U, B, V photometry of SX Cassiopeiae

Shao, C. Y.

doi:10.1086/110254

Cited by 12 publications

(4 citation statements)

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“…This is welldemonstrated in the classic work on SX Cas by Struve (1944) and the long observational history thereafter (see e.g. Shao 1967;Koch 1972;Plavec et al 1982;Andersen et al 1988, and the references therein).…”

Section: Introductionmentioning

confidence: 60%

UBVRI polarimetry of the massive interacting binary SX Cassiopeiae: modeling the electron-scattering circumstellar envelope

Piirola

Berdyugin

Coyne

et al. 2006

A&A

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Aims. We perform a study of the structure, density, and distribution of ionized circumstellar gas in the strongly interacting binary SX Cas. Methods. We apply our new model codes for electron scattering in circumstellar matter to analyze a previously unpublished, extensive linear polarization data set for SX Cas, collected during four successive observing periods in 1981-84 at the Crimean Astrophysical Observatory. These data are complemented by our polarization observations carried out in 2000 and 2005 with the KVA-60 telescope at La Palma. Results. A clear, phase-locked pattern of polarization variations over the 36.6-day orbital period is revealed in each season, showing significant 1st and 2nd harmonic Fourier components and pronounced effects in the U and B bands at the primary eclipse, when the hot component and the surrounding circumstellar matter are obscured by the companion star. Seasonal variability is also found, but the major features of the polarization curves are well explained by a model with an extended scattering region on the trailing side of the accreting star, where the stream from the companion hits the accretion disk. No significant polarized flux is detected from the disk. We interpret this as being due to multiple scattering and strong absorption effects in the optically thick medium, which reduce the polarization of the light emerging from the disk to low levels. The modeled scattering region is above the orbital plane by about 10 • , as seen from the center of the mass gainer. We attribute this to dominant electron scattering taking place on the upper side of an optically and geometrically thick accretion disk seen at an inclination i ∼ 78 • by the observer.

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Section: Introductionmentioning

confidence: 60%

UBVRI polarimetry of the massive interacting binary SX Cassiopeiae: modeling the electron-scattering circumstellar envelope

Piirola

Berdyugin

Coyne

et al. 2006

A&A

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“…For both 2010 and 2050, the simulations are conducted in January, April, July, and October, which represent winter, spring, summer, and fall, following a number of previous studies. [28][29][30] We apply the model to two nested domains: Domain 1 covers the western United States and its surrounding areas at a 12 × 12 km 2 horizontal resolution; Domain 2 covers California with a 4 × 4 km 2 resolution (Figure 1). The vertical resolution of the WRF-Chem includes 24 layers from the surface to 100 hPa, with denser layers at lower altitudes to resolve the planetary boundary layer (PBL).…”

Section: Development Of Decarbonization Scenariosmentioning

confidence: 99%

“…When the PM 2.5 -and O 3 -related mortalities are taken together, 12 100 (9600-14 600) and 2800 (2300-3400) premature deaths are estimated to be avoided annually compared with the BAU levels as a result of decarbonization strategies envisaged in the DD1 and DD2 scenarios, respectively. The corresponding monetized health cobenefits are estimated to be about 109 (87-131) and 25 (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) billion of 2017 U.S. dollars.…”

Section: Health Cobenefit Of Decarbonization Policiesmentioning

confidence: 99%

Air Quality and Health Cobenefits of Different Deep Decarbonization Pathways in California

Zhao

Wang

Jiang

et al. 2019

Environ. Sci. Technol.

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As the world's fifth-largest economy, California has committed to reduce its greenhouse gas (GHG) emissions by 80% below 1990 levels by 2050. While previous studies have shown that GHG reductions could synergistically decrease air pollutant emissions and protect public health, limited research has been conducted to compare the health cobenefits of different technology pathways toward deep decarbonization. Using an integrated approach that combines energy and emission technology modeling, high-resolution chemical transport simulation, and health impact assessment, we find that achievement of the 80% GHG reduction target would bring substantial air quality and health cobenefits. The cobenefits, however, highly depend on the selected technology pathway largely because of California's relatively clean energy structure. Compared with the business-as-usual levels, a decarbonization pathway that focuses on electrification and clean renewable energy is estimated to reduce concentrations of fine particulate matter (PM 2.5) by 18-37% in major metropolitan areas of California and subsequently avoid about 12 100 (9600-14 600) premature deaths. In contrast, only a quarter of such health cobenefits, i.e., 2800 (2300-3400) avoided deaths, can be achieved through a pathway focusing more on combustible renewable fuels. After subtracting the cost, the net monetized benefit of the electrification-focused pathway still *

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“…For SX Cas (Paper I) , we have studied the light curves by Shao (1967), using the Wilson-Devinney (1971) program with the (unproved) assumption of near-critical rotation for the primary component, but without explicit allowance for the disk. For RX Cas, Paper II provides new UBVRI photometry by V. Piirola, analyzed with the method by Pavlovski and Kriz (1985), which includes Roche geometry, critical rotation of the primary, and a simple disk model.…”

Section: Photometric Elementsmentioning

confidence: 99%

Fundamental Parameters of the W Serpentis Stars

Andersen

Nordström

1989

International Astronomical Union Colloquium

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Application of digital cross-correlation spectroscopy to the spectra of the W Serpentis binaries SX Cas and RX Cas has allowed an accurate determination of the orbits and rotations of the (mass-losing) K-subgiant secondary components. The distortion of the primary radial-velocity curves due to the influence of the prominent accretion disks in these systems has been modelled to first order. This enables us to estimate K1 , and thereby the mass ratio q ≈ 0.30, to within ~±20%. The absolute radii of the secondaries are derived independently from the observed rotations and periods, assuming synchronous rotation. They show that the stars fill their Roche lobes, or at least very nearly so. Rough fits to the available photometry shows both primaries to be unevolved mid-B stars; that in RX Cas appears completely obscured by the disk. Preliminary spectroscopic data for W Ser and W Cru show some promise for similar analyses of these systems.

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U, B, V photometry of SX Cassiopeiae

Cited by 12 publications

References 0 publications

UBVRI polarimetry of the massive interacting binary SX Cassiopeiae: modeling the electron-scattering circumstellar envelope

UBVRI polarimetry of the massive interacting binary SX Cassiopeiae: modeling the electron-scattering circumstellar envelope

Air Quality and Health Cobenefits of Different Deep Decarbonization Pathways in California

Fundamental Parameters of the W Serpentis Stars

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