Showing posts sorted by relevance for query homunculus. Sort by date Show all posts
Showing posts sorted by relevance for query homunculus. Sort by date Show all posts

Monday, August 28, 2006

Homunuclus

Church teaching holds that in-vitro fertilization is morally wrong because it replaces the conjugal union between husband and wife and often results in the destruction of embryos. Artificial insemination for married couples is allowable if it "facilitates" the sex act but does not replace it. The church condemns all forms of experimentation on human embryos.Vatican Critical of Stem Cell Creation

The current pope was once Cardinal Ratzinger the Vatican's chief Inquisitor, yes I know we weren't expecting the Spanish Inquistion.

When the issue of cloning and artificial life was presented for JP2, Ratzinger issued the churches statement on bio-ethics which has not changed since the Rennisance when the Church banned sorcery and the creation of artificial life known as the Homunculus And indeed Ratzinger in his paper, refers to cloning as creating a homonucleus. 21st Century science meets the middle ages.

Does the law permit the ìenhancementî or other manipulation of one's genetic outfit? In this context, the following issues were discussed at the seminar: reproduction techniques in general (the "homunculus issue," see Goethe's Faust 11), special issues of "reprogenetics," cloning (inherently wrong, or open to an evaluation between healing effects and human dignity by way of a rule-and- exception relationship?), disease prevention (MV, cancers), unfairly advantaging certain children in view of a "level playing field" of genetic outfits, right of parents to genetically manipulate their offspring, and liability of parents who do not manipulate.The New Genetics and the Law

The crowning example of alchemical hybris came with the claim of pseudo-Paracelsus in the sixteenth century that he could make a homunculus - an artificial man. Like the gold of the alchemists, which was said to exceed the 24 carats of the best natural gold, the homunculus was supposed to be better than a natural man. Being made in a flask from human semen,
he was free of the catamenial substance that, according to the current theories of generation, supplied the material basis to an ordinary fetus. According to pseudo-Paracelsus, the homunculus was a semi-spiritual being that had an immediate apprehension of all the arts and a preternatural intelligence. In modern terms, the homunculus could be called the perfect test-tube baby, engineered to have the highest possible intelligence quota and aptitude. I have written an article focusing on this topic ("The Homunculus and his Forebears," 1999; see Vita), and have a book focusing on alchemy and the art-nature debate under contract (
Promethean Ambitions: Alchemy and the Refashioning of Nature, forthcoming with University of Chicago Press). Newton's Alchemy, recreated

What can we make of his account of the creation of a homunculus, a
miniature human being, in his laboratory? Cloning and genetic engineering are clearly impossible with 16th-century technology.
Paracelsus

The invention of hand lenses and the microscope facilitated studies of the chick embryo by Marcello Malpighi (1628-1694), but also gave rise to one of the most profound errors in describing human development, that of the homunculus. This was a miniature human believed to have been seen within the head of a human spermatozoon and which presumed to enlarge when deposited in the female. This was the basis of the preformation theory and was believed by many well into the 18th century.lifeissues.net | When Does Human Life Begin? The Final Answer

Drawing of Human Spermatozoa
1694
The drawing was conceived by Niklaas Hartsoeker not by what
he had seen, but what he presumed would be visible if sperm
could be adequately viewed.




Consider the profound difficulty embryonic development presents to an observer. A complex organism, such as a chick, frog, insect or human, arises in an orderly and magical way from an apparently structureless egg. When embryology was in its infancy in the 17th and 18th centuries, the thought was that no animal could arise from such nothingness. Thus was born the theory of the homunculus: the idea that an infinite set of tiny individuals were contained, one within another, in each egg—or in each sperm (there was vigorous disagreement as to which). Development was seen as the visible unfolding of a preexisting individual. Unhappily for this wonderful notion, in the late 18th century Caspar Friedrich Wolff showed by microscopy that embryos contained cells but no homunculus—there was no preformed entity.
American Scientist Online - In the Twinkle of a Fly

U.S. Senator Sam Brownback (R-Kansas) recently told his fellow Republicans he would advance a two-year moratorium rather than a permanent ban. Ironically, Brownback relayed his intentions while President Bush reaffirmed his opposition to human embryo cloning in a speech delivered by satellite to the Southern Baptist Convention in St. Louis. Bush told them, "We believe that a life is a creation, not a commodity, and that our children are gifts to be loved and protected, not products to be designed and manufactured by human cloning." How did we get so quickly from a few cells in a dish to children? It reminds me of artists' representations during the Middle Ages of the homunculus: an invisibly tiny, fully formed human carried around by the male and then deposited in the female during intercourse. The tiny homunculus would eventually grow into a fetus before it was born. Those were the days before the discoveries of the microscope, sperm and egg. So then maybe Bush and Bevilacqua imagine that people still reproduce with homunculi. Otherwise, describing what we know with absolute certainty are nothing more than single or several cells in a microscopic cluster, resembling the cells inside your cheek, as "children" simply doesn't make any sense! If these men didn't wield so much power, we'd laugh at their ignorance. Stem Cells and Cloning: What Bush Doesn't Know Might Kill You ...

