Category Astronomy/Space

Taking the Temperature of Dark Matter

Astronomical image
This image from the Hubble Space Telescope shows lensing of distant galaxies by gravity. UC Davis astronomers are using this phenomenon to learn more about the properties of dark matter.

Warm, cold, just right? Physicists at the University of California, Davis are taking the temperature of dark matter, the mysterious substance that makes up about a quarter of our universe.

We have very little idea of what dark matter is and physicists have yet to detect a dark matter particle. But we do know that the gravity of clumps of dark matter can distort light from distant objects. Chris Fassnacht, a physics professor at UC Davis and colleagues are using this distortion, called gravitational lensing, to learn more about the properties of dark matter.

The standard model for dark matter is ...

Read More

When the Milky Way Collided with Dwarf Galaxy Gaia-Enceladus

A snapshot from TESS of part of the southern sky showing the location of ν Indi (blue circle), the plane of the Milky Way (bottom left) and the southern ecliptic pole (top). These snapshots come from data collected in TESS observing sectors 1, 12 and 13.
[less]
© J. T. Mackereth

The dwarf galaxy Gaia-Enceladus collided with the Milky Way probably approximately 11.5 billion years ago. A team of researchers including scientists from the Max Planck Institute for Solar System Research in Germany for the first time used a single star affected by the collision as a clue for dating...

Read More

Astronomers discover class of Strange Objects near our Galaxy’s Enormous Black Hole

Image shows 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.

Astronomers from UCLA’s Galactic Center Orbits Initiative have discovered a new class of bizarre objects at the center of our galaxy, not far from the supermassive black hole called Sagittarius A*. They published their research today in the journal Nature.

“These objects look like gas and behave like stars,” said co-author Andrea Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics and director of the UCLA Galactic Center Group.

The new objects look compact most of the time and stretch out when their orbits bring them closest to the black hole...

Read More

How the Solar System got its ‘Great Divide,’ and why it matters for Life on Earth

An orrery, a type of device once used to track the movements of the planets, sitting above an infrared image of a hypothetical "protoplanetary" disk that may have divided the solar system early in its history.
An orrery, a type of device once used to track the movements of the planets, sitting above an infrared image of a hypothetical “protoplanetary” disk that may have divided the solar system early in its history. (Credit: K. Ebert/Innovative Ideas & Methods)

Scientists, including those from the University of Colorado Boulder, have finally scaled the solar system’s equivalent of the Rocky Mountain range. In a study published in Nature Astronomy, researchers from the United States and Japan unveil the possible origins of our cosmic neighborhood’s “Great Divide.” This well-known schism may have separated the solar system just after the sun first formed.

The phenomenon is a bit like how the Rocky Mountains divide North America into east and west...

Read More