Tour: NASA Discovers Crash of Extreme Stars in Unexpected Site
(Credit: NASA/CXC/A. Hobart)
[Runtime: 04:00]

With closed-captions (at YouTube)

A fleet of NASA telescopes may have uncovered a collision between two ultradense stars in a tiny galaxy buried in a huge stream of gas. Astronomers have never seen this type of explosive event in an environment like this before — and it may help solve two outstanding cosmic mysteries.

Neutron stars are the cores left behind after a star much heavier than the Sun runs out of fuel, collapses on itself, and then explodes. They are small — only a dozen or so miles across — but have more mass than our Sun. This makes them amazingly dense, and astronomers consider them to be some of the most extreme objects in the universe.

In recent years, astronomers have collected data on collisions, or mergers, of two neutron stars inside of moderately sized or large galaxies. This latest discovery, however, shows that a neutron star collision may take place inside a tiny galaxy.

This tiny galaxy where astronomers found GRB 230906A, which is what astronomers call this event, is embedded in a stream of gas that stretches for some 600,000 light-years.

The unexpected location of GRB 230906A may help unlock not one, but two important questions in astrophysics. The first puzzle that this unprecedented location for a neutron star collision may explain are gamma-ray bursts that appear to have no galaxies associated with them. The other question this result could address is how elements like gold and platinum have been found in stars located at large distances from the centers of galaxies.

Astronomers think the stream where GRB 230906A was found was likely created when a group of galaxies collided hundreds of millions of years ago, stripping gas and dust from the galaxies and leaving it in intergalactic space. This means that GRB 230906A may be the product of a collision within a collision. The galaxy collision triggered a wave of star formation that, over hundreds of millions of years, led to the birth and eventual collision of these neutron stars.

To identify and get the true nature of GRB 230906A, which occurred on September 6th, 2023, astronomers needed several NASA telescopes including the Chandra X-ray Observatory, Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and Hubble Space Telescope.

Fermi discovered the neutron star collision by picking up a distinctive gamma-ray burst, or GRB. After using the InterPlanetary Network to derive a position of the Fermi source, astronomers then needed the sharp vision of Chandra, Swift, and Hubble to more precisely pinpoint the location of the object.

This is a great example of how telescopes working together can make remarkable discoveries, Without Chandra, the researchers couldn’t have tied the burst to any specific source. And once Chandra told them exactly where to look, Hubble’s extraordinary sensitivity revealed the tiny, extremely faint galaxy at that position. By putting all of the pieces together, the team was able to find something never seen before and maybe answer questions that have been open for many years.

Quick Look: NASA Discovers Crash of Extreme Stars in Unexpected Site
(Credit: NASA/CXC/A. Hobart)
[Runtime: 00:46]

With narration (video above with voiceover)

Astronomers have spotted the merger between two neutron stars in a very odd place.

This extreme collision was found in a tiny galaxy embedded in a stream of gas.

Scientists needed NASA’s Chandra, Fermi, Swift, and Hubble to make this discovery.

This result may help answer two different mysteries about stars and intergalactic space.