White dwarf star found 'switching on and off' in just 30 minutes for the first time
In a remarkable discovery using NASA’s TESS, astronomers have spotted a white dwarf star ‘switching on and off’ in just 30 minutes for the first time.
- Science News
- 2 min read
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In a remarkable discovery, astronomers have spotted a white dwarf star ‘switching on and off’ in just 30 minutes for the first time. The researchers led by Durham University in the UK said on 18 October that they used NASA's Transiting Exoplanet Survey Satellite (TESS) to observe the unique phenomenon, which has only been previously known to happen over a period of days and months. Utilising TESS data, the team in British university witnessed the phenomena in the solar system TW Pictoris which is 1,400 light-years from Earth.
Our #astronomers have used a planet-hunting satellite to see a white dwarf - what most stars become after they have burned off the hydrogen that fuels them - abruptly switching on and off for the first time. Discover more 👉 https://t.co/qp4GnxGPLe#DUResearch @DurhamPhysics pic.twitter.com/i0xEnJ1PT6
— Durham University (@durham_uni) October 18, 2021
University of Durham researchers said that the particular white dwarf which showed the phenomena is known to be “accreting, or feeding from an orbiting companion star. Our astronomers saw it lose brightness in 30 minutes, a process only previously seen in accreting white dwarfs over a period of several days to months.”
Further elaborating on the incident, the official release stated that the brightness of the accreting white dwarf is impacted by the amount of material surrounding it, which it feeds on. Astronomers believe that what they have witnessed could be the changes to the white dwarf’s surface magnetic field. Notably, when the mode is “on,” the white dwarf star “feeds off” the accretion disc normally before “suddenly and abruptly” the system is “off” and the brightness decreases.
Why the system goes ‘off’?
In the statement, the researchers have also noted that when the system ‘abruptly’ turns ‘off,’ the magnetic field of the white dwarf star is spinning so swiftly that it hinders the amount of ‘food’ that the white dwarf star can receive. This is also called magnetic gating, the astronomers said. The shortage of ‘food’ for the star leads to “semi-regular small increases in brightness seen by the astronomers. After some time, the system sporadically turns “on” again, and the brightness increases back to its original level.”
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The full research paper has been published in the journal Nature Astronomy and the study was led by Dr Simone Scaringi in Durham University’s Centre for Extragalactic Astronomy. Notably, NASA’s TESS is normally used to spot planets outside of the solar system.