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* , †

• DOI: 10.3847/1538-4357/ad3af0
• Publication Date: 2024-05-17T20:00:36Z
• Authors: Mónica Taormina; R.-P. Kudritzki; B. Pilecki; G. Pietrzyński; I. B. Thompson; J. Puls; M. Górski; B. Zgirski; D. Graczyk; W. Gieren; G. Hajdu
• Keywords: QB460-466; Early-type stars; O stars; Astrophysics - Solar and Stellar Astrophysics; Eclipsing binary stars; FOS: Physical sciences; Detached binary stars; Multiple stars; Astrophysics; Large Magellanic Cloud; Solar and Stellar Astrophysics (astro-ph.SR)

Abstract We present the results from a complex study of an eclipsing O-type binary (Aa+Ab) with orbital period P A = 3.2254367 days that forms part higher-order multiple system in configuration (A+B)+C. derived masses Aa+Ab M 1 19.02 ± 0.12 and 2 17.50 0.13 ⊙ , radii R 7.70 0.05 6.64 0.06 temperatures T 34,250 500 K 33,750 K. From analysis radial velocities, we found spectroscopic orbit outer A+B 195.8 ( / ≈ 61). In O − C analysis, confirmed this another component orbiting AB+C 2550 13). total mass inner its orbit, estimated third object, B ≳ 10.7 . light travel time effect fit to data, obtained limit for fourth component, 7.3 These extra components contribute about 20%–30% (increasing wavelength) light. comparison model spectra multiband photometry, distance modulus 18.59 mag, reddening 0.16 0.02 V 3.2. This work is our ongoing project, which aims calibrate surface brightness–color relation early-type stars.