Astronomy / Astrophysics

A section of the three-dimensional map of the galaxies of the Sloan Digital Sky Survey used for the analysis

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An article published in the journal “Physical Review Letters” reports a new estimate of the expansion of the universe based on the large cosmic structures formed by galaxies. A team of researchers led by Dr. Seshadri Nadathur of the British University of Portsmouth’s Institute of Cosmology and Gravitation (ICG) used data about over one million galaxies and quasars collected over a decade by the Sloan Digital Sky Survey to create an analysis that provided a measure of the effects of the mysterious dark energy that’s accelerating the expansion of the universe. Adding a new method of its calculation doesn’t necessarily lead to the right value, but can help understand why other methods provide incompatible results and where we might need to expand our knowledge of physics to obtain the right value.

Artistic representation of an extreme horizontal branch star with a giant star spot

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An article published in the journal “Nature Astronomy” reports a study on stars of a particular type since they’re much smaller than the Sun but much hotter and therefore blue. A team of researchers led by Yazan Al Momany of the Italian National Institute of Astrophysics, Padua, used various instruments on ESO’s Very Large Telescope (VLT) and NTT (New Technology Telescope) in Chile to study stars of that type discovering the equivalent of sunspots but even three thousand times larger in size. In some of these spots, flares have been observed that are millions of times more intense than the Sun’s which indicate the presence of very intense magnetic fields.

A diagram of the evolution of the interstellar asteroid 'Oumuamua's size and shape

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An article accepted for publication in the “Astrophysical Journal Letters” reports a study on the interstellar asteroid 1I/2017 U1 / ‘Oumuamua that offers an explanation for its strange properties. Professor Gregory Laughlin of the University of Yale and Dr. Darryl Seligman of the University of Chicago examined the data collected during the various observations of ‘Oumuamua concluding that it could contain a significant percentage of hydrogen ice and could have originated in the heart of a molecular cloud.

Artist's concept of a super-Earth with its star behind it (Image courtesy M. Weiss/CfA)

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An article accepted for publication in the journal “Astronomy & Astrophysics” reports the discovery of a super-Earth in the system of HD 164922, a star that’s slightly smaller and slightly less massive than the Sun. A team of researchers led by Serena Benatti of the Italian National Institute for Astrophysics, Palermo, used the HARPS-N spectrograph installed on the Galileo Telescope, on the Canary Islands, to collect the data which, together with others previously collected with other instruments, allowed to discover the exoplanet designated as HD 164922d. The discoveries of exoplanets are increasingly made thanks to software that performs an automatic analysis of data collected by various telescopes, but in this case it’s the prize for the tenacity of astronomers who put together the data of years of observations conducted with various instruments.

An FRB's journey to Earth (Image courtesy ICRAR)

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An article published in the journal “Nature” reports a measurement of the amount of the so-called baryonic matter, ordinary matter, in the universe analyzing the characteristics of fast radio bursts (FRBs). A team of researchers led by Professor Jean-Pierre Macquart from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), used detections carried out using the ASKAP radio telescope, which allowed to determine the position of the FRBs in the galaxies that host them with considerable precision. By analyzing their characteristics it was possible to determine the density of matter between their point of origin and the Earth.