Should the Healthcare Sector Adopt Black-Box AI?

James Cain on 23 October 2024

AI is arguably the most talked about topic of recent times and I am sure that everybody who has read about, or thought about AI, has their own intuition on how it could change the world. This article seeks to stimulate thought and discussion on two opposing perspectives on the adoption of AI. To frame this discussion, I will first introduce a neural network (a computer which can learn and make decisions like the human brain) that is able to detect breast cancer before doctors; it is called Mirai.

Regina Barzilay, Professor of Computer Science at MIT, was driven to develop a computer like Mirai, after developing breast cancer despite undergoing regular mammograms (breast X-Rays) from her doctor and repeatedly getting the all-clear.

Barzilay and her team trained the computer by feeding it millions of mammograms from women who had been deemed cancer free by a doctor and subsequently been diagnosed with breast cancer. Mirai established patterns in the mammograms, identifying features which the human eye cannot see or are over-looked by doctors. Mirai’s predictions were compared with those of doctors, considering all the relevant risk factors, and it was found that Mirai’s predictions were nearly twice more accurate than doctors. Essentially, Mirai can see where cancer will develop or see cancer at its earliest stages.

Mirai is a black-box AI. This means that humans can be certain on what Mirai produces, but not certain on how Mirai produces this output. Black-box AI is built up of several layers with varying functions, the layers identify different features of an image, however the links between these layers are non-linear, meaning it is not clear how the layers interact. Ultimately, the complexity of these systems means that their methods of producing results are unknown, even to the developers. 

Although, Mirai could be used to diagnose millions of women across the world with breast cancer at an earlier stage, the AI has not been adopted by the healthcare sector in the way you might expect. One Oncologist said, “The first rule of medicine is to do no harm.” Healthcare professionals feel uneasy about using a practice which they are completely unable to understand. Whereas Barzilay asserts that because Mirai has been proven to be more effective than the current process, the black-box argument should not be part of the discussion.

Where the results are proven, is it reasonable to require an explanation as to a black-box AI’s method?

Imagine a world where humans and goldfish could communicate with one another. The goldfish asks his owner: “Please explain to me why you pour those pellets into my tank every day?” To answer this question, the owner must explain why they keep the goldfish and sustain it’s life, what the pellets are, what role the pellets play in keeping the goldfish alive and why the pellets must be poured into the tank. To explain the first proposition alone, the owner would have to explain the great extent of human development that makes it feasible for humans to keep goldfish in their homes, and what satisfaction they receive from doing so. One would argue that there is no possible way of explaining these matters to an animal whose brain is less than 1.5cm long. In considering that the goldfish is dependent on its owner’s benefaction to stay alive, does the pesky goldfish deserve this laborious explanation, which is surely incomprehensible to the goldfish, or should the fish keep swimming and eat its pellets?

Image Credit: Pexels – Mart Production

This analogy provides a whimsical illustration of the argument in favour of adopting Mirai in hospitals. It serves to demonstrate that regardless of whether humans can understand how Mirai works, the results are proven. These results would have a significantly positive impact to ensure that women with breast cancer receive earlier, less invasive treatment and potentially have their lives saved. These results could benefit millions of women and their families across the world, regardless of Mirai’s hidden methodology.  

Consider an alternative scenario, of future Britain. A new political party emerges who promises that they can bring ultimate prosperity and happiness to the country. However, because of the hypothetical politicians’ superior intelligence, they announce that their government will completely lack transparency and accountability to the citizens. This is because the citizens could not comprehend the highly complex governmental inner workings. There are many people who would say, “Yes, I would vote for this party, because of their proven results.” Yet, how could you be sure that these results will always be achieved, will their governmental methods produce the same results when the country suffers a drought, or invasion? Possibly, but there is nothing to support any conclusion. Even if you could trust this government based on their past results, their lack of transparency and accountability means you could never be certain on whether this government will get things right.   

