Star collides with itself as it's shredded apart by a black hole

Scientists find even more evidence that black holes are incredibly messy eaters.
Chris Young
An artist's impression of a TDE.
An artist's impression of a TDE.

NASA / JPL-Caltech 

A team of space scientists from Finland, Greece, and the U.S. discovered evidence suggesting that polarized optical emissions observed during tidal eruption events are caused by colossal, clashing streams of material from a destroyed star.

The team of scientists, who published their findings in the journal Science, analyzed a tidal disruption event in the WISEA galaxy. According to a press statement, they used state-of-the-art computer simulations to help determine the cause of the polarized optical emissions.

Black holes shred stars like spaghetti

Black holes are believed to be incredibly messy eaters, and the new findings provide further evidence that this is, indeed, the case.

Scientists have known for some time that black holes can stretch out stars that come close enough. They essentially break the stars up into long strands in events known as tidal disruption events (TDEs). This spaghetti-like star material tends to light up as it circles the black hole before being swallowed.

The team behind the new paper specifically set out to study the source of the bright light of a specific TDE strand. To reach their findings, they used data from the Nordic Optical Telescope, which had captured a TDE in action, and software from the High Energy Astrophysics Science Archive Research Center.

The scientists found that material left over from the TDE circled around the entire black hole. As it did so, it grew hotter and brighter. Their observations showed them that optical polarization measurements surrounding the TDE varied during the event. They peaked with a linear polarization degree of 25 ± 4%.

Polarization measurements shed light on tidal disruption event

Such a high degree of polarization suggests the presence of a relativistic jet, the researchers explained in their paper. However, eight months later, they hadn't detected any radio emissions, and these would have been present if the emissions were, indeed, associated with a relativistic jet.

Polarization refers to the orientation of the oscillation of electromagnetic waves, or light waves. In other words, it shows the direction in which light waves are vibrating. Astronomers can use these readings to glean information about the magnetic fields of distant cosmic objects, as well as other properties that help to shed light on a range of different phenomena.

Using computer simulations, the astronomers came up with an alternative to the relativistic jet hypothesis. They found that it was likely that material left over from the TDE encircled the black hole. As it made its way around the black hole, it encountered similar material circling the black hole from the opposite direction. When these two streams of material collided, they produced a massive shockwave, which resulted in the high polarization observed by the astronomers.

Add Interesting Engineering to your Google News feed.
Add Interesting Engineering to your Google News feed.
message circleSHOW COMMENT (1)chevron
Job Board