Category Astronomy/Space

Andromeda galaxy

CU Boulder researchers have discovered a mechanism that explains the persistence of asymmetrical stellar clusters surrounding supermassive black holes in some galaxies and suggests that during post-galactic merger periods, orbiting stars could be flung into the black hole and destroyed at a rate of one per year.

A supermassive black hole’s gravity creates a nuclear star cluster surrounding it, which gravitational physics would expect to be spherically symmetric. However, several galaxies – including nearby Andromeda – have been observed with an asymmetrical star cluster that takes the form of a disk instead. Eccentric disks are suspected to be formed in the wake of a recent merger between two gas-rich galaxies.

Within the disk, each star follows an elliptical orbit that re...

Lead author Fabian Schneider, a Hintze Research Fellow in the University of Oxford’s Department of Physics, said: “We were astonished when we realised that 30 Doradus has formed many more massive stars than expected.”

Astronomers have revealed an ‘astonishing’ overabundance of massive stars in a neighboring galaxy. The discovery, made in a gigantic star-forming region of the Large Magellanic Cloud galaxy, has ‘far-reaching’ consequences for our understanding of how stars transformed the pristine Universe into the one we live in today. As part of the VLT-FLAMES Tarantula Survey (VFTS), the team used ESO’s Very Large Telescope to observe nearly 1,000 massive stars in 30 Doradus, a gigantic stellar nursery also known as the Tarantula Nebula...

Galaxy-scale outflow driven by the central black hole. Credit: ESA

New theory predicts origins of molecules in destructive cosmic outflows. The existence of large numbers of molecules in winds powered by supermassive black holes at the centers of galaxies has puzzled astronomers since they were discovered more than a decade ago. Molecules trace the coldest parts of space, and black holes are the most energetic phenomena in the universe, so finding molecules in black hole winds was like discovering ice in a furnace.

Astronomers questioned how anything could survive the heat of the energetic outflows, but a new theory from researchers in Northwestern University’s Center for Interdisciplinary Research and Exploration in Astrophysics (CIERA) predicts that these molecules are not survivors at a...

First stars of the Milky Way. Credit: Gabriel Pérez, SMM (IAC)

Researchers at the IAC have identified a star which is a key to the formation of the first chemical elements in the Galaxy. The study presents the discovery of one of the stars with the least content of “metals” (heavy elements) known. The star is 7,500 light years from Earth, in the halo of the Milky Way, and is along the line of sight to the constellation of the Lynx. The star is still on the Main Sequence, the stage at which most stars spend the major part of their lives. The source of energy of these stars is, as always, the fusión of hydrogen in their cores, and their surface temperaturas and luminosities are almost constant with time. Another of its properties is its low mass, around 0...