The preceding analogy highlights some of the potential risks with adopting and relying on black-box AI. There is a huge danger that one false output from Mirai could cause a person to not receive cancer treatment where they need it, or alternatively are caused to suffer through invasive treatment that they do not need. An exhaustive list of the potential dangers is impossible because of one’s lack of understanding on how Mirai works. The benefits which AI like Mirai could have, are potentially immeasurable, yet so are the drawbacks. The possibility that humans will one day understand the methods of black-box AI is not precluded. So surely, the day humans can fully comprehend black-box AI is the day that we can be more comfortable with its adoption.

What do you think?

Game-Changing Innovations: The Latest in Sustainable Technologies, Renewable Energy, and the Battle Against Climate Change (June–October 2024)

Longoae Domingos Tembwa on 21 October 2024

Over the past few months, significant advancements in sustainable technologies have emerged, as industries and governments intensify their efforts to combat climate change. Innovations in renewable energy generation, storage, carbon capture, and the circular economy are moving at a rapid pace, signalling hope in the fight against global warming. Let’s explore some of the most notable developments from June to October 2024, and their potential to reshape global responses to the climate emergency…

Solar Energy: Greater Efficiency and New Solutions

Solar energy continues to lead the renewable energy charge with groundbreaking innovations. In September, European researchers announced a new world record for solar efficiency: 33.7% in tandem perovskite-silicon solar cells. This leap integrates perovskite layers with silicon to capture more sunlight, resulting in higher energy output. These advanced cells could significantly lower solar energy costs, accelerating the transition to renewable power sources globally.

Moreover, solar energy storage is evolving rapidly. In Spain, a project utilising molten salts for thermal energy storage is in development. These salts can store excess solar energy produced during daylight hours, before releasing it at night. Such technology promises to overcome one of the major challenges facing solar power—its reliance on sunlight—and could make solar a 24/7 energy source, enhancing its reliability for large-scale deployment.

Gemasolar Power Plant, Spain, which uses molten salts for thermal energy storage.
Image Credit: Stocksy

Wind Energy: Offshore Expansion and Innovative Designs

As for wind energy, the sector is making significant strides, particularly in offshore projects. In July, Norway inaugurated the world’s largest floating wind farm, which generates 2 gigawatts of power, enough to supply over 1 million homes. Floating wind turbines are a significant development since they can be deployed in deeper waters where winds are stronger and more consistent. This advancement opens new possibilities for wind energy in countries with deep coastal waters, such as Japan and the United States, which are currently limited by conventional offshore wind technology.

Onshore wind technology is also evolving. Spain is testing a bladeless wind turbine design that uses oscillating rods to generate electricity. This turbine operates without the visual and noise pollution associated with traditional turbines, potentially expanding wind energy in urban or densely populated areas where conventional turbines face resistance.

Wind turbines in Spain trialling bladeless designs.
Image Credit: Energy Magazine

Battery Technology: Pioneering Long-Term Energy Storage

Energy storage remains a key challenge for renewable energy, but several promising breakthroughs have emerged. For instance, Iron-air batteries, showcased in August 2024 by U.S. company Form Energy, are generating excitement due to their ability to store energy for days rather than hours. This breakthrough makes iron-air batteries a game-changer for renewable energy systems, enabling more stable energy grids even during periods of low sunlight or wind.

Form Energy’s iron-air batteries.
The basic principle of operation is reversible rusting.
While discharging, the battery breathes in oxygen from the air and converts iron metal to rust.
While charging, the application of an electrical current converts the rust back to iron and the battery breathes out oxygen.
Image Credit: Form Energy

At the same time, solid-state batteries are nearing commercial viability, particularly for electric vehicles. In September, Toyota revealed its prototype solid-state battery, which offers faster charging, longer range, and improved safety compared to lithium-ion batteries. This technology is expected to be integrated into Toyota’s next-generation EVs by 2025 and could significantly boost the adoption of EVs, which are crucial for reducing emissions in the transport sector.

Green Hydrogen: A Clean Energy Frontier

Green hydrogen is rapidly gaining momentum as a clean fuel for industries that are difficult to electrify, such as shipping, aviation, and heavy manufacturing. In July, the European Union launched the Hydrogen Valley initiative, which aims to establish over 100 hydrogen hubs by 2030. These hubs will become centres for hydrogen production, storage, and distribution, thus accelerating the adoption of hydrogen as a sustainable energy source across Europe.

