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In about five billion years, our Sun will exit its main sequence phase and transition to its red giant phase. At this point, the Sun will expand and consume the planets of the inner Solar System, including Mercury and Venus. What will become of Earth when this happens has been the subject of debate for many decades. But with the recent explosion in exoplanet discoveries, 5,759 confirmed in 4,305 systems so far, astronomers hope to learn more about how planets fare as their stars near the end of their life cycle.

Using the 10-meter telescope at the Keck Observatory in Hawaii, an international team of astronomers discovered an Earth-like planet orbiting a white dwarf star 4,000 light-years from Earth. This planet orbits its star, about half the mass of our Sun, at a distance roughly twice that of the Earth today. The system resembles what is expected to become of our system once the Sun has exhausted the last of its fuel and blows off its outer layers in a supernova. It also offers some assurances that Earth will survive the Sun becoming a red giant and exploding in a supernova.

The team was led by Keming Zhang, a former doctoral student at the University of California, Berkeley, who is now an Eric and Wendy Schmidt AI in Science Postdoctoral fellow at UC San Diego. He was joined by multiple colleagues from UC Berkeley, UC San Diego, Tsinghua University, the Harvard & Smithsonian Center for Astrophysics (CfA), the California Institute of Technology (Caltech), the University of Washington, Ohio State University, the University of Maryland, and the NASA Goddard Space Flight Center. The paper that details their findings recently appeared in the journal Nature Astronomy.

To break it down, the Sun’s expansion as it becomes a red giant will likely mean the destruction of Mercury and Venus. At the same time, the Sun’s decreasing mass will force the surviving planets to migrate to more distant orbits, which could include Earth. If Earth survives when the Sun finally goes supernova, it will probably end up orbiting the resulting white dwarf remnant at a distance of 2 astronomical units (AUs) – twice its current distance. As Zhang related in a UC Berkeley News release,

“We do not currently have a consensus whether Earth could avoid being engulfed by the red giant sun in 6 billion years. In any case, planet Earth will only be habitable for around another billion years, at which point Earth’s oceans would be vaporized by runaway greenhouse effect — long before the risk of getting swallowed by the red giant.”

This is what astronomers may have found when they observed this planetary system roughly 4,000 light-years away. Located near the bulge at the center of our galaxy, this system was first noticed in 2020 when it passed in front of another star located 25,000 light-years from Earth. This caused a microlensing event, where the powerful gravity of the white dwarf focused and amplified the light of the background star by a factor of 1,000. The event was first detected by the Korea Microlensing Telescope Network (NMTNet) in the Southern Hemisphere, leading the team to designate it KMT-2020-BLG-0414.

The team estimated that the system included a star about half the mass of our Sun, an Earth-sized planet, and a likely brown dwarf with 17 times the mass of Jupiter. The analysis also concluded that the Earth-sized planet orbited its star at a distance of between 1 and 2 AUs. At the time, it was difficult to identify the type of star because neighboring stars and the magnified background star obscured its light. By 2023, the lensing event had passed, which made it possible for the team to examine the lensing system more closely using the Keck II 10-meter telescope in Hawaii.

As Zhang indicated, the team took two separate images but detected nothing. Since the lensing star was dark and low mass, they concluded it could only be a white dwarf. As noted, scientists are unsure what will happen to Earth when it reaches its red giant phase or if it will survive to orbit the white star remnant. This planetary system provides an example of a planet that did survive its sun expanding and exploding in a supernova. However, there is little chance of it being habitable since it orbits beyond the white dwarf’s habitable zone.

The top of Mauna Kea is a prime site for telescopes, as shown in this image. It boasts clear, dry atmospheric conditions. Global climate change could alter that. Credit: Mauna Kea Observatories

What’s more, some research suggests that if the expanding Sun doesn’t engulf our planet, it will eventually blow our atmosphere off and vaporize Earth’s oceans. Said co-author Jessica Lu, an associate professor and chair of astronomy at UC Berkeley:

“Whether life can survive on Earth through that (red giant) period is unknown. But certainly the most important thing is that Earth isn’t swallowed by the Sun when it becomes a red giant. This system that Keming’s found is an example of a planet — probably an Earth-like planet originally on a similar orbit to Earth — that survived its host star’s red giant phase.”

