The expanding fireball of Nova Delphini 2013.

A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common-envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion. Studying the structure of novae during the earliest phases is challenging because of the high spatial resolution needed to measure their small sizes. Here we report near-infrared interferometric measurements of the angular size of Nova Delphini 2013, starting one day after the explosion and continuing with extensive time coverage during the first 43 days. Changes in the apparent expansion rate can be explained by an explosion model consisting of an optically thick core surrounded by a diffuse envelope. The optical depth of the ejected material changes as it expands. We detect an ellipticity in the light distribution, suggesting a prolate or bipolar structure that develops as early as the second day. Combining the angular expansion rate with radial velocity measurements, we derive a geometric distance to the nova of 4.54 ± 0.59 kiloparsecs from the Sun.

HD 181068: a red giant in a triply eclipsing compact hierarchical triple system.

Hierarchical triple systems comprise a close binary and a more distant component. They are important for testing theories of star formation and of stellar evolution in the presence of nearby companions. We obtained 218 days of Kepler photometry of HD 181068 (magnitude of 7.1), supplemented by ground-based spectroscopy and interferometry, which show it to be a hierarchical triple with two types of mutual eclipses. The primary is a red giant that is in a 45-day orbit with a pair of red dwarfs in a close 0.9-day orbit. The red giant shows evidence for tidally induced oscillations that are driven by the orbital motion of the close pair. HD 181068 is an ideal target for studies of dynamical evolution and testing tidal friction theories in hierarchical triple systems.

Hidrotórax hepático / Hepatic hydrothorax

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[Spontaneous resolution of extensive superior mesenteric and portal vein thrombosis. A case report]. / Resolución espontánea de una trombosis extensa de las venas mesentérica superior y porta. Caso clínico.

We present a case of subacute extensive thrombosis of the superior mesenteric vein, the venous branches of the jejunal vein, the portal vein at the hilum and its intrahepatic branches, with complete recanalization of the blood flow in the affected vessels without thrombolytic treatment. We provide a detailed description of the clinical and etiological investigations and outcome.

[Acute pancreatitis and malabsorption with tetany secondary to Crohn's disease with duodenal involvement]. / Pancreatitis aguda y malabsorción con tetania secundarias a enfermedad de Crohn con afectación duodenal.

Involvement of the duodenum in Crohn's disease is uncommon, and the pathomechanism of the associated acute pancreatitis remains controversial. We describe a case of Crohn's disease with duodenal involvement associated with hyperamylasemia and malabsorption showing a favorable response to steroid treatment.