Tag Archives: Spiraling

Prince Harry and Meghan Markle’s Alleged Coronation “Demands” Have the Palace Spiraling Per Usual – Yahoo Life

  1. Prince Harry and Meghan Markle’s Alleged Coronation “Demands” Have the Palace Spiraling Per Usual Yahoo Life
  2. Leaked Coronation Plans Show Meghan Markle and Prince Harry Will Not Be Included In Procession ELLE
  3. Daniela Elser: King Charles makes huge Prince Harry and Meghan Markle blunder New Zealand Herald
  4. Prince Harry and Meghan Markle Are Apparently Making Major Demands in Order to Confirm Their Attendance at the Coronation Yahoo Life
  5. ‘A lot to negotiate’: Meghan and Harry issue demands for King Charles’ coronation Sky News Australia
  6. View Full Coverage on Google News

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Bill Ackman is ‘extremely concerned’ about financial contagion risk ‘spiraling out of control’ after First Republic rescue – Fortune

  1. Bill Ackman is ‘extremely concerned’ about financial contagion risk ‘spiraling out of control’ after First Republic rescue Fortune
  2. ‘We need to stop this now.’ First Republic support is spreading financial contagion, says Ackman. MarketWatch
  3. Elon Musk Reacts As Bill Ackman Flags First Republic’s Risk Spreading To Largest Banks: ‘…Astounding’ – Benzinga
  4. Bewitched: The Bloomberg Open, Americas Edition Bloomberg
  5. Why Bill Ackman fears First Republic rescue threatens banks, economy Markets Insider
  6. View Full Coverage on Google News

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Astronomers Discover an Exoplanet Spiraling Toward Its Destruction

Ashley Chontos, Princeton’s Henry Norris Russell Postdoctoral Fellow in Astrophysics, was part of a team discovering that Kepler-1658b is spiraling to its doom around its aging star, providing a chance to learn more about the fate of other worlds as their solar systems evolve. Chontos also led 2019 effort to confirm that this object was an exoplanet, not the false positive it had believed to be for a decade. Credit: Gabriel Perez Diaz/Instituto de Astrofísica de Canarias

The impending demise of Kepler-1658b as it orbits its aging star offers an opportunity for scientists to gain insight into the fate of other planets and their evolving solar systems.

Astronomers have made a groundbreaking discovery of an

The discovery of an exoplanet whose orbit is decaying as it orbits an aging star provides a new understanding of the gradual process of planetary orbital decay by offering the first glimpse of a solar system in its final stages. The fate of being consumed by a star is believed to be the ultimate destiny for many planets, including Earth in about 5 billion years. According to scientists, the exoplanet Kepler-1568b has less than 3 million years left before it meets its demise.

Ashley Chontos, Princeton’s Henry Norris Russell Postdoctoral Fellow in Astrophysics, was part of a team discovering that Kepler-1658b is spiraling to its doom around its aging star, providing a chance to learn more about the fate of other worlds as their solar systems evolve. Credit: Stephanie Reif, Princeton University Department of Astrophysical Sciences

“We’ve had theorists predict the fates of stars and their planets for decades, but we’ve never before had observations to test them against,” said Ashley Chontos, the Henry Norris Russell Postdoctoral Fellow in Astrophysics at Princeton. “We can also think about this in terms of our own solar system. How long will Earth survive once the sun fuses all its hydrogen into helium? We have some ideas, but ultimately it’s hard to say for certain. These single-planet systems are really important for helping anchor these different theories.”

Chontos is the second author on a new study in the Astrophysical Journal Letters describing the researchers’ observations of the doomed exoplanet.

The first author is Shreyas Vissapragada, a 51 Pegasi b Fellow at Harvard University and the Smithsonian Institution. “We’ve previously detected evidence for exoplanets in-spiraling toward their stars, but we have never before seen such a planet around an evolved star,” he said.

For stars similar to the sun, “evolved” refers to those that have fused all their hydrogen into helium and moved into the next stage of their life. In this case, the star has begun expanding into a subgiant. “Theory predicts that evolved stars are very effective at sapping energy from their planets’ orbits, and now we can test those theories with observations,” Vissapragada said.