In addition, Zhang and his colleagues resolved an ambiguity regarding the location of the brown dwarf. According to the original analysis, the brown dwarf had a very wide Neptune-like or Mercury-type orbit. In the latter case, this would make it a hot brown dwarf, similar to the many “Hot Jupiters” observed repeatedly beyond our Solar System. Zhang and his colleagues could rule the latter scenario since a closely-orbited brown dwarf would have been consumed once the star entered its red giant phase.

This ambiguity resulted from “microlensing degeneracy,” where two distinct lensing configurations can give rise to the same lensing effect. Luckily, Zhang and co-author Bloom discovered a similar degeneracy in 2022 using a machine-learning algorithm designed to analyze microlensing simulations. When they applied the same technique to KMT-2020-BLG-0414, they were able to rule out alternative models of the planetary system. As Bloom explained:

“Microlensing has turned into a very interesting way of studying other star systems that can’t be observed and detected by the conventional means, i.e. the transit method or the radial velocity method. There is a whole set of worlds that are now opening up to us through the microlensing channel, and what’s exciting is that we’re on the precipice of finding exotic configurations like this.”

A NASA illustration of the giant planet WASP-193b and its star. Credit: NASA/ESA/CSA)

This system offers many opportunities for follow-up observations by next-generation telescopes like the Nancy Grace Roman Space Telescope (RST), scheduled for launch in 2027. One of the main objectives of the RST is to measure light curves from microlensing events to find exoplanets. “What is required is careful follow-up with the world’s best facilities, i.e., adaptive optics and the Keck Observatory, not just a day or a month later, but many, many years into the future, after the lens has moved away from the background star so you can start disambiguating what you’re seeing,” said Bloom.

The findings would seem to confirm another theory about the fate of our Solar System. When the Sun expands, our system’s habitable zone will migrate to the outer Solar System. If humanity is still around at this time, it will need to migrate to the icy satellites that orbit Jupiter and Saturn, which are likely to become planets covered in deep oceans – giving new meaning to the words “Ocean Worlds.”

Further Reading: Berkeley News, Nature Astronomy

The post An Earth-like Planet Around a Dead Sun Provides Some Reassurance About the Future of Earth appeared first on Universe Today.

Why is it important to search for exoplanets in triple star systems and how many can we find there? This is what a recent study accepted by Astrophysics & Space Science hopes to address as a pair of researchers from the University of Texas at Arlington investigated the statistical likelihood of triple star systems hosting exoplanets. This study holds the potential to help researchers better understand the formation and evolution of triple star systems and whether they are suitable to find life as we know it.

Here, Universe Today discusses this incredible research with Dr. Manfred Cuntz, who is a physics professor at the University of Texas at Arlington and lead author of the study, regarding the motivation behind the study, the most significant results, the importance of studying triple star systems, and the likelihood of finding exolife in triple star systems. Therefore, what was the motivation behind the study?

Dr. Cuntz tells Universe Today, “Ages and metallicity (i.e., the amount of heavy elements = elements other than hydrogen and helium) are fundamental properties of stars – a statement that applies to all stars. Considering that most stars (which however does not apply to the sun) are members of higher order systems – the study of stars in triple stellar systems is a natural extension of research focusing on single stars.”

For the study, the researchers conducted a statistical analysis regarding both the ages and metallicities of triple star systems with a total of 27 confirmed exoplanets based on past research, with the number of exoplanets in each system ranging from 1 to 5. The ages of the triple star system ages, with margins of error, ranged between 20 million years old to 7.2 billion years old. For context, our Sun is estimated to be slightly more than 4.6 billion years old.

The metallicities of the star systems, with margins of error, ranged between -0.59 to +0.56, which is often calculated based on the ratio of iron to hydrogen (Fe/H), and is also calculated with the equation X + Y + Z =1, with X being the fraction of hydrogen, Y being the fraction of helium, and Z being everything else (i.e., carbon, oxygen, silicon, iron, etc.). These values range between -4.5 to +1.0, with stars exhibiting 0, -1, greater than 0, and less than 0 indicating a star is equal in iron abundance to our Sun, one-tenth the iron abundance of our Sun, greater metal content than our Sun, and less metal content than our Sun, respectively. Therefore, what were the most significant results from this study?