In Australia, the construction of the world’s largest green hydrogen production facility began in August. Set in Western Australia, the facility aims to produce 10 gigawatts of hydrogen annually by 2030, providing clean energy for both domestic use and export. The rise of green hydrogen projects similar to this is expected to drive down costs, providing a viable alternative to fossil fuels.

Circular Economy and Sustainable Materials: Reducing Waste

Advancements in the circular economy are driving significant progress in reducing waste and improving resource efficiency. In September, a consortium of leading electronics manufacturers launched the “Right to Repair” initiative, which aims to extend the life of consumer electronics and reduce electronic waste. This initiative is particularly important for addressing the environmental impact of e-waste, which contributes millions of tons of global waste each year.

At the same time, sustainable materials are seeing a push forward. In August, a new biodegradable plastic alternative made from seaweed and shrimp shells was introduced to the market. This material, which decomposes in a few weeks, could be a major step toward addressing the global plastic pollution crisis. If widely adopted, it could significantly reduce the amount of single-use plastic waste in oceans and landfills.

A new biodegradable plastic alternative using shrimp shells.
Image Credit: HuffPost UK

Conclusion: Progress with Challenges Ahead

The recent months have witnessed significant advancements in sustainable technologies, from improved solar and wind systems to breakthroughs in battery storage and green hydrogen. These developments provide hope for tackling climate change, but scaling these technologies and ensuring global adoption will be critical. Investment, policy alignment, and international cooperation will be key in determining their long-term impact on global emissions.

As the world continues to innovate and push the boundaries of renewable energy and sustainability, recent breakthroughs suggest that the path to a low-carbon future is increasingly within reach. The next decade will be crucial in determining how these innovations can help mitigate the worst impacts of climate change and transform global energy systems for good.

Launch Your Time at Leeds – Rocketry; Not Just for Engineers

Holly Ullyott on 7 April 2024

Leeds University Rocketry Association is a team of extraordinary young Engineers, Scientists, and other interdisciplinary students making rocket science look easy. Founded in 2021 by just eight students, the team were indomitable in persevering through uncertainty surrounding funding and workspace, ultimately designing, manufacturing, and testing a simple but robust rocket, the Gryphon I. Their growing team went on to enjoy international success at the Spaceport America Cup where Leeds’ first rocket achieved an apogee (height) of 10,000ft (3km) placing the team 2nd for Innovative Design and gaining a perfect score for their Technical Report. Having demonstrated their affinity for success, the team got back to work in Leeds designing not only two rockets, Gryphon II and Pathfinder, but also launching Project Silverback, a dedicated research and development branch currently engineering Leeds’ first-ever liquid-propellant rocket engine – designed from scratch.

How Can I Get Involved with LURA?

In LURA’s short history, 55 students from diverse disciplines and backgrounds, from engineering to physics, media, marketing, and business, have helped to write Leeds history. During this time, the recruitment process has evolved as much as LURA has. Today, LURA proudly hosts the LURA Academy, a series of week-long projects and training in which candidates learn from experienced team members about applying their skills to rocket science and business operations. The Academy aims to simulate life and work as a LURA team member; from rocket science to media and finances, candidates are fully immersed in LURA’s professional rocketry team. One successful candidate described the experience as “life-changing” and illustrated their amazement at their achievements saying “[her participation] opened [her] eyes to new and endless possibilities”.

Alternatively, Project Aptos, which focuses on the development of an active stabilisation system and involves the development of Pathfinder, is being hosted by the Faculty of Engineering and Physical Sciences as a Masters Project. The innovation will allow the team’s rockets to maintain a perfectly vertical trajectory during ascent, ultimately unlocking greater apogees.

LURA needs passionate, self-motivated, and gregarious individuals in engineering, physics, business, finance and related fields to keep pushing the boundaries of possibility for Leeds University students. If you feel inspired to join a dedicated, adventurous, and ambitious team, keep an eye on their website below.

Can’t Wait?

