Slim Boom. Credit: Bill Drury, University of Sheffield
Astronomers have spotted an explosion 180 million light-years away that challenges our current understanding of cosmic explosions, revealing a significantly flatter appearance than previously thought.
- Astronomers have observed an explosion 180 million light-years away that challenges our current understanding of explosions in space, which is much flatter than previously thought.
- Bursts are always expected to be spherical because stars themselves are spherical, but this is the flattest ever seen.
- The observed burst is a very rare Fast Blue Optical Transient (FBOT) – known among astronomers as a “cow” – that only four people have ever seen, and scientists don’t know how they occur, but this discovery helps to solve part of the problem. of the puzzle
- A possible explanation for how this explosion occurred is that the star itself may have been surrounded by a dense disk, or that it may have been a failed supernova.
An explosion the size of our solar system has baffled scientists, as part of its shape — like a very flat disk — challenges everything we know about explosions in space.
The observed explosion was a bright fast blue optical transient (FBOT) – a much less common type of explosion than other explosions such as supernovae. The first bright FBOT was discovered in 2018 and given the nickname “cow”.
Starbursts in the universe are always spherical because stars themselves are spherical. However, the explosion, which occurred 180 million light-years away, was a spherical shape never before seen in space, a disk-like shape that emerged days after its discovery. This part of the burst may have come from material that the star shed just before it exploded.
It is not yet clear how bright FBOT bursts occur, but it is believed that this observation was recently published in the journal. Monthly Notices of the Royal Astronomical SocietyBrings us closer to understanding them.
Lead author of the study, Dr. Justin Mount said: “Very little is known about FBOT bursts – they don’t act like exploding stars, they’re very bright, and they form very quickly. Simply put, they’re strange, and this new observation makes them even stranger.
“Hopefully this new discovery will help shed some more light on them – we never thought the explosions could be this spherical. There are a few possible explanations for this: the stars involved may have formed a disk shortly before they died, or these could be failed supernovae, where the core of the star is a black hole or neutron star. Collapses into a star and then eats the rest of the star.
“What we now know for sure is that the recorded asymmetries are an important part of understanding these mysterious explosions, and it challenges our preconceptions about how stars explode in the universe.”
Scientists made this discovery after accidentally detecting a beam of polarized light. Using the astronomical equivalent of Polaroid sunglasses – they were able to measure the polarity of the burst – with the Liverpool Telescope (owned by Liverpool John Moores University) located in La Palma.
By measuring the polarization, it allowed us to measure the shape of the burst, effectively looking at the size of our solar system, but in a galaxy 180 million light-years away. They were able to use the data to reconstruct the 3D shape of the eruption, and map the edges of the eruption – allowing them to see how flat it was.
The mirror of the Liverpool telescope is only 2.0 m in diameter, but by studying the polarization, astronomers have determined the shape of the burst to be about 750 km across.
The researchers will now conduct a new study with the International Vera Rubin Laboratory in Chile, which is expected to help discover and further understand FBOTs.
Reference: “Polarized optical light pointing to a flash aspherical ‘cow” by Justin R Mount, Peter A Hoflich, Ian A Steele, Yi Yang, Klaus Wiersema, Shiho Kobayashi, Nuria Jordana-Midjohns, Carol Mundel, Andreja Kombok. Cristiano Guidorsi and Robert J. Smith, 21 February 2023, Monthly Notices of the Royal Astronomical Society.
DOI: 10.1093/mnras/stad539
