Infrared Excess in the Be Star Delta Scorpii

We present infrared photometric observations of the Be binary system delta Scorpii obtained in 2006. The J,H and K magnitudes are the same within the errors compared to observations taken 10 months earlier. We derive the infrared excess from the observation and compare this to the color excess predicted by a radiative equilibrium model of the primary star and its circumstellar disk. We use a non-LTE computational code to model the gaseous envelope concentrated in the star's equatorial plane and calculate the expected spectral energy distribution and Halpha emission profile of the star with its circumstellar disk. Using the observed infrared excess of delta Sco, as well as Halpha spectroscopy bracketing the IR observations in time, we place constraints on the radial density distribution in the circumstellar disk. Because the disk exhibits variability in its density distribution, this work will be helpful in understanding its dynamics.Comment: 12 pages, 14 figures, to be published in PASP May 200

Imaging Disk Distortion of Be Binary System δ Scorpii near Periastron

The highly eccentric Be binary system δ Sco reached periastron during early 2011 July, when the distance between the primary and secondary was a few times the size of the primary disk in the H band. This opened a window of opportunity to study how the gaseous disks around Be stars respond to gravitational disturbance. We first refine the binary parameters with the best orbital phase coverage data from the Navy Precision Optical Interferometer. Then we present the first imaging results of the disk after the periastron, based on seven nights of five telescope observations with the MIRC combiner at the CHARA array. We found that the disk was inclined 27 ##IMG## [http://ej.iop.org/icons/Entities/fdg.gif] {fdg 6 ± 6 ##IMG## [http://ej.iop.org/icons/Entities/fdg.gif] {fdg 0 from the plane of the sky, had a half-light radius of 0.49 mas (2.2 stellar radii), and consistently contributed 71.4% ± 2.7% of the total flux in the H band from night to night, suggesting no ongoing transfer of material into the disk during the periastron. The new estimation of the periastron passage is UT 2011 July 3 07:00 ± 4:30. Re-analysis of archival VLTI-AMBER interferometry data allowed us to determine the rotation direction of the primary disk, constraining it to be inclined either ~119° or ~171° relative to the orbital plane of the binary system. We also detect inner disk asymmetries that could be explained by spot-like emission with a few percent of the disk total flux moving in Keplerian orbits, although we lack sufficient angular resolution to be sure of this interpretation and cannot yet rule out spiral density waves or other more complicated geometries.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98576/1/0004-637X_757_1_29.pd

B[e] Stars with Warm Dust: Revealing the Nature of Unclassified B[e] Stars and Expanding the Family

Until recently, unclassified B[e] stars represented half of the entire B[e] group. Our study of these objects with strong emission-line spectra and IRAS fluxes, decreasing toward longer wavelengths, resulted in a suggestion that they currently form dust in their envelopes. The objects have been tentatively called B[e] stars with warm dust (B[e]WD). Their luminosity range (?3 orders of magnitude) is much larger compared to previous suggestions that dust formation occurs only near very luminous hot stars. A significant fraction of B[e]WD are recognized or suspected binaries. The group has been expanded with both previously detected hot emission-line stars with IR fluxes, typical for confirmed B[e]WD, and new candidates, found in recent all-sky surveys. Currently the number of B[e]WD members and candidates is ?60 with an opportunity to find more in existing stellar catalogs. Main observational and physical properties of B[e]WD and their envelopes are summarized. Our results on newly found group members are presented. Partially based on observations obtained at the Canada-France-Hawaii Telescope (CFHT).Fil: Miroshnichenko, A. S.. University of North Carolina at Greensboro; Estados UnidosFil: Bernabei, S.. Istituto Nazionale di Astrofisica; ItaliaFil: Bjorkman, K. S.. University Of Toledo (utoledo); Estados UnidosFil: Chentsov, E. L.. Russian Academy of Sciences; RusiaFil: Klochkova, V. G.. Russian Academy of Sciences; RusiaFil: Gray, R. O.. Appalachian State University; Estados UnidosFil: Levato, H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Hinkle, K. H.. National Optical Astronomy Observatory; Estados UnidosFil: Kuratov, K. S.. Fesenkov Astrophysical Institute; KazajistánFil: Kusakin, A. V.. Universitetskij pr; RusiaFil: García Lario, P.. European Space Astronomy Centre; EspañaFil: Perea Calderón, J. V.. European Space Astronomy Centre; EspañaFil: Polcaro, V. F.. Istituto di Astrofisica Spaziale e Fisica Cosmica; ItaliaFil: Viotti, R. F.. Istituto di Astrofisica Spaziale e Fisica Cosmica; ItaliaFil: Norci, L.. Dublin City University; IrlandaFil: Manset, N.. Canada France Hawaii Telescope; Estados UnidosFil: Men’shchikov, A. B.. Saint Mary’s University; CanadáFil: Rudy, R. J.. The Aerospace Corporation; Estados UnidosFil: Lynch, D. K.. The Aerospace Corporation; Estados UnidosFil: Venturini, C. C.. The Aerospace Corporation; Estados UnidosFil: Mazuk, S.. The Aerospace Corporation; Estados UnidosFil: Puetter, R. C.. University of California; Estados UnidosFil: Perry, R. B.. National Aeronautics and Space Administration; Estados UnidosFil: Gandet, T. L.. Lizard Hollow Observatory; Estados Unido