You can visit the retired Gryphon I rocket, which was recovered unscathed, in the School of Mechanical Engineering foyer. Here, Leeds’ first-ever rocket hangs proudly at centre stage greeting students old and new, reminding us that the sky is not the limit and that achieving the incredible is within reach. Visit https://leedsrocketry.co.uk/ to find out more.

Could Music be the Solution to Our Disappearing Forests? 

Elizabeth Sprason on 7 April 2024

Noise pollution is a major concern in our community from simply annoying neighbours to affecting our mood and sleep patterns. In the natural world, it is well known that loud noises caused by humans can affect wild animals’ hunting and foraging abilities. However, for mycelium, a type of fungi, certain noises might be beneficial. Researchers at Flinders University have discovered that music helps promote growth in fungi. 

The rate at which Trichoderma harzianum produced spores following regular exposure to a sound at 8kHz was measured by the researchers to prove that ‘ecoacoustics’ can be a viable way of restoring ecosystems.  The use of sounds has previously been helpful to measure soil health but it’s never previously been used as an active solution. 

Fungi play a massive role within the forest ecosystem. Forest Ecology Professor Suzanne Simard at the University of British Columbia discovered the ‘Wood Wide Web’ which is a fungal network that shares resources such as carbon and deliver signals between plant species spanning acres of forest. Similar to the human nervous system, action potentials have been detected within certain species which even suggests the fungi can ‘talk’ to each other. Mycelium species have a symbiotic relationship with the trees as the fungi gain essential nutrients synthesised by the trees (e.g. sugar) which the fungi are unable to produce themselves. In return, forest plants receive access to a pool of difficult-to-find nutrients and can share chemical signals that warn of changes to their environment, for example. This mutual relationship is often threatened by deforestation, intensive farming, and pollution. The Wood Wide Web can take years to fully develop with studies showing that urban plants often don’t fair as well against disease and extreme weather events than their wilder counterparts who have access to a strong web network. Therefore, it is important to find effective ways to rejuvenate fungal species in ecosystems.  

Before you start singing at the top your lungs in the Meanwood Valley, the study found that the most effective frequency for mycelium growth was above 5kHz. Ariana Grande, who is well known for her high pitch singing, can only reach frequencies of around 2600 Hz. The way that the researchers set up the equipment involved placing the samples into attenuation chambers that blocked out any outside noises and stimulated the sample dishes for 30 minutes a day with Bluetooth speakers. Future experiments, lead researcher J. Robinson suggests, should aim to discover whether specific frequencies can promote growth in desirable fungi like the ones in the Wood Wide Web and inhibit the growth of species that are responsible for diseases like pneumonia.  

There may be some time in the future when nature walks won’t just be accompanied by the sound of bird song; forest speakers may begin to play accompanying tracks for the subterranean ecosystem. Improving the growth rate of the fungi will result in an accelerated restoration of natural habitats and improve the resilience of our natural spaces. 

A Consortium of Octopuses

Rosie Bibby on 7 April 2024

Released from the research vessel Falkor in late 2023, a remotely operated vehicle dove into the depths of the Pacific Ocean off the Coast Rican coast. After descending 3km, two low temperature hydrothermal springs were discovered. You may be more familiar with hot hydrothermal vents, which hold a temperature of around 350°C making them easy to identify from their plumes of smoke arising from the sea floor. Contrastingly, low temperature springs warm the water to only about 10°C warmer than the seabed’s average of 2°C and are therefore much harder to identify. 

Previous explorations had ascertained low temperature hydrothermal springs as brooding areas for octopus as they gather to lay their eggs in areas of warmer water. But aboard the Falkor, an incredible discovery was made. These two new springs were found to be home to an octopus and skate nursery, withholding four previously undiscovered species of octopus! Details of each species is yet to be publicly known; however, one has been named the Dorado octopus after the nearby rock formation it was found near.

These new species of octopus have been identified as solitary by the researchers, and this is typical behaviour of deep-sea octopuses. Local scientific knowledge was utilised in these expeditions and the specimens that were collected will be displayed at the University of Costa Rica’s Museum of Zoology, for the locals to enjoy. It is vital to include local knowledge and expertise for biodiversity conservation as it can provide insight into areas and topics that were previously unknown by Western science. Moreover, this project trained local researchers into how to lead future expeditions such as these, to ensure a comprehensive analysis of the species in this area is achieved. 