The ill-fated exoplanet is designated Kepler-1658b. As its name indicates, astronomers discovered it with the Kepler space telescope, a pioneering planet-hunting mission that launched in 2009. This world was the very first new exoplanet candidate Kepler ever observed, at which point it was dubbed KOI 4.01 — the 4th Object of Interest identified by Kepler. (KOIs 1, 2, and 3 had been identified before Kepler’s launch.)

Early on, KOI 4.01 was dismissed as a false positive. A decade would pass before Chontos, looking at seismic waves moving through its star, realized that the reason the data didn’t fit the model was that the scientists thought they were modeling a

Why? The same phenomenon is responsible for the daily rise and fall of Earth’s oceans: tides.

Tides are generated by when orbiting bodies tug on each other, whether Earth and the moon or Kepler-1658b and its star. Both bodies exert gravitational pulls on each other, but the bigger body always wins, meaning that the smaller body flexes more.

The tugging distorts each body’s shape, and as the planet and star respond to these changes, energy is released. Depending on the distances between them, their sizes, and their rotation rates, these tidal interactions can result in bodies pushing each other away — the case for the Earth and the slowly outward-spiraling Moon — or inward, as with Kepler-1658b toward its star.

There is still a lot researchers do not understand about these dynamics, particularly in star-planet scenarios, so the astrophysicists are eager to learn more from the Kepler-1658 system.

Chontos, who came to Princeton only a few months ago, said that she is looking forward to discussing her findings with the theorists and other astrophysicists here.

“I’m a first-generation, non-traditional student,” Chontos said. “I didn’t apply to Princeton for undergrad or grad school, because I had this vision in my head of what people would be like — and I couldn’t have been more wrong, in the best possible way. They’re doing everything right. There’s a reason why our department has something like 60 postdocs. And at coffee hours and colloquia, I have the opportunity to talk with the people who wrote the theory papers that inspire me.’”

Kepler-1658b’s star has evolved to the point in its stellar life cycle where it has started to expand, just as our sun is expected to, and it has entered into what astronomers call a subgiant phase. Theorists have predicted that the internal structure of evolved stars should more readily lead to the dissipation of tidal energy taken from hosted planets’ orbits compared to hydrogen-rich stars like our Sun. This would accelerate the orbital decay process, making it easier to study on human timescales.

“Even though physically, this exoplanet’s system is very dissimilar to our solar system — our home — it can still tell us a lot about the efficiency of these tidal dissipation processes, and how long these planets can survive,” said Chontos.

Kepler-1658b is about 2 billion years old and is in the last 1% of its life, she said. She and her colleagues predict that the planet will collide with its star in about 3 million years.

For more on this research, see Exoplanet Discovered Spiraling to Ultimate Obliteration Around an Aging Star.

Reference: “The Possible Tidal Demise of Kepler’s First Planetary System” by Shreyas Vissapragada, Ashley Chontos, Michael Greklek-McKeon, Heather A. Knutson, Fei Dai, Jorge Pérez González, Sam Grunblatt, Daniel Huber and Nicholas Saunders, 19 December 2022, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/aca47e

The study was funded by the Science Mission Directorate and the



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QT at the Bank of Canada: Assets Down 24% from Peak. Spiraling Losses on Bonds, to Be Paid for by Canadians

The BoC’s QT started much earlier and is way ahead of the Fed’s QT.

By Wolf Richter for WOLF STREET.

On the Bank of Canada’s balance sheet released Friday, total assets of C$439 billion were down by 24% from the peak in March 2021 (C$575 billion). By comparison, the Fed’s balance sheet peaked in April 2022. The BoC’s Quantitative Tightening (QT) started in essence in April 2021 and is way ahead of the Fed’s QT. We’ll get to the details and the funny-looking shape in a moment:

Biggest categories of QE assets, gone or rolling off:

Repos: The BoC’s repo holdings peaked in June 2020 at C$210 billion, and then started unwinding. Most of them were gone by June 2021, and by June 2022 nearly all of them were gone. Now just C$400 million are left over, waiting to mature (green line in the chart below).

