scholarly journals BVRcIc Observations and Analysis of the Near-Contact Solar Type Eclipsing Binary, V530 Andromedae

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Ronald G. Samec ◽  
Daniel Flaaten ◽  
James Kring ◽  
Danny R. Faulkner

We present the first precision UBVRcIc light curves, an initial period study, and a simultaneous light curve solution for the near-contact solar type eclipsing binary V530 And. Our observations were taken with the 0.81 m Lowell reflector on 27 and 29 September, 2011, with time being granted from the National Undergraduate Research Observatory (NURO). Our Wilson Devinney Program solution yields a semidetached, V1010 Oph configuration: the more massive component is filling its Roche lobe. The system is apparently approaching contact for the first time. It is not a classic Algol.

2012 ◽  
Vol 2012 ◽  
pp. 1-11
Author(s):  
Ronald G. Samec ◽  
Adam Jaso ◽  
Jesse White ◽  
Danny R. Faulkner ◽  
Nicholas Blum ◽  
...  

TYC 3034-0299-1 (CVn) is a magnetically active, contact binary, ROTSE variable. UBVRcIc light curves are presented along with a period study and a simultaneous UBVRI light curve solution. Our light curves show eclipse amplitudes of 0.72 and 0.62 mags (V) in the primary and secondary eclipses. Modeled results include a dark spot region, found at longitude 51°, a 24% Roche lobe fill-out, and a mass ratio of 0.48. A total eclipse is found to occur in the secondary eclipse making TYC 3034-0299-1 a W-type (less massive star is hotter) W UMa variable.


2018 ◽  
Vol 14 (S346) ◽  
pp. 288-293
Author(s):  
Ronald G. Samec ◽  
Heather Chamberlain ◽  
Daniel Caton ◽  
Russell Robb ◽  
Danny R. Faulkner

AbstractComplete BVRCIC light curves of V1187 Her were obtained in May 2017 at the Dark Sky Observatory in North Carolina with the 0.81-m reflector of Appalachian State University. Earlier, spectra were taken at the Dominion Astrophysical Observatory with the 1.8-m telescope. The spectral type was found to be F8±1 V (6250 K), so the binary is of solar-type. V1187 Her was previously identified as a low amplitude (V < 0.2 mag), short period, overcontact eclipsing binary (EW) with a period of 0.310726 d. Strikingly, despite its low amplitude, the early light curves show total eclipses (eclipse duration ≍31.5 minutes), which is a characteristic of an extreme mass ratio binary. A period study covering 11 years reveals a continuous period decrease dP/dt=–4.7×10–9 d yr–1. The multi-band Wilson-Devinney light curve solution gives a fill-out of 79% and a mass ratio of only 0.0440±0.0001. There is a cool spot region on the secondary component, which is 400 K hotter than the primary. The inclination is only 66.85±0.05 despite the system’s total eclipses.


1979 ◽  
Vol 46 ◽  
pp. 385
Author(s):  
M.B.K. Sarma ◽  
K.D. Abhankar

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.


2020 ◽  
Vol 29 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Fatemeh Davoudi ◽  
Atila Poro ◽  
Fahri Alicavus ◽  
Afshin Halavati ◽  
Saeed Doostmohammadi ◽  
...  

AbstractNew observations of the eclipsing binary system V1848 Ori were carried out using the V filter resulting in a determination of new times of minima and new ephemeris were obtained. We presented the first complete analysis of the system’s orbital period behavior and analysis of O-C diagram done by the GA and MCMC approaches in OCFit code. The O-C diagram demonstrates a sinusoidal trend in the data; this trend suggests a cyclic change caused by the LITE effect with a period of 10.57 years and an amplitude of 7.182 minutes. It appears that there is a third body with mass function of f (m3) = 0.0058 M⊙ in this binary system. The light curves were analyzed using the Wilson-Devinney code to determine some geometrical and physical parameters of the system. These results show that V1848 Ori is a contact W UMa binary system with the mass ratio of q = 0.76 and a weak fillout factor of 5.8%. The O’Connell effect was not seen in the light curve and there is no need to add spot.


