New Light on Stellar Death
New observations suggest that the brightest supernova ever seen,
announced last year, is in fact the violent shredding of a star by the
powerful gravity of a supermassive black hole.
The suspected supernova, dubbed ASSASN-15lh, originally was spotted by an automated, worldwide network of telescopes known as the Las Cumbres Observatory (LCO). The location of the bright event, presumably within a galaxy, was not discernible from the LCO dataset, however.
Now, new Hubble observations have revealed that the event happened near the center of a galaxy, where a supermassive black holes lurks. Considered alongside some of the unexplained quirks in the event’s light signature, the evidence tilts in favor of a star being torn apart, rather than a star exploding of its own accord, a new study argues.
The destruction of a star that strays too close to a black hole is called a tidal disruption. Scientists value these rarely observed events for the insights they can provide about the varying properties of black holes.
“ASASSN-15lh is similar in some ways to the other events we’ve been seeing but is different in ways we didn’t expect,” said study co-author Iair Arcavi, principal investigator of the LCO program that observed ASASSN-15lh, in a press release from the University of California, Santa Barbara (UCSB). Arcavi is an Einstein postdoctoral fellow and a postdoc at UCSB’s Kavli Institute for Theoretical Physics. “It turns out that these events — and the black holes that make them — are more diverse than we had previously imagined.”
An artist’s depiction of a rapidly spinning supermassive black hole surrounded the rotating leftovers of a star that was ripped apart by the tidal forces of the black hole.
This artist’s impression depicts a sun-like star close to a rapidly spinning supermassive black hole, with a mass of about 100 million times the mass of the sun, in the center of a distant galaxy. Its large mass bends the light from stars and gas behind it. Despite being way more massive than the star, the supermassive black hole has an event horizon which is only 200 times larger than the size of the star. Its fast rotation has changed its shape into an oblate sphere. The gravitational pull of the supermassive black hole rips the the star apart in a tidal disruption event. In the process, the star was “spaghettified” and shocks in the colliding debris as well as heat generated in accretion led to a burst of light.
This artists impression shows a black hole consuming a star that has been torn apart by the black hole’s strong gravity. As a result of this massive “meal” the black hole begins to launch a powerful jet that we can detect with radio telescopes.
New Light on Stellar Death
The suspected supernova, dubbed ASSASN-15lh, originally was spotted by an automated, worldwide network of telescopes known as the Las Cumbres Observatory (LCO). The location of the bright event, presumably within a galaxy, was not discernible from the LCO dataset, however.
Now, new Hubble observations have revealed that the event happened near the center of a galaxy, where a supermassive black holes lurks. Considered alongside some of the unexplained quirks in the event’s light signature, the evidence tilts in favor of a star being torn apart, rather than a star exploding of its own accord, a new study argues.
The destruction of a star that strays too close to a black hole is called a tidal disruption. Scientists value these rarely observed events for the insights they can provide about the varying properties of black holes.
“ASASSN-15lh is similar in some ways to the other events we’ve been seeing but is different in ways we didn’t expect,” said study co-author Iair Arcavi, principal investigator of the LCO program that observed ASASSN-15lh, in a press release from the University of California, Santa Barbara (UCSB). Arcavi is an Einstein postdoctoral fellow and a postdoc at UCSB’s Kavli Institute for Theoretical Physics. “It turns out that these events — and the black holes that make them — are more diverse than we had previously imagined.”
An artist’s depiction of a rapidly spinning supermassive black hole surrounded the rotating leftovers of a star that was ripped apart by the tidal forces of the black hole.
This artist’s impression depicts a sun-like star close to a rapidly spinning supermassive black hole, with a mass of about 100 million times the mass of the sun, in the center of a distant galaxy. Its large mass bends the light from stars and gas behind it. Despite being way more massive than the star, the supermassive black hole has an event horizon which is only 200 times larger than the size of the star. Its fast rotation has changed its shape into an oblate sphere. The gravitational pull of the supermassive black hole rips the the star apart in a tidal disruption event. In the process, the star was “spaghettified” and shocks in the colliding debris as well as heat generated in accretion led to a burst of light.
This artists impression shows a black hole consuming a star that has been torn apart by the black hole’s strong gravity. As a result of this massive “meal” the black hole begins to launch a powerful jet that we can detect with radio telescopes.
New Light on Stellar Death
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