scholarly journals KIC 7385478: An Eclipsing Binary with a γ Doradus Component

2017 ◽  
Vol 34 ◽  
Author(s):  
Orkun Özdarcan ◽  
Hasan Ali Dal
Keyword(s):  
Light Curve ◽  
Orbital Period ◽  
Spectroscopic Data ◽  
Primary Component ◽  
Secondary Component ◽  
Photometric Analysis ◽  
Eclipsing Binary ◽  
Cool Star ◽  
Star Activity ◽  
Dominant Period

AbstractWe present spectroscopic and photometric analysis of the eclipsing binary KIC 7385478. We find that the system is formed by F1V + K4III–IV components. Combining results from analysis of spectroscopic data and Kepler photometry, we calculate masses and radii of the primary and the secondary components as M1 = 1.71 ± 0.08 M⊙, M2 = 0.37 ± 0.04 M⊙ and R1 = 1.59 ± 0.03 R⊙, R2 = 1.90 ± 0.03 R⊙, respectively. Position of the primary component in HR diagram is in the region of γ Doradus type pulsators and residuals from light curve modelling exhibit additional light variation with a dominant period of ~ 0.5 d. These are clear evidences of the γ Doradus type pulsations on the primary component. We also observe occasional increase in amplitude of the residuals, where the orbital period becomes the most dominant period. These may be attributed to the cool star activity originating from the secondary component.

The Eclipsing Binary WX Eridani

1979 ◽  
Vol 46 ◽  
pp. 385
Author(s):  
M.B.K. Sarma ◽  
K.D. Abhankar
Keyword(s):  
Light Curve ◽  
Spectral Type ◽  
Orbital Period ◽  
Primary Component ◽  
Light Curves ◽  
Absorption Feature ◽  
Primary Star ◽  
Eclipsing Binary ◽  
The Times ◽  
Phase Angles

AbstractThe Algol-type eclipsing binary WX Eridani was observed on 21 nights on the 48-inch telescope of the Japal-Rangapur Observatory during 1973-75 in B and V colours. An improved period of P = 0.82327038 days was obtained from the analysis of the times of five primary minima. An absorption feature between phase angles 50-80, 100-130, 230-260 and 280-310 was present in the light curves. The analysis of the light curves indicated the eclipses to be grazing with primary to be transit and secondary, an occultation. Elements derived from the solution of the light curve using Russel-Merrill method are given. From comparison of the fractional radii with Roche lobes, it is concluded that none of the components have filled their respective lobes but the primary star seems to be evolving. The spectral type of the primary component was estimated to be F3 and is found to be pulsating with two periods equal to one-fifth and one-sixth of the orbital period.

scholarly journals The Wolf-Rayet Eclipsing Binary HD 5980 in the Small Magellanic Cloud

1982 ◽  
Vol 99 ◽  
pp. 317-320
Author(s):  
Jacques Breysacher ◽  
Anthony F. J. Moffat ◽  
Virpi S. Niemelä
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Orbital Period ◽  
Spectroscopic Data ◽  
Magellanic Cloud ◽  
Small Magellanic Cloud ◽  
Eccentric Orbit ◽  
Eclipsing Binary ◽  
Hii Region ◽  
Rayet Star

The Wolf-Rayet star HD 5980, which is probably associated with the bright HII region NGC 346 of the Small Magellanic Cloud, was found to be an eclipsing binary by Hoffmann, Stift and Moffat (1978). Breysacher and Perrier (1980) determined the orbital period, P=19.266±0.003d, of the system whose light curve reveals a strongly eccentric orbit (e=0.47 for i=80°). The behaviour of the light curve outside the eclipses shows that we are dealing with a rather complex binary system. An analysis of the spectroscopic data is presented here.

Updated pulsation period relations of γ Dor-type stars in eclipsing binaries: the case of KIC 2557430

2019 ◽  
Vol 491 (4) ◽  
pp. 5980-5990
Author(s):  
Barış Hoyman ◽  
Ömür Çakırlı ◽  
Orkun Özdarcan
Keyword(s):  
Light Curve ◽  
Physical Properties ◽  
Optical Spectroscopy ◽  
Binary Stars ◽  
Spectroscopic Data ◽  
Primary Component ◽  
Eclipsing Binaries ◽  
Light Variation ◽  
Pulsation Period ◽  
Dominant Period