Toward Understanding the B[e] Phenomenon. II. New Galactic FS CMa Stars

FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as unclassified B[e] stars or B[e] stars with warm dust (B[e]WD) until recently. They exhibit strong emission-line spectra and strong IR excesses, most likely due to recently formed circumstellar dust. These properties have been suggested to be due to ongoing or recent rapid mass exchange in binary systems with hot primaries and various types of secondaries. The first paper of this series reported an analysis of the available information about previously known Galactic objects with the B[e] phenomenon, the initial selection of the FS CMa group objects, and a qualitative explanation of their properties. This paper reports the results of our new search for more FS CMa objects in the IRAS Point Source Catalog. We present new photometric criteria for identifying FS CMa stars as well as the first results of our observations of nine new FS CMa group members. With this addition, the FS CMa group has now 40 members, becoming the largest among the dust-forming hot star groups. We also present nine objects with no evidence for the B[e] phenomenon, but with newly discovered spectral line emission and /or strong IR excesses.Fil: Miroshnichenko, A. S.. The University Of North Carolina At Greensboro; Estados UnidosFil: Manset, N.. Canada France Hawaii Telescope; Estados UnidosFil: Kusakin, A.V.. Lomonosov Moscow State University; Rusia. Fesenkov Astrophysical Institute; RusiaFil: Chentsov, E.L.. Russian Academy Of Sciences; RusiaFil: Klochkova, V. G.. Russian Academy Of Sciences; RusiaFil: Zharikov, S. V.. Universidad Nacional Autónoma de México; MéxicoFil: Gray, R. O.. Appalachian State University (appstate);Fil: Grankin, K. N.. Ulugh Beg Astronomical Institute Uzbekistan Academy Of Sciences; UzbekistánFil: Gandet, T. L.. Lizard Hollow Observatory; Estados UnidosFil: Bjorkman, K. S.. University Of Toledo (utoledo); Estados UnidosFil: Rudy, R. J.. The Aerospace Corporation; Estados UnidosFil: Lynch, D. K.. The Aerospace Corporation; Estados UnidosFil: Venturini, C. C.. The Aerospace Corporation; Estados UnidosFil: Mazuk, S.. The Aerospace Corporation; Estados UnidosFil: Puetter, R. C.. University of California at San Diego; Estados UnidosFil: Perry, R. B.. National Aeronautics and Space Administration; Estados UnidosFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Bernabei, S.. Istituto Nazionale di Astrofisica; ItaliaFil: Polcaro, V. F.. Istituto Nazionale di Astrofisica; ItaliaFil: Viotti, R. F.. Istituto Nazionale di Astrofisica; ItaliaFil: Norci, L.. Dublin City University; IrlandaFil: Kuratov, K. S.. Fesenkov Astrophysical Institute; Kazajistá

EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

V669 Cep: A new binary system with a B[e] star

We present the results of optical and near-IR spectroscopic and broadband multicolour photometric observations of the emission-line object V669 Cep. We find evidence that it contains a hot, low luminosity, B4–B6 star and a cool companion (most likely late-type giant). Significant variations of the Hα line strength are detected on a timescale of months. The emission-line spectrum and strong IR-excess indicate a large amount of circumstellar gas and dust in the system. The spectral energy distribution in the near-IR region and the absence of late-type star features in the optical spectrum indicates that the cool star is heavily obscured by circumstellar dust, while the hot star is much less affected by reddening. The system is located at 1–1.5 kpc from the Sun in the local spiral arm. We suggest that V669 Cep is an evolved and probably mass exchanging binary system, a member of the group of Be stars with warm dust

B[e] Stars with Warm Dust: Revealing the Nature of Unclassified B[e] Stars and Expanding the Family

Until recently, unclassified B[e] stars represented half of the entire B[e] group. Our study of these objects with strong emission-line spectra and IRAS fluxes, decreasing toward longer wavelengths, resulted in a suggestion that they currently form dust in their envelopes. The objects have been tentatively called B[e] stars with warm dust (B[e]WD). Their luminosity range (?3 orders of magnitude) is much larger compared to previous suggestions that dust formation occurs only near very luminous hot stars. A significant fraction of B[e]WD are recognized or suspected binaries. The group has been expanded with both previously detected hot emission-line stars with IR fluxes, typical for confirmed B[e]WD, and new candidates, found in recent all-sky surveys. Currently the number of B[e]WD members and candidates is ?60 with an opportunity to find more in existing stellar catalogs. Main observational and physical properties of B[e]WD and their envelopes are summarized. Our results on newly found group members are presented. Partially based on observations obtained at the Canada-France-Hawaii Telescope (CFHT).Fil: Miroshnichenko, A. S.. University of North Carolina at Greensboro; Estados UnidosFil: Bernabei, S.. Istituto Nazionale di Astrofisica; ItaliaFil: Bjorkman, K. S.. University Of Toledo (utoledo); Estados UnidosFil: Chentsov, E. L.. Russian Academy of Sciences; RusiaFil: Klochkova, V. G.. Russian Academy of Sciences; RusiaFil: Gray, R. O.. Appalachian State University; Estados UnidosFil: Levato, H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Hinkle, K. H.. National Optical Astronomy Observatory; Estados UnidosFil: Kuratov, K. S.. Fesenkov Astrophysical Institute; KazajistánFil: Kusakin, A. V.. Universitetskij pr; RusiaFil: García Lario, P.. European Space Astronomy Centre; EspañaFil: Perea Calderón, J. V.. European Space Astronomy Centre; EspañaFil: Polcaro, V. F.. Istituto di Astrofisica Spaziale e Fisica Cosmica; ItaliaFil: Viotti, R. F.. Istituto di Astrofisica Spaziale e Fisica Cosmica; ItaliaFil: Norci, L.. Dublin City University; IrlandaFil: Manset, N.. Canada France Hawaii Telescope; Estados UnidosFil: Men’shchikov, A. B.. Saint Mary’s University; CanadáFil: Rudy, R. J.. The Aerospace Corporation; Estados UnidosFil: Lynch, D. K.. The Aerospace Corporation; Estados UnidosFil: Venturini, C. C.. The Aerospace Corporation; Estados UnidosFil: Mazuk, S.. The Aerospace Corporation; Estados UnidosFil: Puetter, R. C.. University of California; Estados UnidosFil: Perry, R. B.. National Aeronautics and Space Administration; Estados UnidosFil: Gandet, T. L.. Lizard Hollow Observatory; Estados Unido