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Dyson Spheres have been a tantalising digression in the hunt for alien intelligence. Just recently seven stars have been identified as potential candidates with most of their radiation given off in the infrared wavelengths. Potentially this is the signature of heat from a matrix of spacecraft around the star but alas, a new paper has another slightly less exciting explanation; dust obscured galaxies. 

There are a number of ways to hunt for aliens and one of them is to look for signs of large scale projects in space. Enter the Dyson Sphere. The idea was first proposed by Freeman Dyson in 1960 to describe that an advanced civilisations would position power collectors and even habitats around a star to harness its power. Eventually such infrastructure would likely surround the entire star and Dyson reasoned that a signature would be detectable such as an excess of infrared radiation. 

A Type II civilization is one that can directly harvest the energy of its star using a Dyson Sphere or something similar. Credit: Fraser Cain (with Midjourney)

The findings of Project Hephaistos revealed the seven M type stars from a sample of 5 million stars detected by Gaia. The astrometric satellite has been used to map stars in the Milky Way and has been of profound benefit to many pieces of research. Data from 2MASS (the Two Micron All Sky Survey) and WISE (the Wide Field Infrared Survey Explorer) were also used to identify the stars that seemed to display the expected Infrared excess. 

Artist’s impression of the Gaia spacecraft detecting artificial signals from a distant star system. In this synchronization scheme, the star system’s inhabitants send the signal shortly after witnessing a supernova, which is also seen by telescopes on Earth. (Credit: Danielle Futselaar / Breakthrough Listen)

In the recent paper by lead author Tongtian Ren and team, they explore the findings of the project and delve into the possible nature of the candidate spheres. The team cross-matched the information from data from the Very Large Array Sky Survey (VLASS) and several other radio surveys of the sky. They searched for radio sources within a radius of 10 arc seconds of the Gaia positions of the candidates. Note that the full Moon is 1,860 arc seconds across. 

Radio sources were found for three of the candidates, those named A, B and G. The accuracy of the sources was within 4.9, 0.4 and 5 arc seconds respectively and candidate G was found in multiple radio surveys. The conclusion from the team is that the seven stars are less likely to be Dyson Spheres but instead some sort of extra galactic phenomenon. The most likely explanation is a distant galaxy obscured by dust! The presence of the dust would contaminate the Infrared energy distribution in the spectra of the two objects. The other candidate, candidate B is also thought to be a distant galaxy but one that was within very close line of sight of an M type dwarf star. 

Very similar to candidates A and B, candidate G has a spectrum that reveals a radio loud active galactic nuclei with superluminal jets extending out. It is likely that galaxies are distant quasars which emit enormous amounts of radiation, but the obscuring hot dust clouds obscure most radiation, except infrared. 

What of the other four candidates? To date, no matching radio source has been found. That does not mean the hot, dust obscured galaxy model is not an adequate explanation but just that possible higher resolution radio surveys are required. Of course it may also be that they really are spheres of technology around distant stars. As much as I would love that to be true, there is no evidence for this yet. 

Source : Background Contamination of the Project Hephaistos Dyson Spheres Candidates

The post There’s Another, More Boring Explanation for those Dyson Sphere Candidate Stars appeared first on Universe Today.

The lifecycle of a star is regularly articulated as formation taking place inside vast clouds of gas and dust and then ending either as a planetary nebula or supernova explosion. In the last 70 years however, there seems to be a number of massive stars that are just disappearing! According to stellar evolution models, they should be exploding as supernova but instead, they just seem to vanish. A team of researchers have studied the behaviour of star VFTS 243 – a main sequence star with a black hole companion – and now believe it, like the others, have just collapsed, imploding into a black hole!