Faust and Homunculus
19th century engraving of Goethe's Faust and Homunculus




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Friday, September 29, 2023

Watch a 180-year-old star eruption unfold in new time-lapse movie (video)

Samantha Mathewson
Wed, September 27, 2023 


Watch a 180-year-old star eruption unfold in new time-lapse movie (video)

Using over two decades of data from NASA’s Chandra X-ray Observatory, astronomers have crafted a stunning new video of a stellar eruption that took place some 180 years ago.

The time-lapse video uses Chandra observations from 1999, 2003, 2009, 2014 and 2020 — along with data from ESA’s XMM-Newton spacecraft — and retraces the history of the stellar explosion known as Eta Carinae. This famous star system contains two massive stars. One of those stars is about 90 times more massive than the sun, scientists say, while the other is  about 30 times more massive than the sun.

The massive explosion, dubbed the "Great Eruption, came from Eta Carinae. It is believed to be the result of a merger between two stars that originally belonged to a triple star system. The aftermath of the collision was witnessed on Earth in the mid-19th century, and the new video shows how the stellar eruption has since continued to rapidly expand into space at speeds reaching up to 4.5 million miles per hour , according to a statement from NASA.

Related: Eta Carinae's epic supernova explosion comes to life in new visualization

"During this event, Eta Carinae ejected between 10 and 45 times the mass of the sun,” NASA officials said in the statement. "This material became a dense pair of spherical clouds of gas, now called the Homunculus Nebula, on opposite sides of the two stars."

The Homunculus Nebula is the bright blue cloud at the center of the image, fueled by high-energy X-rays produced by the two massive stars, which are too close to be observed individually. They are surrounded by a bright orange ring of X-ray emissions that appear to grow and expand rapidly over time.

"The new movie of Chandra, plus a deep, summed image generated by adding the data together, reveal important hints about Eta Carinae’s volatile history," NASA officials said in the statement. "This includes the rapid expansion of the ring, and a previously-unknown faint shell of X-rays outside it.

The faint X-ray shell is outlined in the image above, showing that it has a similar shape and orientation to the Homunculus nebula, which suggests both structures have a common origin, according to the statement.

Based on the motion of clumps of gas, astronomers believe  the stellar material was blasted away from Eta Carinae sometime between the years 1200 and 1800 — well before the Great Eruption was observed in 1843. As the blast extended into space, it collided with interstellar material in its path. The collision then heated the material, creating the bright X-ray ring observed. However, the blast wave has now traveled beyond the ring, given the X-ray brightness of Eta Carinae has faded with time, scientists said.

Their findings on Eta Carinae’s expansion were published in a 2022 study in the Astrophysical Journal.

"We’ve interpreted this faint X-ray shell as the blast wave from the Great Eruption in the 1840s," Michael Corcoran at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who led the study, said in a statement from the Chandra X-ray Observatory. "It tells an important part of Eta Carinae’s backstory that we wouldn’t otherwise have known."

Wednesday, July 03, 2024

HOMUNCULUS
Work on synthetic human embryos to get code of practice in UK


Ian Sample Science editor
Wed, 3 July 2024

Stem cell-based embryo models made global headlines last summer when researchers said they had created one with a heartbeat and traces of blood.Photograph: Ahmad Gharabli/AFP/Getty Images


Biological models of human embryos that can develop heartbeats, spinal cords and other distinctive features will be governed by a code of practice in Britain to ensure that researchers work on them responsibly.

Made from stem cells, they mimic, to a greater or less extent, the biological processes at work in real embryos. By growing them in the laboratory, scientists hope to learn more about how human embryos develop and respond to their environment, questions that would be impossible to answer with real embryos donated for research.

Scientists have worked on stem cell-based embryo models, or SCBEMs, for many years, but the technology only made global headlines last summer when researchers said they had created one with a heartbeat and traces of blood. Made without the need for eggs or sperm, the ball of cells had some features that would typically appear in the third or fourth week of pregnancy.