Canada Treasury bills: The short-term Canada Treasury bills that the BoC started purchasing in March 2020 peaked in July 2020 at C$140 billion. At that point, the BoC started to let them roll off the balance sheet when they matured. In March 2021, it announced that it would let them and repos go to zero, citing “moral hazard” as reason. By September 2021, the Treasury bills were mostly gone. By April 2022, they were totally gone, and remain gone today (purple line).

MBS: The BoC never bought a lot of these “mortgage bonds” to begin with. They peaked at just under C$10 billion in late 2020. In October 2020, the BoC said it would end buying MBS entirely, worried about the Canadian housing bubble. They have since then diminished due to the pass-through principal payments and remain a very small item, down to C$9 billion (yellow line).

Government of Canada (GoC) bonds: This is the biggie, the prime QE tool. In October 2020, the BoC announced that it would reduce its purchases of GoC bonds from C$5 billion a week to C$4 billion a week – but don’t call it “tapering,” it said at the time, though it was plain-old tapering.

In April 2021, by which time it held 40% of the outstanding GoC bonds, it reduced its purchases of GoC bonds to C$3 billion, citing “signs of extrapolative expectations and speculative behavior” in the housing market. In July 2021, the BoC reduced its purchases to C$2 billion a week.

In October 2021, it put the hammer down. In a surprise move, with inflation surging, it announced that it would end its purchases of GoC bonds entirely, beginning November 1, 2021, and would allow maturing bonds to roll off without replacement. There are no “caps” on the GoC bonds that roll off. Whatever matures, rolls off. The surprise announcement caused yields to spike.

This was the beginning of its official QT though total assets had already dropped a bunch because repos and Treasury bills had mostly vanished.

The BoC’s holdings of GoC bonds peaked at the end of December 2021 at C$435 billion and have in the eight months since declined by 12.6%, or by $54 billion, to $C381 billion (red line).

“Indemnity:” Losses on its securities holdings.

Note the brown line in the chart above – now the second-largest asset, “Indemnity.” This is the estimated value of the indemnity agreements between the federal government and the BoC. It represents the estimated losses from the securities holdings of the BoC if it were to sell them at current prices, which it would then be reimbursed for by the federal government.

As part of this QE craziness starting in March 2020, the federal government agreed to indemnify the BoC for any actual losses incurred on its bond portfolio. These losses were expected to pile up when bond yields begin to rise, as they’ve been doing since early 2021.

The BoC sets up the estimate of the losses as an asset on this balance sheet. If the BoC actually gets paid from the government for these losses, the amount is reduced by the reimbursement. This account is a form of a receivable, owed to the BoC by the federal government, for the losses on the bond holdings.

When yields rise, those losses rise. When yields fall, the losses decline (all bondholders experience that). During the bear-market summer rally that lasted in Canada, as well as in the US, from mid-June through mid-August, yields fell and bond prices rose.

But this rally ended in mid-August. Since then, yields have been rising and bond prices have been falling, and the estimated losses have also been rising again.

The chart below shows the detail of those estimated indemnities, based on the estimated losses. These indemnities peaked on the balance sheet dated June 15 at C$35 billion. Then, as yields fell and as losses fell, the value of the indemnities fell also, bottoming out at C$26 billion on the balance sheet dated August 10. Then they took off again. On the balance sheet dated August 24, released on Friday, they jumped back to C$31 billion:

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ECB’s Lane sees double-sided risk of spiraling inflation and economic slowdown

Philip Lane, chief economist of the European Central Bank.

Bloomberg | Bloomberg | Getty Images

European Central Bank Chief Economist Philip Lane said the Frankfurt institution will have to remain vigilant over the coming months with the prospect of inflation spiraling ever higher alongside the risk of a consumer-led slowdown the region.

“With the uncertainty, we have to manage the two risks,” Lane, who is also a member of the bank’s Governing Council, told CNBC’s Annette Weisbach Tuesday at the ECB’s Sintra Forum in Portugal.

