Enlarge / A jet of particles moving at nearly light-speed emerges from a massive star in this artist’s concept of the BOAT. (credit: NASA's Goddard Space Flight Center Conceptual Image Lab)

Scientists have been all aflutter since several space-based detectors picked up a powerful gamma-ray burst (GRB) in October 2022—a burst so energetic that astronomers nicknamed it the BOAT (Brightest Of All Time). Now an international team of astronomers has analyzed an unusual energy peak detected by NASA's Fermi Gamma-ray Space Telescope and concluded that it was an emission spectra, according to a new paper published in the journal Science. Per the authors, it's the first high-confidence emission line ever seen in 50 years of studying GRBs.

As reported previously, gamma-ray bursts are extremely high-energy explosions in distant galaxies lasting between mere milliseconds to several hours. There are two classes of gamma-ray bursts. Most (70 percent) are long bursts lasting more than two seconds, often with a bright afterglow. These are usually linked to galaxies with rapid star formation. Astronomers think that long bursts are tied to the deaths of massive stars collapsing to form a neutron star or black hole (or, alternatively, a newly formed magnetar). The baby black hole would produce jets of highly energetic particles moving near the speed of light, powerful enough to pierce through the remains of the progenitor star, emitting X-rays and gamma rays.

Those gamma-ray bursts lasting less than two seconds (about 30 percent) are deemed short bursts, usually emitting from regions with very little star formation. Astronomers think these gamma-ray bursts are the result of mergers between two neutron stars, or a neutron star merging with a black hole, comprising a "kilonova." That hypothesis was confirmed in 2017 when the LIGO collaboration picked up the gravitational wave signal of two neutron stars merging, accompanied by the powerful gamma-ray bursts associated with a kilonova.

Enlarge / NASA's James Webb Space Telescope reveals the Rho Ophiuchi cloud complex, the closest star-forming region to Earth.

In a feat of galactic archeology, astronomers are using ever more detailed information to trace the origin of our galaxy—and to learn about how other galaxies formed in the early stages of the Universe. Using powerful space telescopes like Gaia and James Webb, astronomers are able to peer back in time and look at some of the oldest stars and galaxies. Between Gaia’s data on the position and movements of stars within our Milky Way and Webb’s observations of early galaxies that formed when the Universe was still young, astronomers are learning how galaxies come together and have made surprising discoveries that suggest the early Universe was busier and brighter than anyone previously imagined.

The Milky Way’s earliest pieces

In a recent paper, researchers using the Gaia space telescope identified two streams of stars, named Shakti and Shiva, each of which contains a total mass of around 10 million Suns and which are thought to have merged into the Milky Way around 12 billion years ago.

These streams were present even before the Milky Way had features like a disk or its spiral arms, and researchers think they could be some of the earliest building blocks of the galaxy as it developed.

Enlarge / Hubble Space Telescope above Earth, photographed during STS-125, Servicing Mission 4, May 2009. (credit: NASA)

The venerable Hubble Space Telescope is running out of gyroscopes, and when none are left, the instrument will cease to conduct meaningful science.

To preserve the telescope, which has been operating in space for nearly three and a half decades, NASA announced Tuesday that it will reduce the Hubble's operations such that it will function on just a single gyroscope. This will limit some scientific operations, and it will take longer to point the telescope to new objects and lock onto them.

But in a conference call with space reporters, Hubble officials stressed that the beloved scientific instrument is not going anywhere any time soon.