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Yang, Yisi; Liu, Qingyao

doi:10.1023/a:1026545905650

Cited by 7 publications

(7 citation statements)

References 8 publications

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“…The period decrease had been well discussed (Aslan & Herczeg, 1984;Wolf & Diethelm, 1992;Sezer, 1993;Morris & Naftilan, 2000;Yang & Liu, 2000). We tried to fit the O-C curve with downward parabola…”

Section: O-c Diagram Analysesmentioning

confidence: 96%

“…In our O-C analysis, we adopt different weight for different-precision data, i.e. a weight of 5 for CCD (ccd) and photoelectric (pe) data and a low weight of 1 for visual (vis) and photographic (pg) data, as same as that of Yang & Liu (2000). The combination of the change of continuum decrease and cyclic variation gives a good fit to the O-C curve.…”

Section: O-c Diagram Analysesmentioning

confidence: 99%

“…Ṗ = −7.8 × 10 −10 days • cycle −1 ). 17 years ago, Morris & Naftilan (2000) pointed out that the period had decreased 0.795 ± 0.040s around JD 2,445,000 in 1982, while Yang & Liu (2000) found that the period was decreasing at a rate of Ṗ = −8.8 × 10 −10 days • cycle −1 from 1962 to 1998 year, using 111 data including 62 pe data in their analysis. By now, more high-precision eclipse times have been obtained, which are very useful for more precise period investigation.…”

Section: Introductionmentioning

confidence: 99%

“…Strohmeier (1960) first recognized the variability of V1073 Cyg, then the photographic (pg) light curve was published in 1962 (Strohmeier 1962). Thus far, more photometric and spectrographic researches have been carried out for V1073 Cyg (such as Sezer 1993;Morris & Naftilan 2000;Yang & Liu 2000;Ekmekc ¸i et al 2012), and absolute parameters have been derived. Here is a brief introduction.…”

Section: Introductionmentioning

confidence: 99%

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Multi-color light curves and orbital period research of eclipsing binary V1073 Cyg

Tian

Zhu

Qian

et al. 2018

Res. Astron. Astrophys.

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New Multi-color B V R c I c photometric observation are presented for W UMa type eclipsing binary V1073 Cyg. The multi-color light curves analysis with the Wilson-Devinney(W-D) procedure acquired the absolute parameters of this system, showing thatV1073Cyg is a shallow contact binary system with fill-out factor f = 0.124(±0.011). We collected all available times of light minima spanning 119 years including CCD data to construct the O-C curve and made detailed O-C analysis. The O-C diagram shows that the period change is complex. There exist a long-term continuous decrease and a cyclic variation. The period is decreasing at a rate ofṖ = −1.04(±0.18) × 10 −10 days · cycle −1 , and with the period decrease, V1073 Cyg will evolve to deep contact stage. The cyclic variation with a period of P 3 = 82.7(±3.6)years and an amplitude of A = 0.028(±0.002)day may be explained by the magnetic activity of one or both components or the light travel time effect (LTTE) caused by a distant third companion with M 3 (i ′ = 90 • ) = 0.511M ⊙ .

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Section: O-c Diagram Analysesmentioning

confidence: 96%

Section: O-c Diagram Analysesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Multi-color light curves and orbital period research of eclipsing binary V1073 Cyg

Tian

Zhu

Qian

et al. 2018

Res. Astron. Astrophys.

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“…as i) night-to-night variations and unequal maxima in the LCs indicating spots on the surface of the components (V1073 Cyg -Yang & Liu 2000; V2150 Cyg -Yesilyaprak 2002 LS Del -Demircan et al 1991 SW Lac -Gazeas et al 2005, Şenavcı et al 2011 EX Leo -Pribulla et al 2002, Zola et al 2010; V351 Peg -Albayrak et al 2005; V357 Peg -Ekmekçi et al 2012; OU Ser -Pribulla & Vanko 2002, Yesilyaprak 2002; V781 Tau -Cereda et al 1988, Kallrath et al 2006, Li et al 2016, ii) longterm modulation in the orbital period, which could be connected to magnetic cycles (KR Com -Zasche & Uhlář 2010; V1073 Cyg - V781 Tau -Li et al 2016), or, iii) X-ray flux coming from the direction of the system indicating coronal activity (KR Com -Kiraga 2012; LSDel - Ste ¸pień et al 2001, Szczygieł et al 2008, Kiraga 2012 SW Lac -Cruddace & Dupree 1984, McGale et al 1996, Ste ¸pień et al 2001, Xing et al 2007 EX Leo -Kiraga 2012; OU Ser -Kiraga 2012; V781 Tau -Ste ¸pień et al 2001, Kiraga 2012). …”

mentioning

confidence: 99%

Chromospheric activity in bright contact binary stars

Mitnyan

Szalai

Bódi

et al. 2020

A&A

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Context. Studying chromospheric activity of contact binaries is an important way of revealing the magnetic activity processes of these systems. An efficient but somewhat neglected method for that is to follow the changes of the Hα line profiles via optical spectroscopy. Aims. Our goal was to perform a comprehensive preliminary analysis based on the optical spectral signs of chromospheric activity on the largest sample of contact binaries to date. Methods. We collected optical echelle spectra on 12 bright contact binaries at 17 nights. We derived new radial velocity curves from our observations. For quantifying the apparent chromospheric activity levels of the systems, we subtracted self-constructed synthetic spectra from the observed ones and measured the equivalent widths of the residual Hα-profiles at each observed epoch. Our wellsampled data set allowed us to study the short-term variations of chromospheric activity levels as well as to search for correlations between them and some basic physical parameters of the systems. Results. Fitting the radial velocity curves, we re-determined the mass ratios and systemic velocities of all observed objects. We found that chromospheric activity levels of the studied systems show various changes during the orbital revolution: we see either flat, or onepeaked, or two-peaked distributions of equivalent width vs. the orbital phase. The first case means that the activity level is probably constant, while the latter two cases suggest the presence of one or two active longitudes at the stellar surfaces. Our correlation diagrams show that mean chromospheric activity levels may be in connection with orbital periods, B−V color indices, inverse Rossby numbers, and temperature differences of the components. At the same time, no clear trend is visible with respect to mass ratios, inclinations and fill-out factors of the systems. A-and W-type contact binaries in our sample show similar distributions at each of the studied correlation diagrams.

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