The technology, which advocates believe could shed fresh light on potential causes of infertility, is so new that SCBEMs are not directly covered by UK law or regulations. The situation leaves the scientists pursuing the research in an uncomfortable grey area. The new guidelines, drawn up by experts at the University of Cambridge and the Progress Educational Trust, aim to clarify the situation by setting down rules and best practice.

Dr Peter Rugg-Gunn, a member of the code of practice working group, said the guidance took “stem cell-based embryo models out of the grey zone and on to more stable footing”. It should also reassure the public that research is being performed carefully and under proper scrutiny, added Rugg-Gunn, who is a group leader at the Babraham Institute.

The code reminds researchers that there may be “a range of emotional responses” to SCBEMs with heartbeats, spinal cords and other recognisable features, and urges them to be “aware of and sensitive to these concerns, irrespective of whether they are thought to be ethically or legally relevant”.

Under existing UK law, scientists can grow real human embryos donated for research for up to 14 days in the lab, though many argue for the limit to be extended to allow for the study of later stages of embryonic development.

The new guidelines establish an oversight committee that will decide on a case-by-case basis how long specific embryo models can be grown for. The code does not rule out experiments that grow them for more than 14 days, but Roger Sturmey, professor of reproductive medicine at Hull York medical school and chair of the code of practice working group said any such experiments “would have to be very well justified”.

The code prohibits any human SCBEMs from being transferred into the womb of a human or animal, or being allowed to develop into a viable organism in the lab.

Sandy Starr, the deputy director of the Progress Educational Trust, said he expected researchers, funders, research institutes, publishers and regulators to recognise the guidelines. Scientists who worked outside the code would “find it difficult to publish, find funding and face opprobrium from their peers”,” he added.


Monday, December 29, 2025

'No immigration for a decade': Bannon pushes Trump to ban all immigrants for 10 years

David Edwards
December 29, 2025 
RAW STORY


Real America's Voice/screen grab

MAGA influencer Steve Bannon is calling on President Donald Trump to ban all immigration into the United States for at least 10 years

During a Monday interview with MyPillow CEO Mike Lindell on Real America's Voice, Bannon used alleged fraud in the daycare industry to push for Somali immigrants to be deported.

"They're stealing money and laughing in your face," Bannon said. "When somebody shows up, they got a million-in-one excuse, and they play dumb: 'Oh, I don't know, you're white, I don't speak the language.' They've got to all be deported."

"If you can't figure out there's $9 billion missing, you're in the wrong business," Lindell, a candidate for Minnesota governor, agreed. "And then transparency, Steve, I'll tell you what, I'll be the most transparent governor this country's ever seen. The people are going to know where the problems lie, and then we fix them."

Bannon then told anti-immigration activist Rosemary Jenks that Trump should implement "a 10-year moratorium on immigration."

"No immigration!" he insisted. "Not just getting rid of the H-1B visas, but moratoriums across the board on no immigration for a decade until we get this mess sorted out."

"I think most Americans would say, yeah, okay, what's wrong with that?" Jenks replied. "Nothing at all."

"We're done. It's over. We're not doing this anymore. We are not paying taxes so that you can throw our money away. We need a moratorium," she added. "It would go probably longer, for 10 years actually."

"You got to get rid of H-1Bs today and ship them all home and give those jobs for American citizens," Bannon agreed. "And then a 10-year moratorium on every other program."


"That's how long it's going to take to take this thing back to the basics and reconstruct it."



'Twisted homunculus' Stephen Miller nailed for his 'dumb as a box of hair' hate screeds


Tom Boggioni
December 29, 2025 
RAW STORY


A series of anti-immigrant posts by Donald Trump adviser Stephen Miller over the holiday weekend got a swift dismissal by longtime conservative Charlie Sykes, who questioned the intelligence of the president’s resident “evil genius.”

On his Substack platform, Sykes noted the controversial Miller making broad-based attacks on immigrants, including writing what Sykes sarcastically characterized as a “Deep Thought.”

Miller wrote he watched a Christmas special with his family that featured Frank Sinatra and Dean Martin and commented, “Imagine watching that and thinking America needed infinity migrants from the third world.”

Critics have fired back at Miller and pointed out, “Enjoy your racism grift while it lasts. Dean Martin’s dad came here from Italy at a time when Italy was considered third-world. Both of Frank Sinatra’s parents came here from Italy.”

Sykes pointed out that Miller wasn’t done sneering.

“Someone should write an alternate historical novel where Americans are the first to master the automobile, the first in flight, the first to harness the atom, the first to land on the moon — but just keep going and never open our borders to the entire third world for sixty years,” Miller claimed — ignoring the substantial number of foreign scientists who made major contributions to the Manhattan Project.

