Category Astronomy/Space

Unusual galaxy set to prompt rethink on how structures in the universe form. Astronomers have captured an image of a super-rare type of galaxy – described as a “cosmic ring of fire” – as it existed 11 billion years ago.

The galaxy, which has roughly the mass of the Milky Way, is circular with a hole in the middle, rather like a titanic doughnut. Its discovery, announced in the journal Nature Astronomy, is set to shake up theories about the earliest formation of galactic structures and how they evolve.

“It is a very curious object that we’ve never seen before,” said lead researcher Dr Tiantian Yuan, from Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimens...

An extraordinary asteroid with comet-like features has researchers puzzled. We often think of asteroids and comets as distinct types of small bodies, but astronomers have discovered an increasing number of “crossovers.” These objects initially appear to be asteroids, and later develop activity, such as tails, that are typical of comets.

Now, the University of Hawai’i Asteroid Terrestrial-impact Last Alert System (ATLAS) has discovered the first known Jupiter Trojan asteroid to have sprouted a comet-like tail. ATLAS is a NASA-funded project using wide-field telescopes to rapidly scan the sky for asteroids that might pose an impact threat to Earth...

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) found quasi-periodic flickers in millimeter-waves from the center of the Milky Way, Sagittarius (Sgr) A*. The team interpreted these blinks to be due to the rotation of radio spots circling the supermassive black hole with an orbit radius smaller than that of Mercury. This is an interesting clue to investigate space-time with extreme gravity.

“It has been known that Sgr A* sometimes flares up in millimeter wavelength,” tells Yuhei Iwata, the lead author of the paper published in the Astrophysical Journal Letters and a graduate student at Keio University, Japan...

The twist marks the spot. Observations made with the European Southern Observatory’s Very Large Telescope (ESO’s VLT) have revealed the telltale signs of a star system being born...