Astronomers have discovered a new cosmic phenomenon in which a white dwarf star becomes “off”, the brightness decreases and the intensity increases within 30 minutes.
The discovery was based on NASA’s search for extraterrestrial planets, described by a team of astronomers at the University of Durham and their partners around the world as “extraordinary.”
At first they thought the fluctuations would interfere with feeding a white dwarf from a sub-star that was part of a binary system – but they did not expect the cause to be unique.
The flow of matter from the donor star to the main white dwarf is subject to gravity, so it must be relatively constant, so there is no obvious reason for such a short-term change as the brightness of the star.
The continuous and rapid recovery of the magnetic field of the white dwarf’s surface – something that the researchers realized was unprecedented.
The binary system called TW Pictoris is about 1,400 light years away from Earth.
Normally, when its white dwarf is “on”, the star feeds on its companion, glowing in space – but sometimes when it stops, the star fades and disappears.
This has been seen before, but it usually does not happen so fast.
According to research published in natural astronomy, a white dwarf has an unusually fast magnetic field that spins very fast and prevents it from reaching the main star.
Leading author Dr. Simon Skarringi, who works at the Extracalactic Astronomical Center in Durham, said: “The differences in brightness we see in white dwarfs are usually slow, and they last from days to months.
“It’s unusual to see the brightness of DW Pictoris in 30 minutes because it’s not in other white dwarfs,” he said.
Dr. Scaringi explained to Sky News: “The comparative process for adding white dwarfs is generally relatively smooth and there are no short-term‘ gaps ’in bright differences.
“What usually happens in these types of systems is that the donor star feeds on the disk in orbit around the white dwarf.
When the aggressive disk material slowly sinks towards the white dwarf, it usually glows, eventually forming on the surface of the white dwarf.
“In some systems, it is known that donor stars stop feeding the disk,” he said, although scientists have not yet figured out why this happens, but the disk will be bright for a while when that happens. Pre-existing products.
“Then it took one to two months for the disk to expel most of the material, and we saw different white dwarfs,” Dr. Scaringi explained.
When the body is completely inactive it is called the ‘magnetic supply’: the rotating magnetic field barrier of the white dwarf prevents the upper left disk material from aligning evenly, but instead begins to control the size of the white dwarf landing on the fits
“Since it takes several months to discharge the disk, reducing the brightness of TW Pictoris in 30 minutes is completely unexpected,” he added.
What we mean with DW Pictoris is that instead of emitting the disk very quickly, we see some sort of reconstruction of the dwarf’s white magnetic field, which immediately pushes the edge of the inner disk out, causing it to spin until the disk is pushed back inside. “
“This is actually a previously unrecognized event,” Dr. Scaring said.
“Since we can compare similar behaviors in young neutron stars, this is an important step in understanding how objects and other important magnetic fields around them play an important role in this process.”