During the life of a star, the inward pulling force of gravity is balanced by the outward pushing thermonuclear force (the result of fusion in the core.) Once the core is rich in iron, as happens with massive stars about 8 times more massive than the Sun, the fusion process ceases as does the thermonuclear force. With the cessation of the force, the core collapses, the outer layers collapse in on the core and bounce back out as a massive explosion known as a supernova. The actual mechanism of the explosion and the formation of the compact object that is left behind from the core is still the subject of a lot of debate. 

The supernova process is one of the most powerful explosions in the universe. As the star collapses, a shockwave is produced that can create fusion in the outer shell of the progenitor star. The reactions can create new elements heavier than iron. In a paper recently published by an international team of astronomers led by Alejandro Vigna-Gómez from the Max Planck Institute for Astrophysics in Germany the team shed new light on the process. They showed that it is possible for a star to be so massive that its gargantuan force of gravity can be strong enough that even the supernova explosion is not able to take place.

The Fred Lawrence Whipple Observatory’s 48-inch telescope captured this visible-light image of the Pinwheel galaxy (Messier 101) in June 2023. The location of supernova 2023ixf is circled. The observatory, located on Mount Hopkins in Arizona, is operated by the Center for Astrophysics | Harvard & Smithsonian. Hiramatsu et al. 2023/Sebastian Gomez (STScI)

The team’s discovery seems to be linked to the concept of disappearing stars. Over the last few years, it has become evident that some stars seem to just vanish from view, neither passing through the planetary nebula phase nor going supernova. The discovery of supermassive stars undergoing complete collapse without supernova now provides a good explanation for the phenomenon. 

The team reached their conclusion when they explored an object known as VFTS 243; a binary system which includes a star thought to be 25 times more massive than the Sun and a blackhole 10 times more massive than the Sun. Both objects orbit a common centre of gravity over a period of 10.4 days and lie in the Tarantula Nebula in the Large Magellanic Cloud – 160,000 light years away. The binary system is not the first of its kind to be discovered, such systems have been known about for decades. 

30 Doradus, also known as the Tarantula Nebula, is a region in the Large Magellanic Cloud. Streamlines show the magnetic field morphology from SOFIA HAWC+ polarization maps. These are superimposed on a composite image captured by the European Southern Observatory’s Very Large Telescope and the Visible and Infrared Survey Telescope for Astronomy. Credit: Background: ESO, M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit. Streamlines: NASA/SOFIA

Studying the system revealed the orbit was almost circular. Given that one of the stars had collapsed into a black hole, the nearly circular orbit and the lack of any evidence of an explosion all point to a star that collapsed completely. The complete collapse meant that all matter from the star collapsed into the blackhole and no material escaped out as a supernova. Could it be then that the team have finally revealed the mechanism by which massive stars have been vanishing? It certainly looks like it but further observations of binary systems with stars and black holes is required to confirm. 

Source : Constraints on Neutrino Natal Kicks from Black-Hole Binary VFTS 243

The post Hundreds of Massive Stars Have Simply Disappeared appeared first on Universe Today.

Human visitors to Mars need somewhere to shelter from the radiation, temperature swings, and dust storms that plague the planet. If the planet is anything like Earth or the Moon, it may have large underground lava tubes that could house shelters. Collapsed sections of lava tubes, called skylights, could provide access to these subterranean refuges.

Does this hole on Mars lead to a larger underground cavern?

This image was captured by the High-Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO). The pit is only a few meters across and is in the Arsia Mons region of Mars. Arsia Mons is one of the three dormant volcanos in the Tharsis Montes group of three volcanos.

This colourized image of the surface of Mars was created with data from the Mars Reconnaissance Orbiter. The line of three volcanoes is Tharsis Montes, with Olympus Mons to the northwest and Valles Marineris to the east. Arsia Mons is the southernmost volcano of the three that comprise Tharsis Montes. Image: NASA/JPL-Caltech/ Arizona State University

The Tharsis Region of Tharsis Bulge is a vast volcanic plain that’s thousands of kilometres across. It’s elevated compared to the rest of Mars and averages about 10km (33,000 ft) above the planet’s mean elevation. The region was volcanically active in the past, obviously, and features like the pit are a direct result of ancient volcanic activity.

