Category Astronomy/Space

In 2014, astronomers using the NASA/ESA Hubble Space Telescope found that this enormous galaxy cluster contains the mass of a staggering three million billion suns — so it’s little wonder that it has earned the nickname of “El Gordo” (“the Fat One” in Spanish)! Known officially as ACT-CLJ0102-4915, it is the largest, hottest, and brightest X-ray galaxy cluster ever discovered in the distant universe. Credit: ESA/Hubble & NASA, RELICS

In 2014, astronomers using the NASA/ESA Hubble Space Telescope found that this enormous galaxy cluster contains the mass of a staggering three million billion suns – so it’s little wonder that it has earned the nickname of “El Gordo” (“the Fat One” in Spanish)! Known officially as ACT-CLJ0102-4915, it is the largest, hottest, and brightest X-ray galaxy cluster...

Gravitational-wave emission from a collapsing star

Astrophysicists at Goethe University Frankfurt set a new limit for the maximum mass of neutron stars: It cannot exceed 2.16 solar masses. Since their discovery in the 1960s, scientists have sought to answer an important question: How massive can neutron stars actually become? By contrast to black holes, these stars cannot gain in mass arbitrarily; past a certain limit there is no physical force in nature that can counter their enormous gravitational force.

With a radius of about 12 km and a mass that can be twice as large as that of the sun, neutron stars are amongst the densest objects in the Universe, producing gravitational fields comparable to those of black holes. Whilst most neutron stars have a mass of around 1...

This Hubble Space Telescope image of a sparkling jewel box full of stars captures the heart of our Milky Way galaxy. Aging red giant stars coexist with their more plentiful younger cousins, the smaller, white, Sun-like stars, in this crowded region of our galaxy’s ancient central hub, or bulge. Most of the bright blue stars in the image are probably recently formed stars located in the foreground, in the galaxy’s disk. Astronomers studied 10,000 of these Sun-like stars in archival Hubble images over a nine-year period to unearth clues to our galaxy’s evolution. Release type: American Astronomical Society Meeting

A new analysis of about 10,000 normal Sun-like stars in the Milky Way’s bulge reveals that our galaxy’s hub is a dynamic environment of variously aged stars zipping around at diffe...

: N. Giammichele et al. A large oxygen-dominated core from the seismic cartography of a pulsating white dwarf, Nature (2018). DOI: 10.1038/nature25136 Credit: University of Montreal

This week, Nature published an article that could challenge the theory of stellar evolution. “I think that, over the coming months, stellar astrophysicists will have to redo their calculations,” said Gilles Fontaine, a physics professor at Université de Montréal and one of the authors of the article, titled “A large oxygen-dominated core from the seismic cartography of a pulsating white dwarf.”

Its lead author is Noemi Giammichele, who completed her doctorate in 2016 under the joint supervision of Fontaine and his colleague Pierre Bergeron, both of whom co-authored the article along with 6 other researchers...