The universe is full of amazingly massive explosions. Gamma-ray bursts in distant galaxies are literally everyday occurrences, while supernovae are even more common, with astronomers observing hundreds each year.
See also: Hundreds of stars disappeared without a trace, what happened?
But one type of cosmic catastrophe is the rarest and most mysterious. These are sudden, intense bursts of mostly blue light that astronomers call luminous fast blue optical transients (LFBOTs). Just seven have been detected since 2018, and one of them recently did something very strange, even by LFBOT standards. After the initial explosion had died down, the LFBOT continued to flare up—not once but multiple times. This means that a dead star in a distant galaxy has probably come back to life.
Cornell University astronomer Anna Hoand her colleagues hope that studying this strange behavior will help us discover what causes LFBOTs, and their latest research was published this week in the journal Nature.
Ho and other astronomers spotted this strange LFBOT, nicknamed the “Tasmanian Devil ,” from the Zwicky Transient Facility at Palomar Observatory in southern California. This facility has a camera mounted on a telescope that scans the entire night sky every few nights, looking for any light sources that suddenly appear, disappear, or change. Detecting any LFBOTs is a major feat, since astronomers have seen so few of these bright bursts and know very little about what causes them.
See also: Starfield: Loses entire stars when running on AMD Radeon GPUs
A few months after the initial detection of LFBOT, Ho and colleagues were monitoring the residual brightness of this momentary event via ultraviolet light and radio waves, when suddenly the same location in space brightened again, only to disappear again within a few minutes.
Ho and her team enlisted the help of astronomers from more than fifteen other telescopes around the world, and within the first three months after the first LFBOT, the Tasmanian Devil flared up again at least 14 times. Unlike LFBOT, these outbursts were red and faded much more quickly, Ho tells Inverse, but they were unmistakably from the same source.
Astronomers disagree about what causes LFBOTs, but the prevailing ideas seem to be linked to something terrifying happening to a star. LFBOTs could be a still-unknown type of supernova, triggered by the blazing end of a particularly massive star, or they could also be the result of a massive star collapsing into a black hole. However, this new study suggests that the strange flashes observed last fall offer at least one clue: whatever is powering these destructive explosions must be leaving behind either a black hole or a magnetic neutron star called a magnetar.
However, another possibility is that LFBOTs are the explosive result of a collision between a star and a neutron star or black hole.
See also: NASA's Hubble spots black hole creating 'star trails'
"We've never seen anything like this before – something as fast and as bright as the initial explosion, months later – in any supernova or FBOT. This is something we've never seen in astronomy," Ho said in a recent statement.
Source: inverse
