A new telescope detects Two ‘dead suns’ in an epic collision
The collisions of neutron stars are critical to our understanding of the Universe.
They are thought to have created heavy metals that formed stars and planets like our own billions of years ago.
Light from the crashes is only visible for a few nights, so the telescope must race to locate them.
Astronomers observed one of these collisions in 2017 but largely came across it by luck.
The British-built Gravitational Wave Optical Transient Observer (GOTO), located above the clouds on the volcanic Spanish island of La Palma, will now systematically hunt for them.
"When an excellent detection comes along, it's all hands on deck to make the most of it," Prof Danny Steeghs of Warwick University told me on La Palma.
"Speed is of the essence. We are looking for something very short-lived - there's not much time before they fade".
Neutron stars are so heavy that a small teaspoon of their material weighs four billion tonnes.
The telescope allows astronomers to crack one open to see what is inside effectively.
So that it can get a clear view of the sky, the telescope is situated on a mountain peak, home to a dozen instruments of all shapes and sizes, each studying different phenomena.
When its twin domes open, they reveal two jet-black batteries of eight cylindrical telescopes bolted together - structures that look more like menacing rocket launchers.
Each battery covers every patch of sky above it by rapidly rotating vertically and horizontally
A neutron star is a dead sun that has collapsed under its immense weight, crushing the atoms that once made it shine. They have such strong gravity that they are drawn to each other. Eventually, they crash together and merge.
When that happens, they create a flash of light and a powerful shockwave ripples across the Universe. It makes everything in the Universe wobble, including, imperceptibly, the atoms inside each one of us.
The shockwave called a gravitational wave, distorts space. When it is detected on Earth, the new telescope scrambles into action to find the exact location of the flash.
The operators aim to locate it within hours or even minutes of the gravitational wave detection. They take photographs of the sky and digitally remove the stars, planets and galaxies that were there the previous night. Any speck of light that wasn't there before may be the colliding neutron stars.
This usually takes days and weeks, but now it must be done in real-time. It's a big task, done using computer software.
"You would think these explosions are very energetic, very luminous; it should be easy," said astrophysics professor Dr Joe Lyman.
"But we must search through a hundred million stars for the one object we are interested in.
"We must do this rapidly because the object will disappear within two days."
The team worked with other astronomers to study the collision in greater detail.
Once they pinpoint the collision, they turn to larger, more powerful telescopes worldwide. These probe the crash in much greater detail and at different wavelengths.
This process is "telling us about physics at the extreme," Dr Lyman explains.
The mountain peak brings the astronomers a little bit closer to the stars. With the telescope, they have a new way to peer into the cosmos, says GOTO's instrumentation scientist, Dr Kendall Ackley.
Traditional astronomy was about being lucky, she says. "Now, we're not hoping for discoveries anymore. Instead, we're being told where to find them and getting to uncover, piece-by-piece, what lies out there in the Universe."
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