A tiny star has been spotted forming from the off-cast remnants of its much larger neighbour in a process previously thought to only create planets.
Astronomers were studying an infant star, called MM 1a, when they spotted an unexpected companion in orbit around it.
MM 1a is a massive star that weighs 40 times the mass of our sun and is surrounded by a rapidly rotating disc of gas and dust.
Closer analysis revealed a much smaller star, only half the mass of our sun, orbiting it.
A tiny star has been spotted forming from the off-cast remnants of its much larger neighbour. MM 1a is a massive star that weighs 40 times the mass of our sun and is surrounded by a rotating disc of gas and dust half the mass of our sun
The team say this is one of the first examples of a ‘fragmented’ disc to be detected around a massive young star.
It is believed the star is forming in the same way that our planet was, from a mass of swirling space debris in the orbit of a giant sun.
A disc of dust and gas surrounds the newly forming star and as it spins at high speed this material clumps together to form planets.
Astronomers from the University of Leeds were investigating the surrounding rotating disc of gas and dust and detected a faint object, MM 1b, in orbit around MM 1a.
Research Fellow Dr John Ilee from the School of Physics and Astronomy at the University of Leeds explained: ‘Stars form within large clouds of gas and dust in interstellar space.
‘When these clouds collapse under gravity, they begin to rotate faster, forming a disc around them.
‘In low mass stars like our sun, it is in these discs that planets can form.
‘In this case, the star and disc we have observed is so massive that, rather than witnessing a planet forming in the disc, we are seeing another star being born.’
By measuring the amount of radiation emitted by the dust, and subtle shifts in the frequency of light emitted by the gas, the researchers were able to calculate the mass of MM 1a and MM 1b.
Dr Ilee added: ‘Many older massive stars are found with nearby companions
‘But binary stars are often very equal in mass, and so likely formed together as siblings.
‘Finding a young binary system with a mass ratio of 80:1 is very unusual, and suggests an entirely different formation process for both objects.’
By measuring the amount of radiation emitted by the dust, and subtle shifts in the frequency of light emitted by the gas, the researchers were able to calculate the mass of MM 1a and MM 1b (pictured). The binary system has a mass ratio of 80:1 whi his highly unusual
The favoured formation process for MM 1b occurs in the outer regions of cold, massive discs.
These ‘gravitationally unstable’ discs are unable to hold themselves up against the pull of their own gravity, collapsing into one, or more, fragments.
Co-author Associate Lecturer Dr Duncan Forgan from the Centre for Exoplanet Science at the University of St Andrews, added: ‘I’ve spent most of my career simulating this process to form giant planets around stars like our Sun.
‘To actually see it forming something as large as a star is really exciting.’
The researchers note newly-discovered young star MM 1b could also be surrounded by its own circumstellar disc, which may have the potential to form planets of its own.
The risk to this planetary system is that they have a lifespan of a million years before the nearby supermassive star goes supernovae and likely vaporises them.
WHAT IS A SUPERNOVA AND HOW DOES IT FORM?
A supernova occurs when a star explodes, shooting debris and particles into space.
A supernova burns for only a short period of time, but it can tell scientists a lot about how the universe began.
One kind of supernova has shown scientists that we live in an expanding universe, one that is growing at an ever increasing rate.
Scientists have also determined that supernovas play a key role in distributing elements throughout the universe.
In 1987, astronomers spotted a ‘titanic supernova’ in a nearby galaxy blazing with the power of over 100 million suns (pictured)
There are two known types of supernova.
The first type occurs in binary star systems when one of the two stars, a carbon-oxygen white dwarf, steals matter from its companion star.
Eventually, the white dwarf accumulates too much matter, causing the star to explode, resulting in a supernova.
The second type of supernova occurs at the end of a single star’s lifetime.
As the star runs out of nuclear fuel, some of its mass flows into its core.
Eventually, the core is so heavy it can’t stand its own gravitational force and the core collapses, resulting in another giant explosion.
Many elements found on Earth are made in the core of stars and these elements travel on to form new stars, planets and everything else in the universe.
Astronomers from the university of Leeds were investigating the surrounding rotating disc of gas and dust and detected a faint object, MM 1b, just beyond the disc in orbit around MM 1a (pictured)
Dr Ilee said: ‘Stars as massive as MM 1a only live for around a million years before exploding as powerful supernovae, so while MM 1b may have the potential to form its own planetary system in the future, it won’t be around for long.’
The surprising discovery was made by using a unique new instrument situated high in the Chilean desert – the Atacama Large Millimetre/submillimetre Array (ALMA).
Using the 66 individual dishes of ALMA together in a process called interferometry, the astronomers were able to simulate the power of a single telescope nearly 2.5 miles (4km) across, allowing them to image the material surrounding the young stars for the first time.
The team have been granted additional observing time with ALMA to further characterise these exciting stellar systems in 2019.
The upcoming observations will simulate a telescope that is 10 miles (16km) across – comparable to the area inside of the ring-road surrounding Leeds.
The study was published in the Astrophysical Journal Letters.
WHAT IS ALMA?
Deep in the Chilean desert, the Atacama Large Millimetre Array, or ALMA, is located in one of the driest places on Earth.
At an altitude of 16,400ft, roughly half the cruising height of a jumbo jet and almost four times the height of Ben Nevis, workers had to carry oxygen tanks to complete its construction.
Switched on in March 2013, it is the world’s most powerful ground based telescope.
It is also the highest on the planet and, at almost £1 billion ($1.2 billion), one of the most expensive of its kind.
Deep in the Chilean desert, the Atacama Large Millimetre Array, or ALMA, is located in one of the driest places on Earth. Switched on in March 2013, it is the world’s most powerful ground based telescope