“Two highly significant results have been identified,” Dr. Cuntz tells Universe Today. “First, stars in triple stellar systems are on average notably younger than stars situated in the solar neighborhood. The most plausible explanation is a possible double selection effect due to the relatively high mass of planet-hosting stars of those systems (which spend less time on the main-sequence than low-mass stars) and that planets in triple stellar systems may be long-term orbitally unstable. The stellar metallicities of those stars are on average solar-like; however, owing to the limited number of data, this result is not inconsistent with the previous finding that stars with planets tend to be metal-rich as the deduced metallicity distribution is relatively broad.”

The distances to the respective triple star systems range between 4.3 to 1,870 light-years from Earth, but only 6 of the 27 triple star systems reside within 100 light-years away. These six triple star systems include Alpha Centauri (4.3 light-years), Epsilon Indi (11.9 light-years), LTT 1445 (22.4 light-years), Gliese 667 (23.6 light-years), 94 Ceti (73.6 light-years), and Psi1 Draconis (74.5 light-years), with the number of total exoplanets (with exoplanet candidates) within each system being 3 (2), 1, 1, 2 (1), 1, and 1, respectively. For context, as of September 2024, the total number of confirmed exoplanetary systems within our cosmos is more than 4,300 that encompasses almost 5,800 exoplanets. But despite the small number of triple star systems that host exoplanets, what is the importance of studying triple star systems?

Dr. Cuntz tells Universe Today, “Most stars (which however does not apply to the sun) are members of higher order systems, especially binaries – and in less common cases triple stellar systems, and systems of even higher order. Therefore, the study of planets hosted by triple stellar systems is a natural extension of the standard approach focusing on planets around single stars. The current study focuses on some of the properties of stars in triple stellar systems, which are also known to host (a) planet(s) – a relatively rare setting. The importance of the current study is to expand our general understanding of star-planet systems.”

For Alpha Centauri, the exoplanet, Proxima Centauri b, has been confirmed to be terrestrial (rocky), approximately the size of Earth in both radius and mass, and orbits within the habitable zone (HZ) of Proxima Centauri, one of the stars that comprise the Alpha Centauri triple star system. The only other terrestrial exoplanet orbiting within its star’s HZ is Gliese 667 Cc, whose mass and radius is larger than the Earth, designating it as a super-Earth. Therefore, given the small number of triple star systems that have exoplanets and even fewer that host terrestrial exoplanets orbiting in its HZ, what is the likelihood of finding exolife in triple star systems?

“The only planet where we know for sure that life does exist is Earth,” Dr. Cuntz tells Universe Today. “However, through both observational and theoretical studies during many decades of committed work, scientists are convinced that exolife is almost certainly real. This statement should also apply to planets in triple star systems. However, those planets are typically subject to relatively variable environmental forcings (e.g., variable amounts of radiation received by the stellar components), which is expected to reduce the likelihood of advanced life forms, but should still permit microbial life, especially extremophiles.”

As the number of confirmed exoplanets continues to grow, so should the confirmed number of triple star systems that host exoplanets, as well. When science fiction fans read about multi-star systems, they almost immediately think of the iconic scene in Star Wars: A New Hope of Luke Skywalker watching two stars setting on the horizon. While Tatooine was habitable for humans and other interesting life forms, this might not be the case in the real world, as demonstrated by Proxima Centauri b currently being the only Earth-like exoplanet orbiting in its HZ within 100 light-years from Earth. Therefore, what constraints should scientists put on finding life in triple star systems? Should we instead study their moons, as the film Avatar depicted the semi-habitable moon, Pandora, orbiting a much larger exoplanet within the Alpha Centauri system? Are triple star systems with exoplanets as rare as the statistics show today?

“The search for life outside of planet Earth continues to be a fascinating topic,” Dr. Cuntz tells Universe Today. “Political and societal support for ongoing and future space missions is highly appreciated. We, as scientists, are grateful about the ongoing support by the taxpayers around the world, but especially here in the U.S.”