Several pits in the Arsia Mons region may be collapsed skylights or openings into subterranean lava tubes. However, there is much uncertainty. An image of one of them shows an illuminated sidewall, which could indicate that it’s just a cylindrical pit.

These images of a pit near Arsia Mons were captured several years ago. The image on the left was captured first, and scientists wondered if it could lead to a lava tube or cave. Then, the image on the right, showing a side wall, was captured. The side wall could indicate that there’s no tube or cave. Image Credit: NASA/JPL/University of Arizona

The hole in the featured image could be only a pit or shaft and not an entrance to a cave or lava tube. They’re found on Hawaiian volcanos, where they’re called pit craters. They don’t connect to long caves or lava tubes. They’re the result of a collapse that happened much deeper underground.

These four sequential images show how pit craters form. As volcanos erupt and settle, cracks form. They slowly migrate upwards, and rocks above them start to fall into them. Eventually, the upward migrating crack reaches the surface, and the roof caves in. On Earth, plants will eventually colonize the crater. On Mars, they stay much the same as when they collapsed. Image Credit: US National Park Service.

In Hawaii, the pit craters range from 6 to 186 m (20 to 610 feet) deep and from 8 to 1140 m (26 to 3,740 feet) wide. The Arsia Mons pit in the leading image is only about 178 m (584 feet) deep.

We have a much better understanding of lava pits and tubes on the Moon than we do on Mars. We know some of them are thermally stable at about 17 C (63 F.) We also have better images of them, with intriguing glimpses of boulder-covered floors.

Spectacular high Sun view of the Mare Tranquillitatis pit crater revealing boulders on an otherwise smooth floor. The 100-meter pit may provide access to a lunar lava tube. Image Credit: By NASA/GSFC/Arizona State University – http://photojournal.jpl.nasa.gov/catalog/PIA13518, Public Domain, https://commons.wikimedia.org/w/index.php?curid=54853313

Lots of thinking is going into how to explore these lunar caves and lava tubes, including conceptual designs for robots that could explore them. Maybe on the Moon, astronauts could take shelter in inflatable habitats inside these tubes, where they’re protected from temperature swings, radiation, and micrometeorites.

But Mars is another question. There’s no reason that lava tubes shouldn’t exist on Mars. In fact, Mars’ gravity is much weaker than Earth’s, and that should allow for much larger tubes. Images of Mars show rilles, which are collapsed tubes. It seems likely that not all of these tubes have collapsed to form rilles.

One pit on the Martian volcano, Pavis Mons, is particularly intriguing. There’s some kind of void under the pit, but the nature of the pit is difficult to ascertain. Is it a lava tube? If it is, it dwarfs most tubes on Earth.

Martian lava tubes are still a mystery. Scientists have found plenty of morphological evidence suggesting that they’re plentiful. But in science, you can’t assume they’re there, even though it seems likely that they are. There’s no clear reason why they wouldn’t be. Could they one day provide shelter for astronauts? Maybe.

We need a robotic mission to explore them first.

The post What’s Under This Hole on the Surface of Mars? appeared first on Universe Today.

When trying to measure molecular structures with nanometer precision, every bit of noise shows up in the data: someone walking past the microscope, tiny vibrations in the building and even the traffic outside. A new processing technique removes noise from optical microscope data in real time, allowing scientists to track individual molecules over 10 times more precisely than was possible before.

In 2018, astronomers detected an exoplanet around the star 40 Eridani. It’s about 16 light-years away in the constellation Eridanus. The discovery generated a wave of interest for a couple of reasons. Not only is it the closest Super-Earth around a star similar to our Sun, but the star system is the fictional home of Star Trek’s Vulcan science officer, Mr. Spock.

It’s always fun when a real science discovery lines up with science fiction.

