New telescope will hunt sources of gravitational waves

A brand new telescope will be the first to search for collisions of black holes and neutron stars in an effort to find sources of gravitational waves.

gravitational wavesthe ripples in spacetime caused by the most energetic collisions known universewere first detected in 2015 by the Laser interferometer Observatory of gravitational waves (LIGO). So far, tracking the sources of these waves has been difficult.

Scientists liken gravitational wave detections to detecting the vibrations of a road surface when a truck has passed, but without being able to actually see the truck. It is almost impossible to know where to look with optical telescopes to search for the sources of these vibrations in the vast universe. The new telescope, called the Gravitational-wave Optical Transient Observer (GOTO), aims to change that.

“There are fleets of telescopes around the world available to look skyward when gravitational waves are detected to find out more about the source,” said Professor Danny Steeghs, head of the astronomy department at the University of Warwick in the UK. and principal investigator of GOTO, said in a statement (opens in a new tab). “But since gravitational wave detectors aren’t able to determine where the ripples are coming from, these telescopes don’t know where to look.”

Related: How a future gravitational wave detector in space will tell more about the universe

Working closely with LIGO and other gravitational wave observatories such as the European Gravitational Wave Observatory, GOTO will scan the entire sky from locations in the northern and southern hemispheres every few days.

Using sophisticated algorithms, the telescope’s computer will analyze the images to look for sudden and intense brightenings in certain parts of the electromagnetic spectrum. Such brightenings could be triggered by collisions of the most massive objects in the universe, black holes and neutron stars. Neutron stars are remnants of supernova explosions, in which giant stars die. Explosions leave behind extremely dense remnants that may be only a few kilometers wide but pack more mass than the whole Sun.

Although extremely energetic, the explosions produced by the collisions of these cosmic behemoths are also extremely fleeting, making the search process difficult following the detection of gravitational waves.

By pairing the detection of gravitational ripples with GOTO’s rapidly processed images, astronomers would know where to point other, more powerful telescopes to study cataclysmic events in more detail.

“[GOTO] was always envisioned to be … arrays of wide-field optical telescopes in at least two sites so that these could patrol and search the optical sky regularly and quickly,” Steeghs said.

“This will allow GOTO to provide that much-needed link, to give the targets that the largest telescopes can point to.”

GOTO was developed by a team of researchers from Australian and British universities. The first network, located at an observatory in La Palma, in the Canary Islands, off the coast of North Africa, was recently tested. The robotic observatory consists of 16 separate 16-inch (40 centimeter) telescopes grouped into two arrays, which share 800 million pixels of resolution between them, the researchers said in the statement. An identical network will soon be deployed at the Australian observatory in Siding Spring near Sydney.

The telescope must be ready for The next LIGO observation campaign, which is expected to begin next year. Since the first gravitational wave detections in 2015, LIGO engineers have improved the instrument’s sensitivity and is now expected to detect gravitational waves from neutron star mergers as far away as 522 million to 620 million. Light years From land. Larger and more violent events, such as black hole collisions and mergers, should be visible to LIGO at even greater distances.

If astronomers can locate the sources of these gravitational wave signals, they could characterize the sources, measure their distances and study their evolution, the researchers said.

“The hope is to catch the event quickly and then track it as it fades, and also to raise an alert to other larger telescopes so they can all collect more of information and that we can build a really detailed picture of these astronomical phenomena,” Steeghs said. said. “It’s a really dynamic and exciting time. In astronomy, we’re used to studying events that date back millions of years and go nowhere – it’s a fast-paced and very different way of working where every minute account.”

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