“On the one side, that could be forces that keep inflation higher than expected for longer. On the other side, we do have the risk of a slowdown in the economy, which would reduce inflationary pressure,” he added.

“So it’s very much having a clear vision for the next couple of meetings, having an orientation to move away from the very low rates we’ve had for quite a few years, but also fully respecting the importance of being data dependent. And to retain the optionality to respond to what we see, in the coming months.”

All eyes are on the ECB with a critical meeting next month. The central bank has said it will be raising interest rates for the first time in 11 years, but investors are more interested in understanding what the ECB is doing to address fragmentation risks in the region.

The euro zone’s central bank held an emergency meeting earlier this month as borrowing costs surged for the so-called peripheral European nations. The ECB said it would be developing a new tool to address these risks — however, markets were left wondering when the tool would be implemented and how far it would go.

These conversations come at a time when there’s widespread concern about the euro zone economy. Inflation is high and the growth outlook is deteriorating.

“Can you really hike interest rates into a recession even if inflation is high? That would be unusual,” Erik Nielsen, the global chief economist at UniCredit, told CNBC Tuesday.

The ECB confirmed in early June its intention to hike rates next month and then again after the summer. This would likely bring the ECB’s deposit rate back out of negative territory and mark a massive moment for the central bank, which has kept rates below zero since 2014.

However, there are questions on whether Lagarde will follow through with multiple rate hikes with the region’s growth outlook darkening.

The ECB in June forecast a GDP rate of 2.8% for the euro zone this year, but economists are starting to talk about the prospect of a recession toward year-end off the back of Russia’s invasion of Ukraine and the impact that’s having on the global economy.

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The Monkeypox Crisis Is Secretly Spiraling in Virus Epicenter of Nigeria

AKAMKPA, Nigeria—The two sons of Destiny, a 48-year-old Nigerian businessman whose nephew had recently contracted the monkeypox virus, are already showing similar symptoms.

They have swollen lymph nodes, which started a couple of days after they developed a fever. Despite the rash on their bodies morphing into pus-filled pimples that have scabbed over, Destiny believes his sons are only feeling the effect of the heat wave sweeping Nigeria’s southeastern Cross River State, where they live. He has prevented his sons—both in their early twenties—from visiting the hospital, believing that the rash “will go away after some time.”

“In less than a week, everything will be gone,” Destiny told The Daily Beast just outside his home in the town of Akamkpa in the southern region of Cross River. “We’ve started applying calamine lotion [a medication commonly used to treat mild itchiness] on it and we’ll soon start seeing results.”

Monkeypox, a viral zoonotic disease caused by a virus transmitted from animals to humans, was first discovered among monkeys kept for research in the Democratic Republic of Congo (DRC) back in 1958, and later in humans in the same country in 1970. The disease is currently endemic in rodent and monkey populations in West and Central Africa, including in Nigeria, where cases are surging and causing flu-like symptoms and rashes in infected people. Recently, the virus has cropped up in Europe and the U.S., raising alarm that the illness could soon spiral into a pandemic.

Few around Destiny’s compound seem to believe the disease really exists. As was the case with some COVID-19 conspiracy theorists, many believe it’s another “so-called” illness conceived by the West for the purpose of introducing vaccines that will reduce the population in Africa. It’s the kind of belief that is already hampering coronavirus vaccination in Nigeria, with only close to 17 million in a country of 200 million people fully inoculated.

“America has started again with another talk of infectious disease outbreak,” one of Destiny’s neighbors murmured as he heard Destiny speaking to The Daily Beast. “They [Americans] saw that Africans didn’t buy into their COVID scam and so introduced this one [monkeypox] to scare people.”

But as many very close to Destiny live in denial, signs that the disease lives very close to them are glaring. A woman who developed a rash and swollen lymph nodes on her body blamed the occurrence on a “spiritual attack” by her enemies, according to her younger sister, and had to run to the home of a traditional medicine practitioner about 200km (120 miles) away for treatment. No one, her sibling said, has seen or heard from her since. Another 80-year-old man who died a week ago was said to have had symptoms of monkeypox, but did not seek medical attention.

