The Absolute Cosmos: Closest death of a star ever observed
In the heart of a spiral galaxy located 215 million light-years away, astronomers have spotted a star getting ripped apart by a supermassive black hole. It is the closest such death of a star ever observed.
For instance, Alpha Centauri is the nearest star system to Earth and it is about four light-years away. Our galaxy Milky Way has the diameter of about 200,000 light years. One light year is the distance light travels in a year which is about ten trillion kilometres.
Though these events are hard to detect as they are often obscured by dust and debris, yet astronomers were lucky enough to study this event shortly after the star was ripped into shreds.
These events occur when a star comes excessively close to a black hole. The tidal forces from the black hole stretches the star and then pulls it so hard that it is torn apart.
This event is called tidal disruption event or TDE. It releases a mega flare of light before the debris of the dying star disappears beyond the event horizon of the black hole.
The flare of light is often partially obscured by a cloud of dust and debris, which makes it difficult to observe for more exceptional details.
This new TDE is named AT2019qiz and it was first observed in September 2019.
As the star is torn apart, some of the resulting debris spaghettifies, fading into a long, thin thread of material that feeds into the black hole. The flare forms due to the strong gravitational and frictional impacts from the black hole.
These impacts heat up the material to such high temperatures that the TDE can outshine the host galaxy for a short period of time.
Such stellar TDEs are almost impossible to predict. To catch the glimpse of the event like AT2019qiz, scientists have to keep surveying the sky. AT2019qiz was observed in the constellation of Eridanus.
Scientists studied the TDE for over six months as the flare became bright and gradually faded away. The event was studied in ultraviolet, optical, X-ray and radio wavelengths.
Mostly the TDEs glow in optical and ultraviolet light. This enables the scientists to work out the masses involved in the event.
The observations of the event showed that the doomed star had roughly the same mass as our Sun and it lost almost fifty percent of that mass to the supermassive black hole.
The black hole itself is more than 1 million times more massive than Sun.
Originally published at https://theabsolutecosmos.blogspot.com.