NASA’s speedy, sun-like spies are consumed bite by bite

Scientists using NASANeil Gehrels Swift’s Observatory identified a Black hole In a distant galaxy it appears to be repeatedly consuming parts of a sun-like star. This groundbreaking discovery was made possible thanks to a new method of analyzing data from the observatory’s X-ray Telescope (XRT).

Using NASA’s Neil Girls Swift Observatory, which launched in 2004, scientists discovered a black hole in a distant galaxy repeatedly gnawing away at a sun-like star. This object heralds a new era of Swift science made possible by a new method of analyzing data from the satellite’s X-ray Telescope (XRT).

“SWIFT’s hardware, software and the skills of its international team have enabled it to adapt to new areas of astrophysics throughout its life,” said Phil Evans, an astrophysicist at the University of Leicester in the UK and a long-time member of the SWIFT team. Neil Girls, the expedition’s namesake, oversaw and encouraged many of those transformations. Now, with this new ability, it’s delivering even more cool science.

Evans led a study of the unlucky star and its hungry black hole, collectively called Swift J023017.0+283603 (or Swift J0230 for short), which was published on September 7 in Nature astronomy.

Watch to learn how an update allowed NASA’s Neil Gehrels Swift Observatory to capture a massive black hole in a distant galaxy repeatedly feeding on a rotating star. Source: NASA Goddard Space Flight Center

Tidal disturbance events and their changes

When a star approaches a massive black hole, gravitational forces create intense tides that split the star into a stream of gas. The leading edge oscillates around the black hole, while the trailing edge escapes the system. These destructive events are called tidal disturbance events. Astronomers see them as flares of multi-wavelength light that arise when debris collides with a disk of material already orbiting the black hole.

Recently, astronomers have investigated variations of this phenomenon, which they call partial or recurrent tidal perturbations.

During these events, every time an orbiting star passes close to a black hole, the star bulges outward and sheds material, but survives. The process is repeated until the star loses too much gas and finally disintegrates. The properties of an individual star system and black holes determine the type of emissions that scientists observe, creating a wide range of behaviors to classify.

Previous examples include an explosion that occurs every 114 days, likely caused by a giant star orbiting a black hole 78 million times the mass of the Sun. It occurs again every nine hours around a black hole with a mass of 400,000 times the mass of the Sun, and is likely caused by a stellar cinder orbiting around it called White dwarf.

Swift J0230 occurred more than 500 million light-years away in a galaxy called 2MASX J02301709+2836050, captured here by the Pan-STARRS telescope in Hawaii. Image source: Niels Bohr Institute/Daniele Malesani

Swift J0230: a new recurrent disorder

On June 22, 2022, the XRT camera captured an image of Swift J0230 for the first time. It was illuminated in a galaxy about 500 million light-years away in the northern constellation Triangle. Swift’s XRT observed nine additional seizures from the same location about every few weeks.

Evans and his team suggest that Swift J0230 is a recurring tidal disturbance of a Sun-like star orbiting a black hole more than 200,000 times the mass of the Sun. They estimate that the star loses about three Earth masses of material each pass. This system provides a bridge between other types of suspected recurring disturbances, and allows scientists to model how interactions between different types of stars and sizes of black holes affect what we observe.

“We looked and looked for the brightness of the event in the data collected by the Swift ultraviolet/optical telescope,” said Alice Brayfield, a research fellow at the Mullard Space Science Laboratory (MSSL) at University College London, who has worked on the instrument since before the satellite. Launched. “But there was no sign of it. The galaxy was completely fluctuating in the X-rays. That helped rule out some other possible causes.”

Illustration of NASA’s Swift satellite. Credit: NASA

The discovery of Swift J0230 was made possible by a new automated search for XRT observations, developed by Evans, called Swift X-ray Transient Detector.

After the device observes part of the sky, the data is transmitted to Earth, and the program compares it with previous XRT snapshots of the same place. If that part of the sky changes in X-rays, scientists receive an alert. In the case of Swift J0230, Evans and his colleagues were able to quickly coordinate additional observations of the region.

SWIFT was originally designed to study gamma-ray bursts, the most powerful explosions in the universe. However, since the satellite’s launch, scientists have realized its potential to study a whole range of celestial bodies, such as tidal disturbances and comets.

S said “SWIFT J0230 was discovered only about two months after Phil launched its program,” said Bradley Sinko, the mission’s principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It bodes well for the detector’s ability to identify other transient events and for SWIFT’s future exploration of new areas of science.”

Reference: “Quasi-periodic monthly outbursts resulting from recurring stellar disturbance by a massive black hole” by PA Evans, CJ Nixon, S. Campana, P. Charalampopoulos, DA Perley, AA Breeveld, KL Page, SR Oates, RAJ Eyles-Ferris, D. P. Malesani, L. Izzo, M. R. Goad, P. T. O’Brien, J. P. Osborne, P. Sparovati, September 7, 2023, Nature astronomy.
doi: 10.1038/s41550-023-02073-j

Goddard manages the SWIFT mission in cooperation with Penn State, Los Alamos National Laboratory in New Mexico, and Northrop Grumman Space Systems in Dallas, Virginia. Other partners include Leicester, MSSL, the Brera Observatory in Italy, and the Italian Space Agency.