Smith Collection/Gado/Getty

“Many people are scared that if they come to hospitals and are diagnosed with the disease, they could be separated from their families and quarantined for a long time,” Dr. Collins Anyachi of the Department of Family Medicine at the university teaching hospital (UCTH) in Calabar, the Cross River State capital, told The Daily Beast. “They’d rather prefer to patronize patent medicine dealers or traditional medicine practitioners who’d only prescribe medicines or herbs and tell them that they’ll get well in a few days.”

Cases like those in Akamkpa show that Nigeria is almost certainly failing to document many monkeypox cases, especially in rural areas, where surveillance has been very poor.

Unlike in the West, the outbreak of the disease in Nigeria, where the illness is endemic, didn’t begin this year. It started in 2017. Between then and now, there have been more than 650 suspected cases with over 260 confirmed, one-seventh of which were recorded in the first half of this year.

But government records in Nigeria, where monkeypox cases are on the rise, don’t tell the true story of the disease that has spiked in Europe and the United States.

Officially, Nigeria has announced 141 suspected cases and 36 confirmed cases from 12 states between January 1 and June 12. But as seen in Cross River State, where official records show only two cases have been confirmed, many who likely have the disease are refusing to seek medical check.

“There’s also the fear of stigmatization,” said Anyachi. “When people are officially diagnosed with monkeypox, there is a tendency that the society will treat them with disdain. We’ve seen that happen a lot with people who suffered from leprosy.”

But beyond the people’s reluctance to visit hospitals, authorities have had challenges monitoring the outbreak of monkeypox. To start with, disease surveillance in Nigeria was generally hampered by the outbreak of COVID-19. In the case of Lassa fever for example, there were nearly 1,200 confirmed cases recorded in the year 2020 when the novel coronavirus emerged. That number came down to 510 in 2021, as overstretched health authorities paid more attention to the more contagious COVID-19. But with COVID no longer as dominant, the number of Lassa fever infections confirmed in the first quarter of 2022 alone rose to 751. Like Lassa fever, there was inadequate attention paid to monkeypox in 2021, meaning many infections went unnoticed.

To make matters worse, countries like the U.S. and U.K. are offering a vaccine produced by Bavarian Nordic—one that was approved for monkeypox by the U.S. Food and Drug Administration in 2019—to high-risk contacts, Nigeria has been unable to obtain vaccines or medicines to prevent and treat monkeypox, a virus the World Health Organization (WHO) says is “transmitted from one person to another by close contact with lesions, body fluids, respiratory droplets and contaminated materials such as bedding.”

At this stage, we cannot begin to spend so much money [in a hospital] when it isn’t life-threatening.

In a country where there are only 40,000 doctors for 200 million people there’s genuine concern that if monkeypox cases expand in poor rural neighborhoods, where there’s over overcrowding and miserable sanitation, Nigeria’s health sector will be unable to handle it.

“The major fear is the possibility of misdiagnosis at primary health-care facilities, which is what’s available to people in rural communities,” Dr. Elijah Akpe Orim, who has worked in community health for many years in Cross River State, told The Daily Beast. “The people you often find in these health centers are community health extension workers who are not professionally trained on how to deal with such cases.”

Because of similarities in symptoms, according to Dr. Orim, who now works at the UCTH pharmacology department, “patients who may be suffering from monkeypox may be erroneously told they’ve been infected with a disease like measles and that doesn’t help in any way.”

As for Destiny, he says that he will only seek treatment in a hospital when his son’s ailments get “out of their control.”

“At this stage, we cannot begin to spend so much money [in a hospital] when it isn’t life-threatening,” said Destiny. “It is too early to waste money.”



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Astronomers Find Two Supermassive Black Holes Spiraling Toward a Cataclysmic Collision

A supermassive

If the team is correct, the diameter of the binary’s orbit is 10 to 100 times smaller than the only other known supermassive binary, and the pair will merge in roughly 10,000 years. That might seem like a long time, but it would take a total of about 100 million years for black holes of this size to begin orbiting one another and finally come together. So this pair is more than 99% of the way to a collision.