ABSTRACT We employ optical spectroscopy and Kepler photometry to derive the physical properties and pulsational characteristics of the detached system KIC 2557430. We find that the system is formed by F-type components. Combining results from the analysis of spectroscopic data and Kepler photometry, we calculate masses and radii of the primary and the secondary components as M1 = 1.69 ± 0.03 M⊙, M2 = 1.35 ± 0.02 M⊙ and R1 = 1.88 ± 0.02 R⊙, R2 = 1.23 ± 0.03 R⊙, respectively. Position of the primary component in the HR diagram is in the region of γ Doradus-type pulsators and the residuals from light curve modelling exhibit additional light variation with a dominant period of ∼0.5 d−1. These are clear evidence of the γ Doradus-type pulsations on the primary component. Focusing on the γ Dor primaries, with their currently known numbers in eclipsing binaries to compare against, we probe the role binary stars might play, to understand the nature of γ Dor-type pulsations.

scholarly journals The Subdwarf Eclipsing Binary LB3459 (AA Dor)

1982 ◽  
Vol 69 ◽  
pp. 455-456
Author(s):  
R.W. Hilditch ◽  
Graham Hill ◽  
D. Kilkenny
Keyword(s):  
Light Curve ◽  
Observational Data ◽  
Spectroscopic Data ◽  
Main Sequence ◽  
Primary Component ◽  
Curve Analysis ◽  
Current Status ◽  
Evolutionary Models ◽  
Light Curve Analysis ◽  
Normal Composition

A review was presented of the currently available observational data on this evolved system, namely, uvby photometry (Kilkenny et al. 1978; paper II) radial velocities (Kilkenny et al. 1981; paper III) and a non-LTE atmosphere analysis of the primary component (Kudritski et al. 1981). Kudritski et al. conclude that T(pr) = 40000 ± 2500°K and log g = 5.3 ± 0.2 and from the spectroscopic data and light curve analysis (papers II, III) derive masses and radii for the primary and secondary components of M(pr) ≃ 0.25 M⊙, M(sec) ≃ 0.04 M⊙, R(pr) ≃ 0.16R⊙, R(sec) ≃ 0.09R⊙ respectively. Thus the primary component is a normal sd0 star whilst the secondary component is a most enigmatic object, perhaps a normal composition degenerate dwarf but of too low a mass to be on the main sequence, perhaps an evolved degenerate object but then the radius is too large. The published evolutionary models for this system (Paczynski 1980; Conti et al 1981) do not adequately describe its current status.

scholarly journals Epsilon Aurigae: A Supergiant and a Super Disk

1989 ◽  
Vol 107 ◽  
pp. 336-336
Author(s):  
Sean Carroll ◽  
Edward Guinan ◽  
George McCook ◽  
Robert Donahue
Keyword(s):  
Light Curve ◽  
Orbital Period ◽  
Instability Strip ◽  
Eclipsing Binary ◽  
Characteristic Period ◽  
Photoelectric Observations ◽  
Low Amplitude ◽  
Epsilon Aurigae ◽  
Villanova University

The eclipsing binary Epsilon Aurigae consists of an F0 supergiant and a cool, mysterious eclipsing companion with an orbital period of 27.1 years. The light curve of this system reveals two sources of variability: the eclipses themselves and the intrinsic variation of the supergiant. Multifilter photoelectric observations were made with the 38 cm reflector at the Villanova University Observatory. These data were analyzed along with other sources to reveal the nature of the components of the Epsilon Aurigae system. The system undergoes low-amplitude semi-regular light variations with a characteristic period of 110 days and perhaps a longer period of 500-600 days. The proximity of Epsilon Aur to the Cepheid instability strip on the H-R diagram suggests that the pulsation mechanism for this star may be similar to that of Cepheids.

Detection of Sectoral Modes in the Eclipsing Binary KIC 4851217

2017 ◽  
Vol 14 (S339) ◽  
pp. 295-298
Author(s):  
M. Fedurco ◽  
Š. Parimucha ◽  
P. Gajdoš
Keyword(s):  
Light Curve ◽  
Frequency Analysis ◽  
Secondary Component ◽  
Frequency Range ◽  
Eclipsing Binary ◽  
Quadrupole Mode ◽  
Linear Coupling ◽  
Orbital Frequency ◽  
Short Period ◽  
Low Amplitude