Having the most up to date knowledge on biodiversity is vital for the formation of conservation policy. Due to the inaccessibility of deep marine environments, it is hard to achieve protection for these areas. Particularly as the prospects of deep-sea mining, which extracts mineral depositions from the seabed, is gathering motion and international legislation prohibiting it is absent. There are vast resources of nickel, cobalt, copper and other metals in the ocean, most of which have been untouched thus far. However, as many countries begin to make a green transition, there is a heightened demand for metals used in electric car batteries, wind turbines and solar panels, most of which can be found in the deep sea.

Although reducing our dependency on non-renewable energy is a positive step towards combatting climate change; the effects of deep-sea mining has proven to be disastrous for animal populations due to noise, vibration, suspended sediment and light pollution. Octopuses, alongside other deep-sea creatures, utilise sound for survival in the absence of light. If deep sea mining persists, this sensory ability will be contested, making navigation for finding food and partners difficult for such animals. Disturbance from mining could be detrimental to our new octopus species. Furthermore, as deep-sea ecosystems act as carbon sinks, destroying these habitats from deep sea mining could have an overall negative impact on the climate. As the International Seabed Authority (ISA) has yet to compile regulations against deep sea mining, the future for these newly discovered octopuses remains uncertain.

Are We Getting Dumber?

Rosie Bibby on 23 December 2023

After millions of years of evolution has bought the human race a brain size of 1600cc compared to that of a chimpanzee at 350cc. However, a recent press release has found a plethora of evidence to suggest human brain size is decreasing; resulting in lower IQs alongside mental health.

Our large brain is substantial but not compared to the 1700cc of a dolphin brain. These differences mostly arise due the nutrients we consume. Professor Micheal Crawford, the director of the Institute of Brain Chemistry and Human Nutrition UK, claims omega-3 DHA, derived from algae, is they key fatty acid that stimulates our brains to express genes. He says this was the factor that “would have powered the increase in brain size and function.” In fact, dolphins are consuming considerably more omega-3 DHA than the average 21st century human.

Omega-3 DHL can be acquired from seafood including mussels, crabs, oysters and fish. The modern human consumes less of these than ever due to the shift in diet away from fats and towards carbohydrates and sugar. This arose from the misconception that it was the fat in our diets causing physical conditions such as heart disease, although evidence now suggests sugar is the biggest factor. The lack of seafood in our diets has led to “increased rates of depression, autism, ADHD and dementia” from lower omega-3 DHL intake; claims the CEO of the charity FoodfortheBrain, Patrick Holford.

Furthermore, Holford recommends if you are following a plant-based diet you “must supplement omega-3 DHL, derived from algae”. Getting a blood test to check your levels can help identify if you are taking the right amount of omega-3. This can be carried out via Food for the Brain’s pin prick test that can be delivered to your door!

If you’re feeling particularly adventurous, brain expert Professor Stephan Cunnane suggests a “shore-based diet” including “frogs, bird’s eggs and aquatic plants” are the best way to increase your brain power.

Professor Crawford also highlights that during pregnancy, a diet poor in omega-3 can lead to the child having learning and emotional problems from the lower IQ. This arises from how the body produces a substitute fat, called oleic acid, to fill the baby’s brain in the absence of omega-3 DHL.

In the past couple of decades it has been measured that IQ scores are falling. This follows the long-term study by Norwegian researchers, analysing the IQ scores of Norwegian men born from 1962-1991.  They found that their scores had been steadily dropping. Ole Rogeberg, head of the research group states “similar studies in Denmark, Britain, France and the Netherlands, Finland and Estonia have demonstrated a similar downward Trent in IQ scores”.  Since the shift in diet to carbohydrates and fatty acids, IQ scores have been on a downward trend at a 7% loss per generation.

The consequences of a lower IQ score and brain size is not only related to intelligence but has been found to increase the risk of developing a mental health condition. A report from the World Health Organisation (WHO), found mental health conditions has risen by 13% and now one in earth people suffer from some form of mental illness. This corresponds with how there were over 100 million antidepressant prescriptions last year, in the UK alone.