Joseph Lazio and Michele Vallisneri, at

In this illustration, light from a smaller black hole (left) curves around a larger black hole and forms an almost-mirror image on the other side. The gravity of a black hole can warp the fabric of space itself, such that light passing close to the black hole will follow a curved path around it. Credit: Caltech/R. Hurt (IPAC)

Evidence that this supermassive black hole may have a companion comes from observations by radio telescopes on Earth. Black holes don’t emit light, but their gravity can gather disks of hot gas around them and eject some of that material into space. These jets can stretch for millions of light-years. A jet pointed toward Earth appears far brighter than a jet pointed away from Earth. Astronomers call supermassive black holes with jets oriented toward Earth blazars, and a blazar named PKS 2131-021 is at the heart of this recent paper.

Located about 9 billion light-years from Earth, PKS 2131-021 is one of 1,800 blazars that a group of researchers at Caltech in Pasadena has been monitoring with the Owens Valley Radio Observatory in Northern California for 13 years as part of a general study of blazar behavior. But this particular blazar exhibits a strange behavior: Its brightness shows regular ups and downs as predictably as the ticking of a clock.

Researchers now think this regular variation is the result of a second black hole tugging on the first as they orbit each other about every two years. Each of the two black holes in PKS 2131-021 is estimated to be a few hundred million times the mass of our Sun. To confirm the finding, scientists will try to detect gravitational waves – ripples in space – coming from the system. The first detection of (function(d, s, id){ var js, fjs = d.getElementsByTagName(s)[0]; if (d.getElementById(id)) return; js = d.createElement(s); js.id = id; js.src = "https://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.6"; fjs.parentNode.insertBefore(js, fjs); }(document, 'script', 'facebook-jssdk'));

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Astronomers Find Two Giant Black Holes Spiraling Toward a Collision

Evidence that this supermassive black hole may have a companion comes from observations by radio telescopes on Earth. Black holes don’t emit light, but their gravity can gather disks of hot gas around them and eject some of that material into space. These jets can stretch for millions of light-years. A jet pointed toward Earth appears far brighter than a jet pointed away from Earth. Astronomers call supermassive black holes with jets oriented toward Earth blazars, and a blazar named PKS 2131-021 is at the heart of this recent paper.

Located about 9 billion light-years from Earth, PKS 2131-021 is one of 1,800 blazars that a group of researchers at Caltech in Pasadena has been monitoring with the Owens Valley Radio Observatory in Northern California for 13 years as part of a general study of blazar behavior. But this particular blazar exhibits a strange behavior: Its brightness shows regular ups and downs as predictably as the ticking of a clock.

Researchers now think this regular variation is the result of a second black hole tugging on the first as they orbit each other about every two years. Each of the two black holes in PKS 2131-021 is estimated to be a few hundred million times the mass of our Sun. To confirm the finding, scientists will try to detect gravitational waves – ripples in space – coming from the system. The first detection of gravitational waves from black hole binaries was announced in 2016.

To confirm that the oscillations weren’t random or the cause of a temporary effect around the black hole, the team had to look beyond the decade (2008 to 2019) of data from the Owens Valley Observatory. After learning that two other radio telescopes had also studied this system – the University of Michigan Radio Observatory (1980 to 2012) and the Haystack Observatory (1975 to 1983) – they dug into the additional data and found that it matched predictions for how the blazar’s brightness should change over time.

“This work is a testament to the importance of perseverance,” said Lazio. “It took 45 years of radio observations to produce this result. Small teams, at different observatories across the country, took data week in and week out, month in and month out, to make this possible.”

To learn more, read the news release from Caltech.

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Two Stars Spiraling Towards Explosive Doom Detected in Our Cosmic Neighborhood

A binary star just 1,500 light-years away is spiraling towards a spectacular doom.

HD265435 consists of a type of dead star called a white dwarf and its binary companion; they’re orbiting each other so close together, the white dwarf is slurping material from the other star. Eventually, so the theory goes, the white dwarf will gain so much mass that it is no longer stable, exploding in a tremendous supernova.