Eridani’s other name is HD 26965, and it’s actually a triple-star system. Astronomers discovered the system’s lone planet, Eridani b, using the radial velocity method. Orbiting planets tug on their stars, and the star’s movement creates a change in its spectrum. Astronomical telescopes with spectrometers can detect the changes.

Jian Ge, an astronomy professor at the University of Florida, led the study that presented the discovery in 2018. At the time, Ge said in a press release, “The new planet is a ‘super-Earth’ orbiting the star HD 26965, which is only 16 light years from Earth, making it the closest super-Earth orbiting another Sun-like star. The planet is roughly twice the size of Earth and orbits its star with a 42-day period just inside the star’s optimal habitable zone.”

A super-Earth in the habitable zone around a Sun-similar star ‘only’ 16 light-years away is an intriguing discovery. Its link with a beloved Star Trek character gave the discovery wings, and word spread.

However, in the intervening years, follow-up observations have not confirmed Eridani b’s existence. A 2021 study suggested that the change in the star’s spectrum was a false positive. Now, a new study says that the exoplanet fondly named Vulcan does not exist.

The study is “The Death of Vulcan: NEID Reveals That the Planet Candidate Orbiting HD 26965 Is Stellar Activity.” It’s published in The Astronomical Journal, and the lead author is Abigail Burrows, an astronomer at Dartmouth College.

“We revisit the long-studied radial velocity (RV) target HD 26965 using recent observations from the NASA-NSF “NEID” precision Doppler facility,” Burrows and her co-authors write. After a deeper, line-by-line analysis of the radial velocity data, “… we demonstrate that the claimed 45-day signal previously identified as a planet candidate is most likely an activity-induced signal.”

Activity-induced signal means that the signal comes from the star’s activity, not from the external tug of an exoplanet.

Vulcan’s initial detection was based on data from the Dharma Planet Survey (DPS.) DPS monitored about 150 nearby Sun-like stars for changes in their spectra. Data from the Keck Telescope and the HARPS planet-finding spectrograph also contributed to the discovery.

When the planet was detected in 2018, the discoverers recommended caution. They presented the data as they collected it, along with their best interpretation. That’s standard in science, and they were careful in calling it a candidate planet. In their paper, they also discussed “the possibility that the RV signal is actually produced by stellar rotation modulated activity.” That activity could be sunspots, convection irregularities, or other things.

But in the end, they concluded that what they were seeing was likely a planet.

“By carefully examining the RV data in the active and quiet phases of the star, and after carefully considering all possible stellar activity sources, we concluded that the coherent signal seen from HD 26965 is most likely from a planet, with some RV noise contributed by stellar activity,” the authors wrote in the 2018 paper.

The rest of us were happy to agree because finding a super-Earth around a nearby Sun-like star is the kind of thing we hope to find.

“Men sometimes see exactly what they wish to see.”

-Spock of Vulcan

Sadly for Vulcan, the newest research shows that the stellar activity isn’t noise. It accounts for the entire signal.

The new results are based on NEID, the NN-explore Exoplanet Investigations with Doppler spectroscopy. It’s a high-resolution spectrometer attached to the WIYN (Wisconsin-Indiana-Yale-NOIRLab) telescope at Kitt Peak Observatory. The researchers used NEID to capture 63 spectra from Eridani over a six-month period.

NEID revealed a lot of information about the star, including things like contrast and radial velocity. Together, NEID data paints a more complete picture of the star and its activity. In this new work, Burrows and her co-researchers showed that all of this activity lines up with the star’s 42-day rotation period.

“All measurements show a strong signal at or near the 42-day stellar rotation period,” they write.

