{"id":2911,"date":"2024-05-20T18:53:00","date_gmt":"2024-05-20T18:53:00","guid":{"rendered":"https:\/\/araucaria.camk.edu.pl\/?p=2911"},"modified":"2024-09-30T19:29:58","modified_gmt":"2024-09-30T19:29:58","slug":"physical-properties-of-the-quadruple-system-with-early-type-eclipsing-binary","status":"publish","type":"post","link":"https:\/\/araucaria.camk.edu.pl\/index.php\/2024\/05\/20\/physical-properties-of-the-quadruple-system-with-early-type-eclipsing-binary\/","title":{"rendered":"Physical properties of the quadruple system with early-type eclipsing binary"},"content":{"rendered":"\n

An early-type eclipsing binary turns out to be a hierarchical quadruple system. Analysis of its complex configuration, although not easy, yields masses, radii, and temperatures of the inner binary, and mass estimations of the two outermost components.<\/p>\n\n\n\n

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Toward Early-type Eclipsing Binaries as Extragalactic Milestones. III. Physical Properties of the O-type Eclipsing Binary OGLE LMC-ECL-21568 in a Quadruple System<\/strong><\/h3>\n\n\n\n

M. Taormina, R.P. Kudritzki, B. Pilecki, G. Pietrzy\u0144ski, I.B. Thompson, J. Puls,M. G\u00f3rski, B. Zgirski, D. Graczyk, W. Gieren, G. Hajdu<\/em><\/p>\n\n\n\n

2024, ApJ 967, 64<\/a><\/p>\n\n\n\n

These results come from a comprehensive study of an eclipsing O-type binary (Aa+Ab), OGLE LMC-ECL-21568, with the inner orbital period P<\/em>orb, A<\/sub> = 3.2254367 days that forms a higher-order hierarchical system in a configuration of (A+B)+C.<\/p>\n\n\n

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Radial velocity curve of the inner (Aa-Ab) system’s center of mass and the range of possible velocities of the tertiary component.<\/figcaption><\/figure><\/div>\n\n
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O\u2212C diagram showing the phase shifts between the data from around the given date and the average model. The influence of two extra components can be seen. The red line is the fit to the LTTE induced by the third
and fourth body.<\/figcaption><\/figure><\/div>\n\n\n

We derived masses, radii, and temperatures of the Aa+Ab binary, and by analysing their radial velocities, we found a spectroscopic orbit of A in the outer A+B system with P<\/em>orb, A+B<\/sub> = 195.8 days. In the O\u2013C analysis, we found another component orbiting the A+B system with P<\/em>AB+C<\/sub> = 2550 days. From the total mass of the inner binary and its outer orbit, we estimated the mass of the third object, M<\/em>B<\/sub> = 10.7 M\u2299<\/sub>. From the light travel time effect fit to the O\u2212C data, we obtained the limit for the mass of the fourth component, M<\/em>C<\/sub> = 7.3 M\u2299<\/sub>. <\/p>\n\n\n\n

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Evolutionary constraints on the third and fourth objects. Plots show MESA evolutionary tracks with ZAMS masses of 7.4 (blue) and 11 (green) M\u2299<\/sub>, corresponding to the minimum masses of the fourth and third objects, respectively.<\/figcaption><\/figure>\n\n\n\n

These extra components contribute about 20%\u201330% (increasing with wavelength) to the total system light. From the comparison of model spectra with the multiband photometry, we derived the distance modulus to the system of 18.59 \u00b1 0.06 mag, and the reddening of 0.16 \u00b1 0.02 mag.<\/p>\n\n\n\n

This work is part of our ongoing project, which aims to calibrate the surface brightness-color relation for early type stars. Previous papers:<\/p>\n\n\n\n