What new discoveries about triple star systems will researchers make in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

Reference: Cuntz, Manfred & Patel, Shaan D. “On the Age and Metallicity of Planet-hosting Triple Star Systems.” Astrophysics and Space Science (2024) (accepted)

The post We Don’t See Many Planets in Old Triple Star Systems appeared first on Universe Today.

Rosh Hashanah, the Jewish New Year (the new year is 5785) starts tomorrow evening and ends Friday evening. The local Hillel, in its generosity, offered faculty and staff a New Year gift basket, containing several items traditionally associated with this holiday, like apples and honey.

But the large cloth bag, which I picked up on my way home, was full of goodies:

Two round challah
3 apples
a small jar of honey
a honey dipping stick
THREE boxes of matzoh ball soup mix
and three erasers,

all shown below. (I love challah!) It was a bracing relief fron the tensions of the afternoon when I watched Iranian missiles land on Israeli soil. Fortunately, only one person seems to have been killed, ironically a Palestinian from Gaza who was cut down on the West Bank by a missile.

Maybe I am not a good enough Jew, but I do not get what the erasers are for. I am sure a reader will instruct me; my guess is that it is to erase the bad things from last year.

שנה טובה  (shanah tova)!

 

Clinical study of microscope-integrated system lays groundwork for using OCT to define tumor margins and reveal subsurface brain anatomy.

The genome inside each of our cells is modelled by tension and torsion -- due in part to the activity of proteins that compact, loop, wrap and untwist DNA -- but scientists know little about how those forces affect the transcription of genes. Transcription of a gene begins when RNAP binds to a 'promoter' DNA sequence and ends at a 'terminator' sequence where the mRNA copy is released. The canonical view of termination holds that after releasing the mRNA, RNAP dissociates from the DNA. A team of researchers has demonstrated how force plays a role in an alternative to canonical termination.

Are there planets beyond Earth where humans can live? The answer is maybe, according to physicists examining F-type star systems.

Some proteins in the human body are easy to block with a drug; they have an obvious spot in their structure where a drug can fit, like a key in a lock. But other proteins are more difficult to target, with no clear drug-binding sites. To design a drug that blocks a cancer-related protein, scientists took a hint from the protein's paralog, or 'twin.' Using innovative chemical biology methods, the scientists pinpointed a druggable site on the paralog, and then used that knowledge to characterize drugs that bound to a similar -- but more difficult to detect -- spot on its twin. Ultimately, they found drugs that only bound to the protein of interest and not its highly similar sibling.

People report greater life satisfaction six months after starting Parkrun events, which could partly be due to the supportive environment

Researchers developed a technique guaranteeing that data remain secure during multiparty, cloud-based computation. This method, which leverages the quantum properties of light, could enable organizations like hospitals or financial companies to use deep learning to securely analyze confidential patient or customer data.

Researchers developed a technique guaranteeing that data remain secure during multiparty, cloud-based computation. This method, which leverages the quantum properties of light, could enable organizations like hospitals or financial companies to use deep learning to securely analyze confidential patient or customer data.

A new study has measured the toxicity of several types of per- and polyfluoroalkyl substances (PFAS), better known as 'forever chemicals,' when mixed together in the environment and in the human body.

The Big Conflict has begun, though I hope it’s a limited attack.  Iran has launched at least 150 ballistic missiles at Israel, and many appear to be landing,  but the U.S. has vowed to provide assistance. This will doubtlessly be assistance in defense (like the last attack from Iran), for I can’t imagine the U.S. launching its own weapons at Iran.  Unfortunately, there are reports that some of the missiles have evaded Israel’s “Arrow” defense system against ballistic missiles and may be landing in Tel Aviv and Jerusalem. There may be dozens of hits. and apparently every city in Israel is under attack.

Israel will respond; there is no doubt of that.

And people just can’t stop attacking the Jewish state.