This figure from the study shows NEID data on the left. “All data show clear rotational modulation at or near the 42-day period,” the authors write. The right shows periodograms for the data, which show “clear power at the stellar rotation period of ?42 days.” Image Credit: Burrows et al. 2024

The authors write that their work “points toward a decaying starspot or plage” as the source of the signal. A plage is a bright spot on a star’s chromosphere. They used a variety of methods to reach this conclusion. “While each of these methods taken individually may not rule out a potential planetary signal at the same phase and period as the activity signal, collectively, our analyses show that an activity hypothesis is favoured over the specific planet claimed in Ma et al. (2018),” they conclude.

“When you eliminate the impossible, whatever remains, however improbable, must be the truth.”

Spock of Vulcan

The authors of the new paper didn’t set out to debunk Vulcan. Their paper is part of an effort to better understand the periodic and quasi-periodic spectral changes from Sun-like stars. Without a better understanding, annoying false positives will cloud our understanding of exoplanets, especially Earth-like ones around Sun-like stars. “To reach the precision necessary to detect temperate, Earth-mass extrasolar planets (exoplanets) around Sun-like stars using the radial velocity (RV) technique, the community must improve Doppler measurement precision significantly from the current state of the art,” they write.

“Detecting and characterizing these exo-Earths is vital for future spaceborne direct imaging missions, which will set the scientific priorities for the coming decade,” the authors explain.

The post Sorry Spock, But “Vulcan” Isn’t a Planet After All appeared first on Universe Today.

Image privacy could be protected with the use of generative artificial intelligence. Researchers created a system which replaces parts of images that might threaten confidentiality with visually similar but AI-generated alternatives. Named 'generative content replacement,' in tests, 60% of viewers couldn't tell which images had been altered. The researchers intend for this system to provide a more visually cohesive option for image censoring, which helps to preserve the narrative of the image while protecting privacy.

Researchers recently published findings that could lay the groundwork for applying quantum computing methods to protein structure prediction.

Researchers demonstrated a quantum algorithmic speedup with the quantum approximate optimization algorithm, laying the groundwork for advancements in telecommunications, financial modeling, materials science and more.

Researchers demonstrated a quantum algorithmic speedup with the quantum approximate optimization algorithm, laying the groundwork for advancements in telecommunications, financial modeling, materials science and more.

Sometimes, it seems like habitable worlds can pop up almost anywhere in the universe. A recent paper from a team of citizen scientists led by researchers at the Flatiron Institute might have found an excellent candidate to look for one – on a moon orbiting a mini-Neptune orbiting a star that is also orbited by another star.

That’s a lot of things orbiting each other, so let’s dive into some details of the star system known as TOI 4633. It has two potential planets. One has a relatively short 34-day orbit but whose existence was only found by radial velocity measurements, as it doesn’t cross between the Earth and its host star. It also has yet to be confirmed by exoplanet hunters.

Another planet, known for now at TOI 4633c, is much more intriguing. It falls into the size category of a “mini-Neptune,” meaning it is slightly smaller than the 8th planet in our solar system but is likely still a gas giant with a thick atmosphere. It orbits its host star once every 272 days – making it one of the 40 longest-orbiting planets out of the thousands discovered so far.

Binaries are just one of a class of multiple-star systems, as Fraser explains.

That long orbit also puts it in the habitable zone of its host star – about .85 AU away from the G-type star it is orbiting. Being in the habitable zone would imply that liquid water could exist on its surface. However, the size of the planet and the likely density of its atmosphere would rule out the possibility of surface water on the planet itself.

However, there is a relatively good chance that TOI 4633c could have a moon. Planets with longer orbits tend to accrue them (hence why Venus and Mercury don’t have any in our own solar system). Such a small world wouldn’t have the same restrictive constraints as its gas-giant host planet, meaning it could potentially be habitable, such as the moons Pandora in the Avatar franchise or Endor in Star Wars.

But what makes this system even more unique is that the star TOI 4633c is orbiting is itself being orbited by another star. It wasn’t long ago that we weren’t even sure if planets could exist in these “binary” systems, and how strange life might be on one has become prominent recently with the popularity of The Three-Body Problem. But in theory, binary systems have habitable zones, and planets can survive in a stable orbit around at least one of the stars.

