Black Hole Snack Attack: NASA’s Swift Spies Outshoot the Sun Like a Biting Star

In this artist’s view, a supermassive black hole is pulling a stream of gas from a star that passes very close. NASA’s Swift Observatory has identified a black hole that is consuming a Sun-like star, demonstrating the potential of the observatory’s evolution and new methods of data analysis. Credit: NASA Goddard Flight Center / Chris Smith (USRA/GESTAR)

Scientists, you use NASA‘s Neil Gehrels Swift Observatory, identified the black hole in a distant galaxy that appears to repeatedly contain parts of a Sun-like star. This fundamental discovery was made possible by a new method of analyzing data from the Observatory’s X-ray Telescope (XRT).

Using NASA’s Neil Gehrels Swift Observatory, launched in 2004, scientists have discovered a black hole in a long galaxy piercing a Sun-like star. This heralds a new era of Swift science made possible by a new method of analyzing data from the X-ray Telescope (XRT) satellite.

“Swift’s tools, 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 United Kingdom and a long-time member of the Swift team. “Neil Gehrels, the namesake of this work, oversaw and inspired many of those changes. Now, with this new technology, make science even cooler. “

Evans led a study about the lucky star and its hungry black hole, called Swift J023017.0+283603 (or Swift J0230 for short), which was published on September 7 at Natural Astronomy.

Watch to learn how NASA’s renovation of the Neil Gehrels Swift Observatory has allowed it to catch a supermassive black hole in a distant galaxy repeatedly piercing an orbiting star. Credit: NASA’s Goddard Space Flight Center

Tidal disturbance phenomena and their variations

When a star gets too close to a supermassive black hole, the force of gravity creates massive waves and breaks the star apart into a stream of gas. The leading edge swings around the black hole, and the trailing edge runs through the system. These destructive episodes are called wave disturbances. Astronomers see them as flares of light of many wavelengths created when debris collides with the disk of material already orbiting the black hole.

Recently, astronomers have been investigating the dynamics of this phenomenon, which they call partial or multiple perturbations.

During these events, every time an orbiting star passes close to a black hole, the star ejects and expels matter, but survives. The process repeats until the star loses more gas and eventually breaks up. The characteristics of each star and black hole system determine what type of science output is observed, creating a wide range of behaviors to classify.

Previous examples include outbursts occurring every 114 days, which may be caused by a supermassive star orbiting a black hole 78 million times the size of the Sun. One repeats every nine hours around a black hole 400,000 times the size of the Sun, possibly caused by a rotating stellar cinder called black and white.

Swift J0230 occurs more than 500 million light-years away in a galaxy named 2MASX J02301709+2836050, captured here by the Pan-STARRS telescope in Hawaii. Credit: Neils Bohr Institute/Daniele Malesani

Swift J0230: A New Recurring Disturbance

On June 22, 2022, XRT captured Swift J0230 for the first time. It shines in a galaxy about 500 million light-years from the northern point of Triangulum. The Swift’s XRT has seen nine additional explosions in the same area over the past few weeks.

Evans and his team suggest that Swift J0230 is a repeated disruption 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 per pass. This system provides a bridge between other types of suspected repulsive interference and allows scientists to show how interactions between different types of stars and the size of the black hole affect what we see.

“We searched and searched for a bright event in the data collected by Swift’s Ultraviolet/Optical Telescope,” said Alice Breeveld, a researcher at the University of London’s Mullard Space Science Laboratory (MSSL) who has worked on the instrument since before the satellite. was launched. “But there was no sign of it. The diversity of this galaxy was entirely in X-rays. This has helped to manage other potential problems.”

Image by NASA’s Swift satellite. Credit: NASA

The discovery of Swift J0230 was possible thanks to a new, automated XRT detector, developed by Evans, called the Swift X-ray Transient Detector.

After the instrument observes a part of the sky, the data is transmitted to the ground, and the system compares it with previous XRT snapshots of the same area. If that X-ray region has changed, scientists have been alert. In the case of Swift J0230, Evans and his colleagues were able to quickly coordinate additional observations of the area.

Swift was originally designed to study gamma-ray bursts, the most powerful explosions in the cosmos. Since the satellite’s launch, however, scientists have realized its potential to study a whole host of celestial objects, such as tidal waves and comets.

“Swift J0230 was only discovered about two months after Phil launched his system,” said S. Bradley Cenko, the mission’s principal investigator at NASA’s Goddard Flight Center in Greenbelt, Maryland. “It shows well the machine’s ability to identify other passing events and Swift’s future to explore new areas of science.”

Reference: “Quasi-periodic lunar explosions from repeated interstellar disturbances by a supermassive black hole” by PA Evans, CJ Nixon, S. Campana, P. Charalampopoulos, DA Perley, AA Breeveld, KL Page, SR Oates, RAJ Eyles-Ferris , DB Malesani, L. Izzo, MR Goad, PT O’Brien, JP Osborne and B. Sbarufatti, 7 September 2023, Natural Astronomy.
DOI: 10.1038/s41550-023-02073-y

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