Posted on

The Milky Way's Disk is Warped. Is That Because our Dark Matter Halo is Tilted?

Astronomers have measured the Milky Way’s shape and found that the disk is warped and not a flat spiral like many of the galaxies we see in the Universe. It was assumed a collision with another galaxy in the ancient past caused this warping. Observations have shown that the galactic stellar halo is tilted concerning the galactic plane, and a new theory proposes that the dark matter halo is tilted, too. This tilt might be torquing the galaxy, causing the warp that astronomers have observed.

Posted on

A New Observatory Will Spot Core-Collapse Supernovae Before They Explode

Although we haven’t had a supernova explode nearby in a few hundred years, it’s just a matter of time before it happens. Astronomers want to be ready. The Jiangmen Underground Neutrino Observatory is being built in China and should be gathering its first data by the end of 2023. If all goes well, it can detect a burst of neutrinos coming from a core-collapse supernova before we can see the flash of radiation. As the star is imploding, energy piles up inside the star, but the neutrinos can freely escape, arriving seconds earlier than the radiation. It’ll have a range of 3,000 light-years for pre-supernova neutrino detections and 1.2 million light-years for post-supernova detection.

Posted on

If Neutron Stars Have Mountains, They Should Generate Gravitational Waves

Astronomers have discovered the gravitational waves released by colliding black holes, neutron stars, and even the background waves from merging supermassive black holes. A new paper proposes that advanced gravitational wave observatories might be able to detect the presence of “mountains” on spinning neutron stars. Although they’re incredibly dense, neutron stars have layers, and as they cool, their solid crusts might deform into regions farther from the central core. This would create a wobble that would release gravitational waves.

Posted on

Do The Gaps in Protoplanetary Disks Really Indicate Newly Forming Planets?

Modern instruments like ALMA have revealed newly forming stars surrounded by accretion disks. These images are so sensitive you can even see the gaps in the disk where new planets form, right? Maybe not. According to a new paper, systems with many newly forming planets are inherently unstable, so they can’t all indicate new worlds. Some gaps and rings around the stars might just indicate collections of pebbles that can never accrete into actual planets. The challenge will be to figure out which is which.

Posted on

JWST Might Have Imaged a Hycean World for the First Time, With a Hydrogen-Rich Atmosphere and a Deep Planet-Wide Water Ocean

Astronomers have directed JWST to examine the atmosphere of an exoplanet called K2-18 b, which orbits a cool dwarf star about 120 light-years from Earth. The planet is 8.6 times as massive as Earth, and the observations have revealed methane and carbon dioxide in its atmosphere. This opens up the intriguing possibility that this exoplanet is an example of a theorized “hycean world,” a planet with a hydrogen-rich atmosphere and a water ocean covering its surface that extends deeper than anything we have on Earth.

Posted on

The Closest Black Holes to Earth are Probably Hidden in This Nearby Star Cluster

The Hyades cluster is the closest open star cluster to Earth, located at a distance of about 150 light-years. Although black holes haven’t been directly seen in the cluster, it’s an excellent place to search for them because the largest stars would have detonated as supernovae and collapsed in neutron stars and black holes. Astronomers have simulated the motions of stars in the cluster with black holes lurking around and then compared them to the motions of the actual stars. They only matched with the presence of black holes near the center of the cluster.

Posted on

The Case for a Small Universe

Astronomers don’t know if the Universe is finite or infinite. Whatever the case, it’s larger than the Observable Universe, which measures 93 billion light-years across. A new paper proposes that the actual Universe is comparatively tiny, not much bigger than its observed size – just a few orders of magnitude larger. A smaller Universe solves some problems with other theories of cosmology, including inflation and the amount of dark energy in the Universe.

Posted on

Should the Next Big Observatories Be Built on the Moon?

As the next round of giant observatories nears completion, astronomers are starting to ponder what comes next. One exciting location to consider is the Moon. There’s no atmosphere on the Moon, so a lunar telescope would act like a space telescope. Still, solid ground, lower gravity, and potentially human astronauts are available to do maintenance and make upgrades. A new paper reviews different kinds of telescopes that could be built on the Moon and their unique advantages over Earth- or space-based instruments.

Posted on

The Most Distant Galactic Field Lines Ever Seen

Galaxies are surrounded by magnetic field lines, spanning tens of thousands of light-years. These magnetic fields have previously been measured surrounding only the closest galaxies. Still, astronomers have made the map of a galaxy seen just a few billion years after the Big Bang. Astronomers discovered with ALMA, searching dust grains in the galaxy that align with the nearby magnetic fields. The light they emit becomes polarized, which can then be turned into magnetic field maps.