TESS’ primary mission is compete, but its data is still a treasure trove of new discoveries, as Fraser covers.

The smaller star orbits around its larger binary companion only once every 230 years and gets close enough to the other star to be considered relatively close by interstellar standards. As of now, it’s unclear what, if any, effect this proximity to another star would have on TOI 4633c, but it’s doubtful that it would be a world like Tatooine. 

However, the system lacks similarities to famous fictional examples, and it makes up for its potential to solve some long-standing problems in planetary formation theory. In addition to searching for a potential exomoon around TOI 4633c, scientists will continue to monitor the system closely to see if it remains stable. They can also see how the current known (and theorized) planets fit into existing models of planetary system formation.

This is another feather in the cap of the Planet Hunters TESS citizen science collaboration. There are undoubtedly more strange star systems out there for them to find. If you’re interested in helping them, you can sign up here.

Learn More:
NASA – Discovery Alert: Mini-Neptune in Double Star System is a Planetary Puzzle
Eisner et al. – Planet Hunters TESS. V. A Planetary System Around a Binary Star, Including a Mini-Neptune in the Habitable Zone
UT – Marvel at the Variety of Planets Found by TESS Already
UT – A New Venus-Sized World Found in the Habitable Zone of its Star

Lead Image:
Artist’s depiction of the binary system TOI 4633 and its potentially habitable planet.
Credit – Ed Bell for Simons Foundation

The post A Mini-Neptune in the Habitable Zone in a Binary Star System appeared first on Universe Today.

A survey of 253 US teens has found that, on average, their mood lifted after using their smartphones

Babies seem to cluster together their squeals and growling noises, rather than making them sporadically, which suggests they are part of their preparation for talking

Researchers demonstrated a scalable, modular hardware platform that integrates thousands of interconnected qubits onto a customized integrated circuit. This 'quantum-system-on-chip' (QSoC) architecture enables them to precisely tune and control a dense array of qubits.

New research has determined the spatial structure of various processes of a novel gene-editing tool called 'prime editor.' Functional analysis based on these structures also revealed how a 'prime editor' could achieve reverse transcription, synthesizing DNA from RNA, without 'cutting' both strands of the double helix. Clarifying these molecular mechanisms contributes greatly to designing gene-editing tools accurate enough for gene therapy treatments.

Engineers establish the link between oxygen and graphene quality and present an oxygen-free chemical vapor deposition method (OF-CVD) that can reproducibly create high-quality samples for large-scale production. The graphene they synthesized with their new method proved nearly identical to exfoliated samples and was capable of producing the fractional quantum Hall effect.

Artificial intelligence (AI) combined with a novel bio-inspired camera achieves 100 times faster detection of pedestrians and obstacles than current automotive cameras. This important step for computer vision and AI and can greatly improve the safety of automotive systems and self-driving cars.

Artificial intelligence (AI) combined with a novel bio-inspired camera achieves 100 times faster detection of pedestrians and obstacles than current automotive cameras. This important step for computer vision and AI and can greatly improve the safety of automotive systems and self-driving cars.

The moon orbiting the asteroid Dinkinesh is actually two tiny moons stuck together. Collectively called 'Selam,' the two moonlets bring new insight into the complex processes behind planetary formation and evolution.

Researchers have applied the well-understood and highly verified quantum field theory, usually applied to the study of the very small, to a new target, the early universe. Their exploration led to the conclusion that there ought to be far fewer miniature black holes than most models suggest, though observations to confirm this should soon be possible. The specific kind of black hole in question could be a contender for dark matter.

Researchers have developed an assistive machine learning model that greatly improves the ability of medical professionals to read the electroencephalography (EEG) charts of intensive care patients. Because EEG readings are the only method for knowing when unconscious patients are in danger of suffering a seizure or are having seizure-like events, the computational tool could help save thousands of lives each year.