New insights on the massive interacting binary UU Cassiopeiae

Abstract

We present the results of the study of the close binary UU Cassiopeiae based on previously published multi wavelength photometric and spectroscopic data. Based on eclipse timings of the last 117 years, we find an improved orbital period of ${\mathrm{P}}_{\mathrm{o}}=8.519296(8)$ d. In addition, we find a long cycle of length $T$ $\sim$ 270 d in the $I_c$-band data. There is no evidence for orbital period change during the last century, suggesting that the rate of mass loss from the system or mass exchange between the stars should be small. Sporadic and rapid brightness drops of up to $\Delta$$V$ = 0.3 mag are detected during the whole orbital cycle and infrared photometry clearly suggests the presence of circumstellar matter. We model the orbital light curve of 11 published datasets fixing the mass ratio and cool star temperature from previous spectroscopic work; $q$= 0.52 and $T_c$= 22 700 K. We find a system seen at angle 74 degrees with a stellar separation of 52 ${\mathrm{R}}_{\odot }$, a temperature for the hotter star $T_h$= 30 200 $K$ and stellar masses 17.4 and 9 ${\mathrm{M}}_{\odot }$ , radii 7.0 and 16.9 ${\mathrm{R}}_{\odot }$ and surface gravities log g = 3.98 and 2.94, for the hotter and cooler star, respectively. We find an accretion disk surrounding the more massive star, with a radius of 21 ${\mathrm{R}}_{\odot }$ and vertical thickness in its outer edge of 6.5 ${\mathrm{R}}_{\odot }$, mostly occulting the hotter star. Two active regions hotter than the surrounding disk are found, one located roughly in the expected position where the stream impacts the disk and the other one in the opposite side of the disk. Changes are observed in parameters of the disk and spots in different datasets.

arXiv commentAccepted for publication in Astronomy and Astrophysics, 10 pages, 11 figures

References in corpus (14)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The SIMBAD astronomical database
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Progenitors of gravitational wave mergers: Binary evolution with the stellar grid-based code ComBinE
• The incidence of stellar mergers and mass gainers among massive stars
• Which Massive stars are Gamma-Ray Burst Progenitors?
• Double-periodic blue variables in the Magellanic Clouds
• A cyclic bipolar wind in the interacting binary V393 Scorpii
• On the accretion disc and evolutionary stage of beta Lyrae
• Fundamental parameters of the close interacting binary HD170582 and its luminous accretion disc
• A representative sample of Be stars IV: Infrared Photometry and the Continuum Excess
• On the long cycle variability of the Algol OGLE-LMC-DPV-065 and its stellar, orbital and disk parameters
• The INTEGRAL-OMC Scientific Archive

Cited by in corpus (6)

• Model for the long and orbital brightness variability of the $\beta$ Lyrae type binary OGLE-BLG-ECL-157529
• V4142 Sgr: a Double Periodic Variable with an accretor surrounded by the accretion-disk's atmosphere
• Stellar and accretion disk parameters of the close binary HD 50526
• Spectroscopy of the massive interacting binary UU Cassiopeiae
• Cyclic light variations and accretion disk evolution in the LMC eclipsing binary OGLE-LMC-DPV-062
• Long Photometric Cycles in Double Periodic Variables from Nodal Precession of a Tilted Accretion Disk