1989 ◽  
Vol 107 ◽  
pp. 355-355
Author(s):  
Burt Nelson ◽  
Walter D. Davis

Observations of U Cephei made by C. M. Huffer, et al, in 1950-51 and in 1959, are presented here to contrast with other observations made by Huffer and others.In many cases, to see a light-curve of an eclipsing binary is to see all light-curves for that particular system. This is certainly not true of U Cephei which, because of its rapid variations, has held the attention of so many for so long.The 1950-51 yellow and blue observations were made at Washburn Observatory, Madison. The data have been transcribed from Huffer’s note books to a floppy disk and are available.


2011 ◽  
Vol 7 (S282) ◽  
pp. 199-200
Author(s):  
Krisztián Vida ◽  
Katalin Oláh ◽  
Zsolt Kővári

AbstractV405 And is an ultrafast-rotating (Prot ≈ 0.46 days) eclipsing binary. The system consists of a primary star with radiative core and convective envelope, and a fully convective secondary. Theories have shown that stellar structure can depend on magnetic activity, i.e., magnetically active M-dwarfs should have larger radii. Earlier light curve modelling of V405 And indeed showed this behaviour: we found that the radius of the primary is significantly larger than the theoretically predicted value for inactive main sequence stars (the discrepancy is the largest of all known objects), while the secondary fits well to the mass-radius relation. By modelling our recently obtained light curves, which show significant changes of the spotted surface of the primary, we can find further proof for this phenomenon.


2014 ◽  
Vol 572 ◽  
pp. A71 ◽  
Author(s):  
P. Zasche ◽  
M. Wolf ◽  
J. Vraštil ◽  
J. Liška ◽  
M. Skarka ◽  
...  

2020 ◽  
Vol 56 (2) ◽  
pp. 225-234
Author(s):  
M. Martignoni ◽  
C. Barani ◽  
F. Acerbi ◽  
R. Michel

The multicolour CCD light curves of the eclipsing binary systems CRTS J213033.6+213159 and 1SWASP J212454.61+203030.8 are presented for the first time, the observations are analyzed using the latest version of the WilsonDevinney code. Both the systems are found to be W UMa contact binaries belonging two different subtypes. All the light curves show the inverse O'Connell effect. By using our 2 times of minimum light for both the systems and the 187 and 105 ToMs extract from the SWASP observations, respectively for CRTS J213033.6+213159 and for 1SWASP J212454.61+203030.8, the orbital periods are here revised. The spectral type K of the systems and their short orbital periods (< 0.3 days), suggests that they are near the shortest period limit. The absolute dimensions are estimated and, from statistical diagrams, it is found that both components of the systems follow the general pattern of the relative subtype of W Ursae Majoris systems.


2016 ◽  
Vol 1 (2) ◽  
pp. 321-334 ◽  
Author(s):  
N.S. Awadalla ◽  
M.A. Hanna ◽  
M.N. Ismail ◽  
I.A. Hassan ◽  
M.A. Elkhamisy

AbstractWe analyzed the first set of complete CCD light curves of the W UMa type eclipsing binary IK Boo in the BVRI bands by using the PHOEBE code and deduced its first photometric parameters with, mass ratio q = 0.648 and orbital inclination i = 63o. We have applied a spotted model due to the light curves asymmetry. The system shows a distinct O’Connell effect. The best solution fit to the light curves suggested the influence of star spot(s) on both components. Such presence of star spot(s) is common among the RS CVn and W UMa chromospheric active late type stars.We also present an analysis of mid–eclipse time measurements of IK Boo. The analysis indicates a period decrease rate dP/dt = −1.68 × 10−7d/yr, which can be interpreted in terms of mass transfer of rate 3.1 × 10−7M⊙/yr, from the more massive to the less massive component.


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