Scientists at the University of Durham in the UK have used NASA’s Tess (Transiting Exoplanet Survey Satellite) space telescope to observe an unusual phenomenon.

White dwarfs are the end of most stars’ lives when they run out of fuel to sustain fusion reactions. They are about the size of Earth and the mass is very close to the Sun.

TW Pictoris is a binary system that feeds on one of its components – the white dwarf mentioned above – in the case of a co-star. Astronomers have observed that it loses its brightness every 30 minutes, which is a complete record. Previous decreases in white dwarf brightness have been recorded at time intervals ranging from several days to several months.

The brightness of the white dwarf in TW Pictoris depends on the amount of matter around it, so the conclusion is that “something” is likely to interfere with its flow. The new discovery will help us better understand the physics of acrolein, which consumes matter around black holes, white dwarfs and neutron stars from neighboring stars.

TW Pictoris’ binary system is located about 1,400 light-years from Earth. It is made up of a white dwarf that eats a surrounding accretion disk powered by hydrogen and helium from a giant star. When the white dwarf absorbs it, it becomes brighter and brighter. System observations using TESS revealed unprecedented levels of brightness in such situations. Since the flow of matter to the white dwarf accretion disk is relatively constant from its co-star, diving should not occur.

Scientists suspect that the observed changes are due to the rearrangement of the star’s surface magnetic field. When the white dwarf is “on” (when the brightness is high) it absorbs matter from the accretion disk, and when the brightness is low the magnetic field rotates very quickly and no fuel from a neighboring star falls on it. This is called magnetic gating. The magnetic field of this white dwarf controls the amount of fuel passing through the ‘gate’ to the accretion disk, leading to the semi-regular, small spikes of light observed by astronomers. After a while, the system will “turn on” again and the brightness will return to normal.

– Variations in brightness are generally relatively slow in accretion white dwarfs, ranging from days to months. It is remarkable to see the brightness of TW Pictoris within 30 minutes, as it has not been seen in other white accretion dwarfs, and is quite unexpected from the point of view of our understanding of how these systems move through the accretion disk. . It seems to be on and off, said Dr. Simon Skaringi of the University of Durham in the UK.

As there are more white dwarfs than neutron stars in the universe, astronomers hope that future designs will find more of them.