An analysis of the light curves of four W UMa-type stars

Lafta, S. J.; Grainger, J. F.

doi:10.1007/bf00637771

Cited by 6 publications

(7 citation statements)

References 23 publications

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“…The mass ratio converged to a value of q = 0.1289 in the final solution. This solution indicates that FG Hya is an A-type W UMa binary, in agreement with the results published by Mochnacki & Doughty (1972), Twigg (1979), Lafta & Grainger (1986), Jabbar et al (1986) and Yang et al (1991). The photometric parameters are listed in Table 5, where Star 1 indicates a more massive component and Star 2 is one of less mass.…”

Section: Photometric Solutionssupporting

confidence: 89%

“…The external error of the derived radial velocities from their DDO observations is smaller than 1.8 km s −1 . The derived mass ratio from their better phase covered radial velocity curve is 0.112(04) which is close to those from the photometric solutions presented by Mochnacki et al (1972), Twigg (1979), Lafta et al (1986), Jabbar et al (1986) and Yang et al (1991).…”

Section: Introductionsupporting

confidence: 78%

“…The photometric solutions were obtained by Mochnacki et al (1972), Twigg (1979), Lafta et al (1986), Jabbar et al (1986) and Yang et al (1991). Their studies indicate that the system is an A-type overcontact W UMa binary.…”

Section: Introductionmentioning

confidence: 99%

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CCD photometric study of the contact binary FG Hydrae

YL¹,

QY²

2000

Astron. Astrophys. Suppl. Ser.

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Section: Photometric Solutionssupporting

confidence: 89%

Section: Introductionsupporting

confidence: 78%

See 1 more Smart Citation

CCD photometric study of the contact binary FG Hydrae

YL¹,

QY²

2000

Astron. Astrophys. Suppl. Ser.

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“…Observations of a complete light curve made by Binnendijk (1963) led to an improved orbital period determination. Theoretical models of the system were presented by Lafta & Grainger (1986) and Mahdy, Hamdy & Soliman (1985). Mochnacki & Doughty (1972), Twigg (1979) and Yang et al (1991), analysing the photometric light curves of the system, concluded that FG Hya must have a very small mass ratio.…”

Section: Introductionmentioning

confidence: 99%

Physical parameters of components in close binary systems - VII

Zoła

Gazeas

Kreiner

et al. 2010

Monthly Notices of the Royal Astronomical Society

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We present results of the modelling of multicolour light curves of 10 contact binary systems: V376 And, V523 Cas, CC Com, BX Dra, FG Hya, UZ Leo, XY Leo, AM Leo, EX Leo and RT LMi. The solutions resulted in a contact configuration for all systems. We found only FG Hya and UZ Leo to be in deep contact, the latter almost filling the outer critical lobe. The absolute parameters of the components have been determined with an accuracy of about a few per cent based on combined photometric and radial velocity curves, enlarging the sample of systems to 58 for which the physical parameters have been obtained in a uniform way. All but three systems (BX Dra, AM Leo and RT LMi) show asymmetries and peculiarities in the observed light curves, interpreted as resulting from their magnetic activity.

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“…Qian, Liu & Yang 1999; Yang & Liu 2000). Photometric solutions of the system were derived by Mochnacki & Doughty (1972), Twigg (1979), Jabbar, Fleyeh & Al Razzaz (1986), Lafta & Grainger (1986), Yang et al (1991) and Yang & Liu (2000). The first spectroscopic parameters for both components were determined by Lu & Rucinski (1999).…”

Section: Introductionmentioning

confidence: 99%

Improved astrophysical parameters for the overcontact binary FG Hydrae

Qian

Yang

2005

Monthly Notices of the Royal Astronomical Society

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Photometric data on FG Hya obtained in 2002 and 2004 are presented. Three data sets show the exchange between A‐type, W‐type and the variable O'Connell effects. The photometric mass ratio (q= 0.1115 ± 0.0003) derived from B and V light curves is almost the same as the spectroscopic mass ratio (qsp= 0.112 ± 0.004). The new photometric solutions reveal that FG Hya is a deep overcontact binary system (f= 85.6 ± 1.8 per cent) with a spotted massive component. A period investigation, based on all available photoelectric or CCD times of light minimum, shows that the O–C curve of FG Hya can be explained as a combination of a secular period decrease and a cyclic variation with a period of 36.4 yr and an amplitude of 0.0289 d. By comparing the variation of the depth of the primary minimum with the change of the cyclic period, it is discovered that both of them may vary with the same cycle length of 36.4 yr and in the same phase. The variation of the light curve, the spotted primary component and the connection between the cyclic period change and the depth of the primary minimum, all may suggest that the G0‐type component displays solar‐type magnetic activity with a 36.4‐yr cycle length. The long‐time period decrease is interpreted by mass transfer from the more massive component to the less massive one or/and angular momentum loss due to mass outflow from the outer Lagrangian point.

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An analysis of the light curves of four W UMa-type stars

Cited by 6 publications

References 23 publications

CCD photometric study of the contact binary FG Hydrae

CCD photometric study of the contact binary FG Hydrae

Physical parameters of components in close binary systems - VII

Improved astrophysical parameters for the overcontact binary FG Hydrae

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