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- By Rebekah Wilson
- BBC Information NI
Picture supply, ESO/L. Calçada
An artist’s impression of the magnetic white dwarf WD 0816-310 with a steel scar
Astronomers in Armagh have found an indication {that a} star feasted on close by planets and asteroids.
A steel scar discovered on the lifeless star’s floor had by no means been seen earlier than, stated astronomer John Landstreet.
It was found on the astronomical analysis centre in Armagh Observatory and Planetarium.
The scar, believed to be 500km (310 miles) lengthy, was on an Earth-sized remnant of a star from a close-by photo voltaic system.
The system now not creates power at its core, so the star is lifeless.
The white dwarf star has been named WD 0816-310 by the researching astronomers.
Analysis discovered that the scar developed after white dwarf ingested the encircling planets and asteroids which have been born concurrently it, inflicting a focus of metals that scar the celebs floor.
Dr Landstreet, co-author of the analysis paper, is a member of the staff that found the primary magnetic white dwarf in 1970.
“Surprisingly, the fabric was not evenly blended over the floor of the star, as predicted by concept,” he stated.
“As a substitute, this scar is a concentrated patch of planetary materials, held in place by the identical magnetic area that has guided the infalling fragments. Nothing like this has been seen earlier than.”
What’s a white dwarf?
A white dwarf is the burnt stays of a lifeless star – one thing our Solar will change into in about 5 billion years.
When a star dies, gravity means heavier parts transfer towards the centre whereas lighter parts equivalent to hydrogen or helium rise to the outer layer.
At their hottest, the celebs may have hydrogen atmospheres, however as the celebs cool over time they have a tendency to have helium atmospheres.
However typical white dwarfs do not have one aspect of the star devoted to 1 component and the opposite dominated by one other.
At 500km lengthy, the star is about the identical dimension as Vesta – the second-largest asteroid in our photo voltaic system.
Picture supply, ESO/L. Calçada
The analysis used the European Southern Observatory’s Chile based mostly Very Massive Telescope (VLT)
Astronomers stated the power of the steel detection synced with modifications noticed within the star’s magnetic area, which led the staff to find out that the steel scar was positioned on one of many star’s magnetic poles.
This confirmed the metals have been funnelled on to the star by its magnetic area, creating the scar.
Stefano Bagnulo, astronomer at Armagh Observatory and Planetarium, stated it was well-known that some white dwarfs have been cannibalising items of their planetary programs.
“Now now we have found that the white dwarf’s magnetic area performs a key position on this course of, leading to a scar on its floor,” he stated.
