A star with unusual changes in brightness was discovered the Kepler Mission Planet Hunters.
- Published on Thursday, 12 January 2017 14:40
In section 6. Interstellar and circumstellar matter
Anatomy of the internal bow shocks in the IRAS 04166+2706 protostellar jet
Highly-collimated jets and wide-angle outflows are two related components of the mass-ejection activity that are associated with stellar birth. The authors use the ALMA interferometer to study the relation between the jet and the outflow in the IRAS 04166+2706 protostar, which drives a molecular jet that contains multiple emission peaks symmetrically located from the central source, as well as a wide-angle outflow consisting of two conical shells. They find that the emission peaks in the IRAS 04166+2706 jet likely represent internal bow shocks where material is being ejected laterally away from the jet axis. While the linear momentum of the ejected gas is dominated by the component in the jet direction, the sideways component is not negligible, and could potentially affect the distribution of gas in the surrounding outflow and core.
- Published on Thursday, 12 January 2017 14:24
In section 7. Stellar structure and evolution
The 2008 outburst in the young stellar system Z CMa. III. Multi-epoch high-angular resolution images and spectra of the components in near-infrared
Z CMa is a complex pre-main sequence binary with a current separation of 110 mas, known to consist of a FU Orionis star (SE component) and an embedded Herbig Be star (NW component). This paper presents a wealth of new observations, both imaging and spectroscopic, of each component of the Z CMa system during its most recent 2008-2009 outburst (as well as an extra observation once the system was back in its quiescent state). The authors confirm that the NW star dominates the system flux over the 1.1-3.8 mum range and is responsible for the photometric outburst. From extracted medium-resolution (R~2000-4000) near-infrared (1.1-2.4 mum) spectra of the individual components, the authors show that the SE component has a spectrum typical of FU Orionis objects, and that the NW component spectrum is characteristic of embedded out-bursting protostars and EX Or objects. The blueing of the continuum of the NW component along with the absolute flux and color-variation of the system during the outburst suggests that the outburst was caused by a complex interplay between (a) a variation of the extinction in the line of sight of the NW component, and (b) the emission of shocked regions close to the NW component.
Researchers find that chimpanzees are more likely to reproduce with mates whose genetic makeup most differs from their own. Many animals avoid breeding with parents, siblings and other close relatives, researchers say. But chimps are unusual in that even among virtual strangers they can tell genetically similar mates from more distant ones. Chimps are able to distinguish degrees of genetic similarity among unfamiliar mates many steps removed from them in their family tree. Evolutionary Biology news from Science Daily
One branch on the tree of life is heavier as a team of scientists has determined what a bizarre group of extinct cone-shaped animals actually are. Known as hyoliths, these marine creatures evolved over 530 million years ago and are among the first known to have external skeletons. Long believed to be molluscs, a new study shows a stronger relationship to brachiopods — a group with a rich fossil record though few species living today. Evolutionary Biology news from Science Daily
A newly discovered group of microbes provide new insights as to how complex cellular life emerged. The study provides new details of how, billions of years ago, complex cell types that comprise plants, fungi, but also animals and humans, gradually evolved from simpler microbial ancestors. Evolutionary Biology news from Science Daily
Scientists have performed the first all-atom molecular dynamics simulations of Cas9-catalyzed DNA cleavage in action. The simulations shed light on the process of Cas9 genome editing and helped resolve controversies about specific aspects of the cutting.
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Predicting how species will respond to climate change is a critical part of efforts to prevent widespread climate-driven extinction, or to predict its consequences for ecosystems, say scientists. Evolutionary Biology news from Science Daily
What could be learnt about the world if you could read the news from over 100 local newspapers for a period of 150 years? This is what a team of Artificial Intelligence (AI) researchers from the University of Bristol have done, together with a social scientist and a historian, who had access to 150 years of British regional newspapers.
The patterns that emerged from the automated analysis of 35 million articles ranged from the detection of major events, to the subtle variations in gender bias across the decades. The study has investigated transitions such as the uptake of new technologies and even new political ideas, in a new way that is more like genomic studies than traditional historical investigation.
The team of academics, led by Professor Nello Cristianini, collaborated closely with the company findmypast, who is digitising historical newspapers from the British Library as part of their British Newspaper Archive project.
The main focus of the study was to establish if major historical and cultural changes could be detected from the subtle statistical footprints left in the collective content of local newspapers. How many women were mentioned? In which year did electricity start being mentioned more than steam? Crucially, this work goes well beyond counting words, and deploys AI methods to identify people and their gender, or locations and their position on the map.
The landmark study, part of the University of Bristol’s ThinkBIG project, collected a huge amount of regional newspapers from the UK, including geographical and time-based information that is not available in other textual data such as books. Over 35 million articles and 28.6 billion words, from the British Library’s newspaper collections, representing 14 per cent of all British regional outlets from 1800 to 1950, were used for the study.
Source / Read more: alphagalileo