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Jassur, D. M. Z.; Khaledian, M.S.; Kermani, M. H.

doi:10.1023/a:1013136400096

Cited by 2 publications

(3 citation statements)

References 2 publications

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“…From our analysis, we may conclude that AI Dra is an eclipsing semidetached binary with partial eclipses, thus eliminating the previously suggested occultation solution. As shown in Table 9, the secondary fills its Roche lobe, in disagreement with the result of Jassur et al (2001) that both components of AI Dra are located inside their Roche lobes.…”

Section: Discussioncontrasting

confidence: 64%

“…So we decided to adopt the first set of ( M 1 , q ) as initial parameters in the light‐curve fits (the M 1 value is fixed while q is left free in the fits). Both of these values of M 1 are much smaller than the value M 1 = 3.40 M ⊙ adopted by Degirmenci et al (2000) in their BV light‐curve analysis, being closer to the value adopted by Jassur et al (2001), M 1 = 2.98 M ⊙ for their UBV data.…”

Section: Discussionsupporting

confidence: 60%

“…From the O–C diagram of the times of eclipse, they suggested a third stellar component in the system, with an orbital period of about 23 yr, but the analysis of their B and V light curves does not show any influence of a third light contribution on the orbital and stellar parameters obtained. Jassur, Khaledian & Kermani (2001) have presented complete UBV light curves. Their analysis, carried out with the wd code, indicated that both components are within their Roche lobes.…”

Section: Introductionmentioning

confidence: 99%

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The fundamental parameters of the Algol binary AI Draconis revisited

Lázaro¹,

Martínez‐País²,

Arévalo³

2004

Monthly Notices of the Royal Astronomical Society

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We present the results of an analysis of our infrared light curves of the Algol-type binary AI Draconis in the J, H and K bands, and of published light curves in the B, V and Strömgren uvby bands, together with spectra obtained by us. The analysis of the light curves was carried out using a code based on ATLAS model atmospheres and Roche geometry.The small contribution of the secondary cool component to the total light of the system in the visible, producing light curves with very shallow secondary eclipses, makes the stellar and orbital parameters derived from light-curve analysis in the visible spectral range uncertain. The larger contribution of the secondary star to the infrared fluxes makes this range particularly well suited to the derivation of precise orbital and stellar parameters in binaries of Algol type. From the simultaneous solution of the infrared JHK light curves, we derive the following absolute orbital and stellar parameters for the two components: T eff,1 = 10 160 ± 160 K, R eq,1 = 2.12 ± 0.04 R , log( g ) 1 = 4.23; T eff,2 = 5586 ± 110 K, R eq,2 = 2.36 ± 0.04 R , log( g ) 2 = 3.76; M 1 = 2.86 ± 0.09 M , q = M 2 /M 1 = 0.44 ± 0.03; a = 7.62 ± 0.09 R , i = 76.53 • ± 0.3 • , e 0.0. Here, T eff and log( g ) indicate average surface values, R eq is the equivalent radius of the deformed star and a is the orbital size.In our light-curve solutions, the secondary star of AI Dra fills its Roche lobe (as also indicated by the spectroscopy), thus discounting claims, based on UBV light curves, that both components of the binary are located within their Roche lobes. The visible and infrared photometry show no evidence of any significant infrared excess in the system, and the distance of AI Dra is estimated as d = 169 ± 17 pc.Based on the spectra of AI Dra and template stars in the ranges 8210-9060, 6250-7130 and 4040-4920 Å, we classify the stellar components of AI Dra and find that the most probable spectral types are A0V (or perhaps A1V) for the primary and F9.5V for the secondary (although it could reach as far as G4V), respectively. From our spectroscopic observations, the spectral evolution of AI Dra with orbital phase is also presented. Furthermore, we obtain the projected rotational velocity of the secondary, whose value turns out to be compatible with the star filling its Roche lobe.

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Section: Discussioncontrasting

confidence: 64%