Here’s a hand-wavy attempt: a galaxy is a collection of stars, gas, dust and dark matter all held together by mutual gravity. At the lower end of the scale, some very small galaxies could be ...

Here’s how stars reveal a galaxy’s age—and what powers active cores like quasars and blazars.

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London. Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and ...

Less than 2 billion years after the Big Bang, a galaxy roughly three times the mass of the Milky Way had already stopped forming stars, settled into a bloated shape, and lost something astronomers did ...

Seen from Earth, the giant elliptical galaxy M87 is just a two-dimensional blob, though one that appears perfectly symmetrical and thus a favored target of amateur astronomers. Yet, a new, highly ...

It is as humbling as it is motivating to think about how much we still have to learn about the universe. My collaborators and I have just tackled one of astrophysics’ enduring mysteries: how massive ...

Ohio University astronomers have discovered the largest disk of hot, X-ray emitting gas ever observed in the universe: At 90,000 light years in diameter, it’s about 100,000 times the size of any ...

Orbits of the G objects at the center of our galaxy, with the supermassive black hole indicated with a white cross. Stars, gas and dust are in the background. Credit - Anna Ciurlo, Tuan Do/UCLA ...

According to the prevailing “cold dark matter” theory of the evolution of the universe, every galaxy is surrounded by a halo of dark matter that can only be detected indirectly by observing its ...

Using the James Webb Space Telescope (JWST), an international team of astronomers has observed an elliptical galaxy known as NGC 4486B. Results of the observational campaign, published Dec. 16 on the ...