Here’s a real-time video, with commentary (h/t Debra):

https://traffic.libsyn.com/secure/sciencesalon/mss473_Max_Boot_2024_10_01.mp3 Download MP3

From best-selling biographer Max Boot comes this revelatory portrait, a decade in the making, of the actor-turned-politician whose telegenic leadership ushered in a transformative conservative era in American politics. Despite his fame as a Hollywood star and television host, Reagan remained a man of profound contradictions, even to those closest to him. Never resorting to either hagiography or hit job, Reagan: His Life and Legend charts his epic journey from Depression-era America to “Morning in America.” Providing fresh insight into “trickle-down economics,” the Cold War’s end, the Iran-Contra affair, and so much more, this definitive biography is as compelling a presidential biography as any in recent decades.

Max Boot is a Russia-born naturalized American historian and foreign-policy analyst and a senior fellow for national security studies at the Council on Foreign Relations. He has worked as a writer and editor at the Wall Street Journal, The New York Times, the Los Angeles Times, The Weekly Standard, and the Christian Science Monitor, and is now a regular columnist for the Washington Post. His New York Times bestseller, The Road Not Taken: Edward Lansdale and the American Tragedy in Vietnam, was a finalist for the Pulitzer Prize in Biography. He is also the author of The Savage Wars of Peace: Small Wars and the Rise of American Power, War Made New: Technology, Warfare, and the Course of History: 1500 to Today, Invisible Armies: An Epic History of Guerrilla Warfare from Ancient Times to the Present, and, controversially, of The Corrosion of Conservatism: Why I Left the Right. His new book is Reagan: His Life and Legend.

Shermer and Boot discuss:

• What led him to undertake this biography
• How to write a biography—with sources, and which to consider as reliable
• Early influences on Reagan’s life: family, Midwestern upbringing, education, teachers, mentors, experiences.
• Relative influence of genes, environment, and luck.
• The Lifeguard
• Depression economics influences
• Reagan’s attitudes and beliefs on social issues reflecting those of his generation
• Radio and Acting
• President of the Screen Actor’s Guild and his purported role in preventing a Communist takeover of Hollywood.
• GE pitch man
• A groundbreaking look at why Reagan left the Democratic Party, showing his reliance on conspiracy-mongering tracts, fake quotes, and statistics—and the influence of both the FBI and General Electric.
• Revelations about the role of “white backlash” politics in Reagan’s rise.
• California governor
• 1968 Presidential campaign
• 1976 Presidential campaign
• Goldwater and the state of the Republican Party when Reagan entered politics
• New evidence about the “October Surprise” and the involvement of Reagan’s aides in political skullduggery prior to the 1980 election
• Arthur Laffer and Trickledown economics
• Budget deficit
• AIDS epidemic
• Iran-Contra
• Abortion
• “Evil Empire”
• Gorbachev Geneva summit
• Gorbachev Reykjavik summit
• Strategic Defense Initiative (SDI/Star Wars)
• Reagan on nuclear weapons
• Rancho del Cielo
• An examination of how Reagan was both different from—and similar to—Donald Trump
• Hotspots: N Korea, Iran, Israel, China.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

Discerning whether a nuclear reactor is being used to also create material for nuclear weapons is difficult, but capturing and analyzing antimatter particles has shown promise for monitoring what specific nuclear reactor operations are occurring, even from hundreds of miles away. Researchers have developed a detector that exploits Cherenkov radiation, sensing antineutrinos and characterizing their energy profiles from miles away as a way of monitoring activity at nuclear reactors. They proposed to assemble their device in northeast England and detect antineutrinos from reactors from all over the U.K. as well as in northern France.

Because this is a contest for computer geeks, banning Israeli students is particularly onerous, as they’d done excellently in the past.  As the article below notes, “In the 2024 competition, held in Alexandria, Egypt, four Israeli students participated remotely due to security concerns and won three gold medals and a bronze. The Israeli team placed second overall out of 94 participating countries and more than 350 student competitors.”

But now there’s no chance for Israeli medals because of the ban. And that ban serves no purpose I can see save to further demonize Israel by hurting its young people, and to demonstrate some kind of twisted “virtue” on the part of the organizers.

Now that the American Association of University Professors has dropped its long-standing opposition to academic boycotts (undoubtedly to give the okay to boycotts of Israel, though they won’t say it), others are following suit. A new article in Tablet gives examples of how Jews are being “frozen out” of not just academia, but publishing—and this is largely in America! A wave of anti-semitism is sweeping the world, and it’s not good.