AbstractKIC 4851217 is a short period eclipsing binary (P = 2.47 days) in the field of the Kepler K1 mission. As well as variability caused by the eclipses, low-amplitude pulsations are also present in the data. A frequency analysis of the residual light-curve revealed δ Sct pulsations in the frequency range from 15–21 d−1 with amplitudes up to 3.5 mmag. Strong linear coupling (fi = fp + kforb) to orbital frequency was found, indicating tidally locked modes. From an analysis of 5 selected groups of frequencies we identified a radial mode on the secondary component, 3 dipole modes (l = |m| = 1), one of them present on the secondary component, and a quadrupole mode (l = |m| = 2), also located on the secondary component.

scholarly journals The multiple system Sk-67°18 in the LMC

1995 ◽  
Vol 163 ◽  
pp. 251-253 ◽  
Author(s):  
V. S. Niemela ◽  
W. Seggewiss ◽  
A. F. J. Moffat
Keyword(s):  
Binary System ◽  
Radial Velocity ◽  
Spectral Type ◽  
Orbital Period ◽  
Large Magellanic Cloud ◽  
Primary Component ◽  
Magellanic Cloud ◽  
Bright Star ◽  
High Mass ◽  
Eclipsing Binary

The bright star Sk—67°18 (Brey 5) in the Large Magellanic Cloud (LMC) contains an eclipsing binary system. Our radial velocity study reveals that the orbital period is almost exactly two days. The spectra also show that the star's primary component is not of spectral type WN, but that the star is rather an Of+O type binary where the primary is probably of type O3f*. Furthermore, Sk—67°18 appears to be a high-mass multiple system.

scholarly journals Light curve analysis of the eclipsing binary system V781 Tau

2021 ◽  
Vol 2145 (1) ◽  
pp. 012005
Author(s):  
N Lamlert ◽  
W Maithong
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Orbital Period ◽  
Binary Systems ◽  
Curve Analysis ◽  
Photometric System ◽  
Light Curve Analysis ◽  
Eclipsing Binary ◽  
The Public ◽  
Secondary Star

Abstract V781 Tau is one of W UMa eclipsing binary systems whose orbital period is 0.34 days. The 0.7-meter telescope with CCD photometric system in B and V filters was conducted at the Regional Observatory for the Public, Chachoengsao, Thailand during December 2018, UT. The Wilson-Devinney Technique was used for calculating the physical properties of V781 Tau. The results showed the inclination of their orbital is 66.140°±0.14. The effective temperature of the primary and secondary star is 6,060 and 5,881 K, respectively and the degree of contact is 4.38 %

scholarly journals Light Curve and Orbital Period Analysis of the Eclipsing Binary AT Peg

2011 ◽  
Vol 7 (S282) ◽  
pp. 55-56
Author(s):  
Alexios Liakos ◽  
Panagiotis Niarchos ◽  
Edwin Budding
Keyword(s):  
Light Curve ◽  
Orbital Period ◽  
Time Effect ◽  
Light Curves ◽  
Period Analysis ◽  
Eclipsing Binary ◽  
Secular Changes ◽  
Photometric Observations ◽  
Photometric Elements

AbstractCCD photometric observations of the Algol-type eclipsing binary AT Peg have been obtained. The light curves are analyzed with modern techniques and new geometric and photometric elements are derived. A new orbital period analysis of the system, based on the most reliable timings of minima found in the literature, is presented and apparent period modulations are discussed with respect to the Light-Time effect (LITE) and secular changes in the system. The results of these analyses are compared and interpreted in order to obtain a coherent view of the system's behaviour.

scholarly journals Light curve solutions and out-of-eclipse variability of KIC 10031409, KIC 11228612, KIC 11403216 and KIC 11913071

2017 ◽  
pp. 33-39 ◽  
Author(s):  
D. Kjurkchieva ◽  
T. Atanasova
Keyword(s):  
Light Curve ◽  
Future Study ◽  
Orbital Period ◽  
Secondary Component ◽  
Brown Dwarf ◽  
Detached Binaries ◽  
Rotating Star ◽  
M Dwarf

We carried out light curve solutions of four detached binaries observed by Kepler. As a result, their orbital inclinations, temperatures and relative stellar radii were determined. KIC 10031409 and KIC 11228612 reveal partial eclipses while the components of KIC 11403216 and KIC 11913071 undergo total eclipses. The secondary component of KIC 11403216 is probably a very late M dwarf or brown dwarf. The out-of-eclipse brightness of KIC 10031409, KIC 11228612 and KIC 11913071 vary with the orbital period and might be explained by spots on synchronously-rotating star(s). The out-of-eclipse variability of KIC 11403216 is with a period that is a third of its orbital period and may be due to spot on asynchronous rotating component. The resonance 1:3 needs future study of KIC 11403216.

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