Cosmology

The First Stars

The First Stars

  The first stars in the Universe are believed to have formed only a few hundred million years after the Big Bang, about 13.7 billion years ago. They heated and ionized the pristine intergalactic medium, and their supernova explosions enriched the primordial gas with the first heavy elements (the Universe was born with only hydrogen [continue reading]

Infant Galaxies Merging Near ‘Cosmic Dawn’

Infant Galaxies Merging Near ‘Cosmic Dawn’

  Astronomers using the combined power of the Atacama Large Millimeter/submillimeter Array (ALMA) telescope and NASA’s Hubble Space Telescope have discovered a far-flung trio of primitive galaxies nestled inside an enormous blob of primordial gas nearly 13 billion light-years from Earth. This composite image reveals the structure of Himiko, an object representing the merger of [continue reading]

Small Star Pulled Apart by Medium-Sized Black Hole

Small Star Pulled Apart by Medium-Sized Black Hole

  On the edge of the nearby galaxy Messier 86, astronomers have observed a strange X-ray flash. This flash has almost certainly been caused by a rare cosmic accident in which a small star is pulled apart by a medium-sized black hole. The discovery may provide the missing evidence for the existence of medium-sized black [continue reading]

Carbon Worlds Likely Bone-Dry and Lifeless

Carbon Worlds Likely Bone-Dry and Lifeless

  Planets rich in carbon, including so-called diamond planets, may lack oceans, according to NASA-funded theoretical research.  This artist’s concept illustrates the fate of two different planets: the one on the left is similar to Earth, made up largely of silicate-based rocks with oceans coating its surface. The one on the right is rich in [continue reading]

The Deepest Probe of the Universe Ever

The Deepest Probe of the Universe Ever

  NASA’s Great Observatories are teaming up to look deeper into the Universe than ever before. With a boost from natural “zoom lenses” found in space, they should be able to uncover galaxies that are as much as 100 times fainter than what the Hubble, Spitzer, and Chandra space telescopes can typically see. Abell 2744 [continue reading]

Most Distant Galaxy is Forming Stars Extremely Fast

Most Distant Galaxy is Forming Stars Extremely Fast

  University of Texas at Austin astronomer Steven Finkelstein has led a team that has discovered and measured the distance to the most distant galaxy ever found. The galaxy is seen as it was at a time just 700 million years after the Big Bang. An artist’s rendition of the newly discovered most distant galaxy [continue reading]