“Teardrop” shape reveals doomed fate of stars destroyed by Supernova
The discovery of astronomers also highlights one of the very rare star systems that will one day see its white dwarf star rekindle its nucleus.
(CN) – An international team of astronomers and astrophysicists have accomplished the rare feat of imaging two stars locked in the early stages of a doomed dance orchestrated by the deadly pull of a possible supernova.
Cosmic dance involves a high temperature subdwarf star and a white dwarf star orbiting the heavens at a speed of about 100 minutes.
Once stars like our sun have exhausted their source of nuclear fuel, they become white dwarfs, expelling their outer material and ultimately cooling their extremely hot cores over billions of years.
UK-based astronomers were able to collect data on the subdwarf star using NASA’s Transiting Exoplanet Survey satellite, but the white dwarf was initially too bright to be captured using the system.
The brightness of the white dwarf faded over time, suggesting distortion caused by the immense gravity of a nearby object, according to the study.
Using radial and rotational speed measurements from the Palomar Observatory and the WM Keck Observatory, astronomers photographed the hidden white dwarf and found it to be as heavy as our Sun, but more smaller than the radius of the Earth.
Scientists’ observations show that stars are still in the early stages of their spiraling loss, according to the study published Monday in the journal Nature Astronomy.
Lead author Ingrid Pelisoli from University of Warwick said in a declaration published with the study the team of scientists does not yet know how the supernovae explode, only that the explosion is a guarantee.
“One way is that if the white dwarf accumulates enough mass from the hot sub-dwarf, so that the two orbit and come together, matter will start to escape from the hot sub-dwarf and fall on the white dwarf.” said Pelisoli. “Another way is that because they lose energy from the emission of gravitational waves, they will move closer together until they merge. Once the white dwarf has gained enough mass with the either method, it will become a supernova.
The path the two stars are on directs them toward a supernova – the largest explosion event found in the cosmos and facilitated by the collapse of a white dwarf’s dense core – which is expected to occur in around 70 million years. ‘years.
The supernova that will eventually consume the stars is known as Type Ia, a sort of cosmic event whose brightness allows astronomers to determine how fast the universe is expanding.
“The more we understand how supernovae work, the better we can calibrate our standard candles,” Pelisoli said. “This is very important right now because there is a gap between what we get from this type of standard candle and what we get. The more we understand how supernovae are formed, the better we can understand if this gap we are getting. observe is due to new physics that we are not aware of and that we do not take into account, or simply because we underestimate the uncertainties in these distances.
Type Ia supernovae occur when the reignition of the nucleus of a white dwarf star triggers a thermonuclear explosion.
The star system where the study objects were observed, categorized as HD265435, is located approximately 1,500 light years from Earth.
Scientists said the star system is also one of the few systems discovered that contains a white dwarf with a nucleus that will eventually reignite, according to the study.
“There is another gap between the estimated and observed galactic supernovae rate and the number of progenitors we are seeing,” Pelisoli said. “We can estimate how many supernovae are going to be in our galaxy by looking at many galaxies, or by what we know about stellar evolution, and that number is consistent. But if we are looking for objects that can become supernovae, we We don’t have enough. This finding was very helpful in estimating what hot dwarf and white dwarf binaries can bring. It still doesn’t seem like much, none of the channels we observed seem to be enough. “