 

That won’t be for a while yet, but the discovery of such a doomed binary is a rare one, say a team of scientists led by astronomer Ingrid Pelisoli from the University of Warwick in the UK; the finding can help us better understand the processes leading up to these incredible events.

This is important, because the type of supernova this unstable star will cause is what we call a standard candle – one of the key tools we use to measure cosmic distances.

Stars spend their lives (what we call the main sequence) busily fusing elements to heavier elements in their cores, but they don’t have an endless supply. Eventually, they will run out of stuff they can fuse, and die, ejecting their outer material. Depending on the mass of the star, several things can happen at this point.

For most stars, the core will collapse into an ultradense object, and what that object is will depend on the mass of the progenitor main-sequence star. For stars over 30 times the mass of the Sun, that will be a black hole. For stars between about 8 and 30 solar masses, it will be a neutron star. And for stars below 8 solar masses (including our Sun), it will be a white dwarf.

 

These stars still shine with residual heat, and take a very, very long time to cool to darkness. The only thing that keeps them from collapsing entirely under their own gravity is electron degeneracy pressure. At a certain pressure level, electrons are stripped from their atomic nuclei. Because identical electrons can’t occupy the same space, these electrons supply the outward pressure that keeps the star intact.

That has a limit, too. Over about 1.4 times the mass of the Sun, or the Chandrasekhar limit, the white dwarf becomes so unstable that it dies again, exploding in a Type Ia supernova. This can happen when the white dwarf orbits so close to a binary companion that it siphons material from the other star, tipping it over the Chandrasekhar limit.

But there’s a curious discrepancy in the number of observed Type Ia supernova remnants, and the number of Type Ia progenitor candidates – we simply haven’t found as many progenitors as there should be, based on the number of observable remnants.

This is why HD265435 is so exciting. At its 1,500 light-year distance, it’s the closest known Type Ia progenitor, which means we have the opportunity to study it in detail.

 

“We can estimate how many supernovae are going to be in our galaxy through observing many galaxies, or through what we know from stellar evolution, and this number is consistent,” Pelisoli said.

“But if we look for objects that can become supernovae, we don’t have enough. This discovery was very useful to put an estimate of what a hot subdwarf and white dwarf binaries can contribute. It still doesn’t seem to be a lot, none of the channels we observed seems to be enough.”

The binary itself is fascinating. It consists of the white dwarf, and a hot subdwarf, the latter being a red giant after it has ejected its outer layers and is about to begin fusing helium, having run out of hydrogen. This hot subdwarf is small, just 0.6 times the mass of the Sun, but extremely bright – so bright that it completely outshines the white dwarf. We can’t see the white dwarf at all.

Pelisoli and her team identified the binary by changes in brightness in the hot subdwarf. These changes suggested that the hot subdwarf is being pulled into a teardrop shape by something massive very close to it.

By carefully analyzing the brightness changes, the researchers were able to infer what is happening. A white dwarf about the same mass as the Sun is orbiting the hot subdwarf every 100 minutes or so, close enough to be siphoning material from the subdwarf and pulling its atmosphere out of shape.

Together, the masses of the two objects exceed the Chandrasekhar limit, which means a Type Ia supernova should occur… in about 70 million years or so. Before that happens, the white subdwarf will run out of material to fuse and turn into a second white dwarf star.

This discovery could help us to understand a massive problem with cosmology. Because the Chandrasekhar mass is within a known range, Type Ia supernovae have a determinable intrinsic brightness. This means we can use them to map distances in the local Universe – but we use several methods to do this, and different methods give us different results for the expansion rate of the Universe.

“The more we understand how supernovae work, the better we can calibrate our standard candles. This is very important at the moment because there’s a discrepancy between what we get from this kind of standard candle, and what we get through other methods,” Pelisoli said.

“The more we understand about how supernovae form, the better we can understand whether this discrepancy we are seeing is because of new physics that we’re unaware of and not taking into account, or simply because we’re underestimating the uncertainties in those distances.”

The research has been published in Nature Astronomy.

 

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