The Times of Israel reports on the latest instance of Jew-banning, and also shows the resilience of those banned young Jews.  Click to read.

Excerpts:

Israel won’t be allowed to participate as a competing nation in the 2025 International Olympiad in Informatics (IOI), a prestigious international competition for high school students, in the first such decision by a global tournament organizer.

The IOI General Assembly voted by a two-thirds majority to “sanction Israel for its role” in the ongoing “humanitarian crisis in Gaza caused by the ongoing conflict,” according to a Tuesday announcement by the IOI.

“Beginning in 2025, Israel will not be recognized as a participating delegation at IOI, but four contestants from Israel may still participate under the IOI flag,” the statement said.

Well isn’t that alternative special? Happily, the Israelis aren’t having it:

Today, the Education Ministry says that Israeli students competing in the olympiad under the IOI flag is “not going to happen.”

“The Israeli team will carry the Israeli flag proudly on the way to many more victories and international achievements… The ministry is examining, in cooperation with the Foreign Ministry, decisive measures on the issue,” the statement says.

The punishment is levied because of the conflict in Gaza. The IOI website says this:

Dear Colleagues and members of the IOI community,

This message is being sent to provide an update on a significant decision of the General Assembly of the IOI.

Members of the community requested that the IOI respond to the humanitarian crisis in Gaza caused by the ongoing conflict. During IOI 2024, the General Assembly debated many options at length. The question about what action to take, if any, was not taken lightly. The result was a vote to sanction Israel for its role in the crisis. Over two thirds of the delegations voted in favour of this action. Specifically, the action means that beginning in 2025, Israel will not be recognized as a participating delegation at IOI, but four contestants from Israel may still participate under the IOI flag.

There will continue to be reflection and debate about the mission of the IOI and its connection to war and other international disputes.Assoc/Prof Sun Teck Tan
President of IOI

Perhaps the IOI should be ideologically neutral instead of taking sides. But if they must take sides, they’re taking the wrong one.

Note that the IOI is sanctioning Israel for its “role in the crisis”, which means for defending itself (Israel isn’t allowed to win a war). If the IOI is doing this because “too many Gazan civilians were killed”, they should realize that “civilians” as reported by the Hamas-controlled Gazan Health Ministry include Hamas terrorists; that Hamas elevated civilian deaths as part of its strategy because dead Gazans mean more world opprobrium towards Israel; and that civilian deaths were elevated because Hamas deliberately embedded itself in civilian areas, schools, and hospitals. Further, the ratio of civilians killed to Hamas fighters killed is among the lowest in the history of modern warfare (it’s getting tiresome to repeat this). And I haven’t even mentioned the hostages. . . .  This isn’t computer science, after all, but simple facts.

If anybody is banned from this competition, it should be Palestine, home of terrorists, genocidal towards Jews, and the territory that started the war. Remember, they’re punishing young Jews that had nothing to do with the war, so, under that philosophy, if anybody should be punished, it should Palestinians. But perhaps they shouldn’t mix politics with computers at all.

The next IOI competition, sans Israelis, is scheduled to be held in Bolivia next year.

Cracks running through samples of asteroid Ryugu were probably formed by the repeated thawing and freezing of water inside it, which could have helped asteroids like this carry the building blocks of life to early Earth

Understanding the “effort paradox” can help you reshape your relationship to exertion so that you commit to those hard but truly meaningful activities

Researchers have synthesized a new compound, which forms a so-called covalent organic framework. The compound, which is based on condensed phosphonic acids, is stable and can for example be used to capture carbon dioxide.

Osaka Metropolitan University researchers compared the diagnostic performance of ChatGPT and radiologists in assessing 150 brain tumor MRI reports. Their findings might surprise you.

Everyday experience tells us that light reflected from a perfectly flat mirror will give us the correct image without any deformation. Interestingly, this is not the case when the light field itself is structured in a complex way. Tiny deformations appear. These have now been observed in the laboratory. The results confirm the prediction of this fundamental optical effect made more than a decade ago. They also show how it can be used, for example, as a method for determining material properties.