
Planetary Systems ◽  
Multiple Star ◽  
Multiple Systems ◽  
Binary Separation ◽  
Extensive Search ◽  
Short Period ◽  
Massive Component ◽  
Low Mass ◽  
Cool Gas ◽  
Gaia Dr2

We present results from an extensive search in the literature and Gaia DR2 for visual co-moving binary companions to stars hosting exoplanets and brown dwarfs within 200 pc. We found 218 planet hosts out of the 938 in our sample to be part of multiple-star systems, with 10 newly discovered binaries and 2 new tertiary stellar components. This represents an overall raw multiplicity rate of 23.2 ± 1.6 % for hosts to exoplanets across all spectral types, with multi-planet systems found to have a lower stellar duplicity frequency at the 2.2-σ level. We found that more massive hosts are more often in binary configurations, and that planet-bearing stars in multiple systems are predominantly observed to be the most massive component of stellar binaries. Investigations of the multiplicity of planetary systems as a function of planet mass and separation revealed that giant planets with masses above 0.1 MJup are more frequently seen in stellar binaries than small sub-Jovian planets with a 3.6-σ difference, a trend enhanced for the most massive (>7 MJup) short-period (<0.5 AU) planets and brown dwarf companions. Binarity was however found to have no significant effect on the demographics of low- mass planets (<0.1 MJup) or warm and cool gas giants (>0.5 AU). While stellar companion mass appears to have no impact on planet properties, binary separation seems to be an important factor in the resulting structure of planetary systems. Stellar companions on separations <1000 AU can play a role in the formation or evolution of massive, close-in planets, while planets in wider binaries show similar properties to planets orbiting single stars. Finally, our analyses indicate that numerous stellar companions on separations smaller than 1–3 arcsec likely remain undiscovered to this date. Continuous efforts to complete our knowledge of stellar multiplicity on separations of tens to hundreds of AU are essential to confirm the reported trends and further our understanding of the roles played by multiplicity on exoplanets.

Radial Velocity Variations in Cool Supergiants

1984 ◽  
Vol 88 ◽  
pp. 283-288
Author(s):  
Hugh C. Harris
Keyword(s):  
Radial Velocity ◽  
Main Sequence ◽  
Short Period ◽  
Cool Stars ◽  
Synchronous Rotation ◽  
Red Supergiants ◽  
Velocity Variations ◽  
Orbital Periods ◽  
Low Amplitude ◽  
Good Agreement

AbstractA survey of F, G, and W supergiants has been carried out with the DAO radial velocity spectrometer, an efficient instrument for detecting low-amplitude velocity variations in cool stars. Observations of 78 stars over five seasons show generally good agreement with OORAVEL results for spectroscopie binaries. The majority of supergiants show low-amplitude variability, with amplitudes typically 1 to 2 km s−1. The width of the cross-correlation profile has been measured for 58 supergiants. It reveals 14 stars with unusually broad lines, indicative of rotation velocities of 15 to 35 km s−1. Several have short-period binary companions and may be in synchronous rotation. The other broad-lined stars are apparently single or with long orbital periods; they may be making their first transition from the main sequence to become red supergiants.

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