Using red giants to estimate the speed of the universe expansion

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An article being published in “The Astrophysical Journal” reports a new attempt to calculate the speed of the universe expansion, this time using red giant stars as a reference. A team of researchers coordinated by Carnegie Institution for Science and University of Chicago and led by astronomer Wendy Freedman used observations made with the Hubble space telescope to perform that calculation. The result has a probability peak at 69.8 km/s per megaparsec, between the values ​​calculated using the two methods that provided discrepant values.

An explanation for the scarce presence of gold and other rare elements on the Moon

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An article published in the journal “Nature” offers a possible explanation of the remarkable difference in the presence of some chemical elements on the Earth and on the Moon still accepting the theory of their common origin following an impact with the primordial Earth. A team of researchers carried out a series of simulations of the impacts that could have happened on the Moon during the first phase of its history, concluding that the retention of the elements classified as highly siderophilous began 4.35 billion years ago, at the time when most of the magma that covered the lunar surface solidified.

Possible moons in formation around the exoplanet PDS 70 c

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An article published in the journal “The Astrophysical Journal Letters” reports the observation of what is interpreted as a circumplanetary disk in the system of the young star PDS 70. A team of researchers led by Andrea Isella of Rice University in Houston, Texas, used the ALMA radio telescope to detect the emissions of that disk that surrounds the exoplanet PDS 70 c and according to the astronomers is of the type that controls the formation of planets and of a system of moons such as those around the planet Jupiter.

The Spektr-RG space telescope blasting off atop a Proton rocket (Image courtesy Roscosmos)

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A little more than two hours ago, the Spektr-RG space telescope was launched on a Proton rocket from the Baikonur Cosmodrome, Kazakhstan. After about two hours it separated from the rocket’s upper stage to head towards the L2 Lagrangian point, about 1.5 million kilometers from Earth.

The Spektr-RG (Spektr-Roentgen Gamma, SRG) space telescope is a project born from a collaboration of the Russian Roscosmos and German DLR space agencies for the observation of the X-ray sky. This type of astronomy got a bit crippled by the very premature end of the Japanese Hitomi mission while ESA’s XMM-Newton and NASA’s Chandra space telescopes are still active but these are missions that started twenty years ago.

Galaxy NGC 3147 (Image ESA/Hubble & NASA, A. Riess et al.)

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An article published in the journal “Monthly Notices of the Royal Astronomical Society: Letters” reports a study on a supermassive black hole surrounded by a disk of materials that revealed unexpected features. A team of researchers led by Stefano Bianchi, of the University of Roma Tre, Italy, used the Hubble Space Telescope to observe the nucleus of the galaxy NGC 3147 discovering a small and soft disk, a reduced version of the large disks typical of active galactic nuclei, a structure that shouldn’t exist. The discovery represents a new opportunity to test some relativistic effects but could force astronomers to review certain models on active galactic nuclei.