“Our genome is adapted to eating the wild foods we ate during our species’ evolution” according to Crawford. So, before you chow down on your plate of chips or bowl of cornflakes, consider the effects these foods will have on your brain. Perhaps a meal containing more aquatic plants or fish will help you finish your assignment, so you can get to the pub sooner!

Reducing Honeybee Stress in the Winter

Rosie Bibby on 23 December 2023

The art of beekeeping dates back to the Egyptians, where they kept honeybee colonies in pottery. It has evolved far from this through revolutionary science and innovation. However, new research suggests there is a common misconception about colonies and their hives that could be putting them at risk.

Image from a temple dated 2400BC evidencing beekeeping (ancient-origins.net)

The misconception is that honeybees (Apis mellifera), huddle together in the hive when under cold temperatures to insulate the colony. In light of this, hives have been built with walls only 19mm thick compared to tree hollows, where natural nests are formed, that can be as thick as 150mm. Previous research found manufactured hives to have up to seven times more heat loss than those found in nature.

New findings from University of Leeds PhD student Derek Mitchell, propose that the bees are being subjected to thermal stress due to the poor insulation of manufactured hives. This evidence comes from studies on the clustering behaviour of bees and observing how heat interacts within the hive. The huddle of bees consists of an inner layer, called the cluster core, and the outer layer, known as the cluster mantle.

Using his background in mechanical engineering, Mr Mitchell discovered that the cluster mantle is acting more like a heat sink than an insulation mechanism. As “the cluster mantle does not meet any (of) the four insulation criteria identified and meets all three heat sink criteria”. This is because, as the bees on the outside of the cluster become cold, they migrate towards the centre and the warmth of the bees that can still produce heat. Consequently, thermal conductivity increases, leading to heat loss as heat moves out from the center of the huddle outwards. There is a complex relationship between the colony and thermo-fluids including heat, radiation, air and water vapour; this needs to be better understood to enable the proper care for domestic honeybees.

Therefore, it was concluded that the clustering behaviour is not a clever insulation mechanism from the colony but a survival reaction to the extreme cold. Mitchell described that “clustering is not a wrapping of a thick blanket to keep warm – but more like a desperate struggle to crowd closer to the fire or otherwise die”. Other survival techniques in bees include eating their own young. Behaviour such as this would want to be avoided as it can damage the colony and reduce the honey yield for the beekeeper. The inadequacy of man-made hives has lead to this behaviour amongst domesticated bees, therefore, efforts need to be made to increase the insulation efficiency of manufactured hives.

Image of hives in a cold landscape (Scott Hall)

This research aims to contribute towards the debate on the ethical treatment of honeybees. With Mitchell aspiring to “raise awareness of the welfare issues and to help educate beekeepers about the complex interaction of the colony enclosure and thermo-fluids”.  When buying honey, you can make more ethical choices based on how the honey has been produced.

Removing honey from the hive on a regular basis can lead to bee population decline. This anthropogenic focused, profit driven method of beekeeping is damaging to honeybees. When buying honey, smaller scale, bee focused companies are recommended for a more ethical choice. A bee centred approach includes more natural and balanced beekeeping which isn’t as stressful on the population.

There is an issue with certifying UK honey as ‘organic’ because it is uncertain whether the bees are visiting only organically grown flowers. Locally sourced honey can be a better choice if you are willing to contact the beekeeper about their practices. The website ‘Ethical Consumer’ contains a list of ethically approved honey brands that can help you make bee-friendly choices if you wish to include honey in your diet. The research paper entitled ‘Honeybee cluster – not insulation but stressful heat sink’ can be found online here.

“Triple Star” Discovery Could Revolutionise Understanding of Stellar Evolution

Zoe Parker on 23 December 2023

Although star formation may be seen as trivial for stars like our sun, some types are more elusive than others. Massive Be type stars are one such example often found in binary systems, where two stars obit each other. “The best point of reference for that is if you’ve watched Star Wars, there are planets where they have two Suns” explains Johnathan Dodd, PhD student and collaborator on the research. However, not much is known about their formation.

