News Feeds

The thing about exoplanets is that astronomers don’t see them the way most people think they do. Part of the reason for that is the way we announce them. Whenever an interesting exoplanet is discovered, the press release usually has colorful artwork showing oceans, mountains, and clouds. Something visually captivating like the image above. But the reality is that we have only imaged a few exoplanets directly, and even then, they appear only as small fuzzy blobs. Most of the known exoplanets were discovered by the transit method, where the star dims slightly as the planet passes in front of it. So what astronomers actually see is a periodic flickering of starlight.

This isn’t a problem for astronomers, since they are interested in data, not pretty pictures. Usually, the data is strong enough to confirm the presence of an exoplanet without directly observing it. But sometimes the observational data can be a bit more fuzzy, and that means we might think a planet is there only for further observations to prove us wrong. So sometimes an exoplanet is announced, only for the discovery to be retracted later. But sometimes a planet is confirmed, then unconfirmed, then confirmed again, as in the case of a recent study of Barnard’s star.

Barnard’s star is a small red dwarf just 6 light-years from Earth. Back in 2018, observations of the star suggested the presence of a Super-Earth sized companion named Barnard b. What’s interesting about this exoplanet is that it wasn’t discovered by the usual transit method but by a different approach known as the radial velocity method. As a planet orbits a star, the gravitational pull of the planet causes the star to wobble slightly toward and away from us. Since the relative motion of the star can cause its spectrum to shift slightly, we can observe the shift to know if the planet is there. But the radial velocity method is more difficult to do than the transit method, which is part of the reason fewer exoplanets have been discovered this way. And in this particular case, the data was fairly tenuous, and so Barnard b was shifted to the unconfirmed category.

Diagram detailing the Radial Velocity method. Credit: Las Cumbres Observatory

This new study finds that the 2018 discovery was a false positive. The data doesn’t support the existence of a super-Earth orbiting Barnard’s star. But the data does confirm the presence of an exoplanet. Barnard b does exist, just not the one we thought. This newly confirmed planet isn’t a super-Earth, but rather has less mass than our world. It orbits the star every 3 days, which is part of the reason it was so difficult to detect.

It took 5 years of observational data to confirm this exoplanet, which just reinforces how difficult it is to find planets this way. But the good news is that the data hints at the presence of other planets as well. It will take more data and study to confirm them, but it’s quite possible that Barnard’s star has a whole system of small worlds, similar to the TRAPPIST-1 system.

Reference: J. I. González Hernández, et al. “A sub-Earth-mass planet orbiting Barnard’s star.” Astronomy & Astrophysics 690 (2024): A79.

Reference: Ribas, Ignasi, et al. “A candidate super-Earth planet orbiting near the snow line of Barnard’s star.” Nature 563.7731 (2018): 365-368.

The post Bernard's Star Has a Planet (Again)! appeared first on Universe Today.

'Future You' is a generative AI tool that enables users to have a simulated conversation with a potential version of their future selves. The chatbot is meant to reduce users' anxiety, improve positive emotions, and guide them toward making better everyday choices.

Researchers have developed a solid electrolyte that could be a suitable material for all-solid-state batteries. Solid electrolyte composed of nanoparticles embedded in an amorphous matrix shows high conductivity, formability, and electrochemical stability.

Scientists have developed a new method to simulate the complex movements of animals with exceptional accuracy. The research team set out to solve a long-standing challenge in biology -- how to accurately model the intricate and seemingly unpredictable movements of living organisms. They focused on the nematode worm Caenorhabditis elegans, a model organism widely used in biological research. The findings help predict and understand animal behavior, with potential applications ranging from robotics to medical research.

Researchers have created an array of nanopillars that can breach the nucleus of a cell -- the compartment that houses our DNA -- without damaging the cell's outer membrane. This new 'gateway into the nucleus' could open new possibilities in gene therapy, where genetic material needs to be delivered directly into the nucleus, as well as drug delivery and other forms of precision medicine.

Simple encapsulation by terpene-based chiral capsules allows various non-chiral organic dyes to display chiroptical properties in water, without requiring elaborate chemical modifications, scientists report. The present molecular tools could pave the way to advanced optical technologies, spanning the fields of digital storage, biomedicine, and catalysis, to name a few.

People with diabetes take insulin to lower high blood sugar. However, if glucose levels plunge too low -- from taking too much insulin or not eating enough sugar -- people can experience hypoglycemia, which can lead to dizziness, cognitive impairment, seizures or comas. To prevent and treat this condition, researchers report encapsulating the hormone glucagon. In mouse trials, the nanocapsules activated when blood sugar levels dropped dangerously low and quickly restored glucose levels.

