Context

Telescopes operated by National Aeronautics and Space Administration (NASA) recently observed a massive black hole devouring a star. The incident was the fifth-closest example of a black hole destroying a star and occurred 250 million light-years from the earth, in the centre of another galaxy.

• The astronomical phenomenon of the destruction of a star by a black hole is formally called a tidal disruption event(TDE).

What is tidal disruption event (TDE)?

• A tidal force is the difference in the strength of gravity between two points.
• If the tidal force exerted on a body is greater than the intermolecular force that keeps it together, the body will get disrupted.
• During a TDE, the tidal force of a black hole disrupts the star in vicinity.
• While about half of the star’s debris continues on its original path, the other half is attracted by the black hole’s gravitational pull.
• The gradual growth of this material bound to the black hole produces a short-lived flare of emission, known as a tidal disruption event.

The latest example

• In the recently-observed example, a dramatic rise in high-energy X-ray light around the black hole was seen once the star was completely ruptured by the black hole’s gravity.
• This indicated the formation of an extremely hot structure above the black hole called a corona.
• According to a study published in Astrophysical Journal, the proximity of the aforementioned TDE provided a spectacular view of the corona’s formation and evaluation.
• The event is formally called AT2021ehb, and took place in a galaxy with a central black hole about 10 million times the mass of our sun.
• It was first spotted on March 1, 2021, by the Zwicky Transient Facility in Southern California. Around 300 days later, the Nuclear Spectroscopic Telescopic Array (NuSTAR) – NASA’s most sensitive space telescope capable of observing high-energy X-rays – began observing the system.