A recent discovery was made by Professor René Oudmaijer, PhD student Johnathan Dodd along with PhD student Isaac Radley from the University of Leeds’ School of Physics and Astronomy and two former Leeds academics Dr Miguel Vioque of the ALMA Observatory in Chile and Dr Abigail Frost at the European Southern Observatory in Chile. It suggests that these stars may also exist in triplet systems (where there are three stars orbiting each other), as well as double. This may help to reveal the long-awaited mystery of their formation since their identification via their emission lines in 1866 by Angelo Secchi.

The “triple star” discovery by Professor Oudmaijer and his team was made by using European Space Agency’s Gaia satellite and could cause ripples of excitement in the astrophysics community. It may also aid our understanding of neutron stars, gravitational waves, and black holes.

Principal Investigator Professor Oudmaijer said “there’s a revolution going on in physics at the moment around gravitational waves. We have only been observing these gravitational waves for a few years now, and these have been found to be due to merging black holes.”  

“We know that these enigmatic objects – black holes and neutron stars – exist, but we don’t know much about the stars that would become them. Our findings provide a clue to understanding these gravitational wave sources.” 

He added that “over the last decade or so, astronomers have found that binarity is an incredibly important element in stellar evolution. We are now moving more towards the idea it is even more complex than that and that triple stars need to be considered.” 

“Indeed,” Oudmaijer said, “triples have become the new binaries”.

Video Credit: ESO/L. Calçada eso.org/public/archives/videos/hd_and_apple/eso2204b.m4v (Artist’s animation of what the system could look like)
New research using data from ESO’s Very Large Telescope and Very Large Telescope Interferometer has revealed that HR 6819, previously believed to be a triple system with a black hole, is in fact a system of two stars with no black hole. The scientists, a KU Leuven-ESO team, believe they have observed this binary system in a brief moment after one of the stars sucked the atmosphere off its companion, a phenomenon often referred to as “stellar vampirism”. This animation shows what the system might look like; it’s composed of an oblate star with a disc around it (a Be “vampire” star; foreground) and B-type star that has been stripped of its atmosphere (background).

Their research involved looking for further away secondary stars within various data sets to build a picture that at larger separations the number of companions stars is comparable between Herbig Be and B type stars.

“We observed the way the stars move across the night sky, over longer periods like 10 years, and shorter periods of around six months. If a star moves in a straight line, we know there’s just one star, but if there is more than one, we will see a slight wobble or, in the best case, a spiral.” Mr Dodd explained.

The two types of stars they were most interested in are B and Be; the former displays hydrogen emission lines and the latter are main sequence non-supergiant stars that have Balmer series emission lines.

“We applied this across the two groups of stars that we are looking at – the B stars and the Be stars – and what we found, confusingly, is that at first it looks like the Be stars have a lower rate of companions than the B stars. This is interesting because we’d expect them to have a higher rate” Mr Dodd added.

In a large proportion of the sample analysed had the inference that a third body was influencing the system, resulting in the Be star having a reduced distance from its companion. This causes mass transfer from the two stars as the Be star ‘sucks’ matter from the other. It’s been dubbed a “vampire” Be star and this behaviour forms the characteristic disc around the Be star.

Image credit: ESO/M. Kornmesser/S.E. de Mink (Artist’s impression of a vampire star and its victim | ESO)
Artist’s impression of a vampire star (left) stealing material from its victim: New research using data from ESO’s Very Large Telescope has revealed that the hottest and brightest stars, which are known as O stars, are often found in close pairs. Many of such binaries will at some point transfer mass from one star to another, a kind of stellar vampirism depicted in this artist’s impression.

A reason as to why the companion is hard to spot could be due to them being obscured by the disc and reduced so much by the Be star making them very small and faint.

Professor Oudmaijer said “the fact that we do not see them might be because they are now too faint to be detected.”

This breakthrough has opened up another area of exciting research.

Their paper entitled “Gaia uncovers difference in B and Be star binarity at small scales: evidence for mass transfer causing the Be phenomenon” was published on the 21st November and can be found here.