It's important to eat your veggies, but some essential vitamins and nutrients can only be found in animals, including certain amino acids and peptides. But, in a proof-of-concept study, researchers developed a method to produce creatine, carnosine and taurine -- all animal-based nutrients and common workout supplements -- right inside a plant. The system allows for different synthetic modules to be easily stacked together to boost production.

The compound creatine, a popular exercise supplement that only occurs naturally in animal products, could one day be produced in edible plants

Today we’re back to new strips as the artist has returned from hols. In the latest Jesus and Mo strip, called “coincidence,” Mo (in bed with Jesus) draws the common but false distinction between anti-semites and anti-Zionists.

Reader Chris Taylor continue his voyage to Queensland with Part 3 of his narrative (see links to other parts here).  Chris’s captions are indented, and you can enlarge the photos by clicking on them:

In this part I will show some more of the Yourka landscape and then give some insight into the work involved in restoring the landscape.

Downstream from the accommodation, Sunday Creek is crossed by the Glen Ruth Road. Just by the crossing there is a series of small pools where the water runs beneath a shady canopy of Paperbarks, Melaleuca quinquinervia:

and gum trees, probably Eucalyptus tereticornis:

It was a nice and cool place to sit, next to the creek in these areas.

There were more dragonflies here. This is a Scarlet Percher, Diplacodes haematodes. These are common throughout Australia. Fairly small in size (wingspan about 60mm), they make up for it with their brilliant red coloration:

This one even let me take a portrait too!

Driving back to the accommodation at Sunday Camp, we came across this Agile Wallaby Notamacropus agilis, a species that is found across the northernmost parts of Australia, and into southern New Guinea. This is a robust male, probably 80cm tall, with a tail about the same length.  The females of this species are rather smaller. These are quite common across the reserve:

Next to the road was this tall Lemon Scented Gum, Corymbia citriodora, shining in the late afternoon light as the moon rises behind it. This is an area where the Heathy Woodlands are coming back nicely with plenty of recruitment of young plants:

Returning the reserve to something like its former state is not as easy as just letting nature take its own course. There is a lot of time and effort invested in the process. Bush Heritage Australia have a program where volunteers can apply to do some of this work. There are fences to be removed to allow for free passage of the native animals, there are introduced weeds to be eradicated, and exotic animals to be controlled, and on these some reserves fire management to be considered.

Yourka used to be a cattle station. Bush Heritage no longer have cattle on the property, but Yourka being surrounded by other cattle farms, incursions are common. We came across a small mob of these as we drove out to work near the Herbert River. These are probably the Droughtmaster breed:

The Herbert River forms part of the western boundary of Yourka:

Here it runs between steep banks as much as 8m high:

We were there in the dry season. In the wet season, the river will often run bank high – or even spread out onto the flood plain. In December 2023, this region was affected by Tropical Cyclone Jasper. The storm stalled as it came onto the coast, inundating the area from Cooktown in the north to Innisfail in the south as well as parts of the interior. The city of Cairns received 2200mm of rain in 4 days. Yourka would have had much less, but even so the Herbert breached its banks. We found flood damage and debris at least 12m above the creek beds.

Flooding causes a lot of damage, as the volume of water and the vegetation it carries will lay flat -or carry away – any fence. To mitigate this problem some of the creeks are fitted with Flood Fencing.

These are made from sheets of corrugated iron suspended from a wire rope. In the dry season these will stop most cattle from wandering on to the reserve, while allowing other native animals to pass beneath. In the wet season, the pressure of the water flow will just push the panels up and allow the debris to pass without sustaining too much damage.

But in exceptional flows even these fences are just ripped out and tangled and the metal sheets torn and destroyed.

We came to the reserve to work, and one of our jobs turned out to be repairing some of the flood fencing! We are putting the final touches to a fence that crosses Sunday Creek for about 70m and up the banks that are 11m high.

While collecting the materials for the fencing from the stockpile, there is a technique to lifting the metal sheets; I always lift from the far side, so that the metal remains between me and anything that has been hiding underneath.

Sure enough, one of the times that I lifted a metal sheet, beneath it was a snake. In this case it was nonvenomous, but it did reinforce the need to do the right thing – especially when on such a remote reserve!

Spotted Python, Antaresia maculosa. This is quite a small snake, less than 1m long, but this species does not grow much bigger.

Just recently, in casual conversation, someone commented to me that “they” already have a cure for cancer but are hiding it. This is a claim I frequently encounter. One survey, from 2005, found that 27.3% of those surveyed endorsed this belief. Another survey from 2014 found that 37% of people believe the FDA is suppressing natural cancer cures on behalf of “Big […]

The post Conspiracy Thinking And Alternative Medicine first appeared on Science-Based Medicine.

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