That led Sykes to launch a broadside at Trump’s key adviser.

“My contrarian take: I hope Stephen Miller goes on tweeting, because it exposes not merely his rancid bigotry (which was known), but also his invincible ignorance, because it turns out that this twisted homunculus — the evil genius behind Trump’s mass deportations — is actually as dumb as a box of hair,” he wrote.

You can read here.

















Wednesday, December 18, 2024

SPACE / COSMOS

NASA again delays return of astronauts stranded on space station


Agence France-Presse
December 18, 2024 

U.S. astronauts Suni Williams (L) and Butch Wilmore took off aboard Boeing's Starliner in June 2024 for what was meant to be an eight-day mission -- they now will not return until spring 2025 (Handout)

Two U.S. astronauts stranded for months on the International Space Station will remain there at least until late March, NASA said Tuesday as it announced another delay in the mission to bring them home.

Veteran astronauts Butch Wilmore and Suni Williams arrived at the ISS in June aboard Boeing's Starliner spacecraft, and were due to spend eight days on the orbiting laboratory.

But problems arose with the Starliner's propulsion system during the flight there, so NASA opted for a big change in plans.

After weeks of intensive tests on the Starliner, the space agency decided to return it to Earth without its crew, and to bring the two stranded astronauts back home with the members of a SpaceX mission called Crew-9.

Crew-9's two astronauts arrived at the ISS aboard a Dragon spacecraft in late September, with two empty seats for Wilmore and Williams. The plan was for all four to return home in February 2025.

But NASA said Tuesday that Crew-10, which would relieve Crew-9 and the stranded pair, would now launch no earlier than March 2025, and both teams would remain on board for a "handover period."

"The change gives NASA and SpaceX teams time to complete processing on a new Dragon spacecraft for the mission," NASA said in a blog post.

The bottom line is that Wilmore and Williams will spend more than nine months in space, rather than eight days as initially planned.

SpaceX, the private company founded by billionaire Elon Musk, has been flying regular missions every six months to allow the rotation of ISS crews.


How to catch a supernova explosion before it happens – and what we can learn from it


The Conversation
December 18, 2024 

Composite image of Homunculus Nebula. 
ESA/Hubble/WikipediaCC BY-SA

Stars are born, live and die in spectacular ways, with their deaths marked by one of the biggest known explosions in the Universe. Like a campfire needs wood to keep burning, a star relies on nuclear fusion — primarily using hydrogen as fuel — to generate energy and counteract the crushing force of its own gravity.

But when the fuel runs out, the outward pressure vanishes, and the star collapses under its own weight, falling at nearly the speed of light, crashing into the core and rebounding outward. Within seconds, the star is violently blown apart, hurling stellar debris into space at speeds thousands of times faster than the most powerful rocket ever built. This is a supernova explosion.

Astronomers aim to understand what types of stars produce different kinds of explosions. Do more massive stars result in brighter explosions? What happens if a star is surrounded by dust and gas when it explodes?

While we have simulations modeling a star’s death, they are difficult to validate. Observing a star’s behavior in real-time before the explosion could help answer these questions — but finding such a star is no easy task.

Scientists already do this with eruptions on Earth. Volcanologists monitor volcanoes, measuring changes in activity to predict an upcoming eruption. For example, in March 1980, Mount St. Helens in the US began to show some precursor events, such as seismic activity, and dozens of steam eruptions ejecting ash and gas into the atmosphere.


Plumes of steam, gas, and ash often occurred at Mount St. Helens in the early 1980s. Wikipedia

Two months later, an earthquake triggered the largest landslide ever recorded, releasing built up pressure in the magma chamber, resulting in a catastrophic eruption that devastated an area of almost 232 square miles (600 square kilometers).

Pre-supernova eruptions

Massive stars – larger than around 10 times the mass of the Sun – can do the same thing, albeit at much larger scales. In 2009, astronomers observed a bright event 65 million light years away that on first impressions resembled a supernova explosion.

Dubbed SN 2009ip, the explosion did not brighten as expected and was reclassified shortly after discovery as a “supernova impostor” – a giant eruption which ultimately does not destroy the star.

Over the next three years, the star underwent many rapid “flickering” events, a bit like quickly turning on and off a light bulb. Finally, in 2012, an unexpected supernova occurred. The evolution of the supernova explosion is still being studied to this day, and what exactly happened from 2009 to 2012 remains a mystery.

In a recent paper, published in Astronomy and Astrophysics, our team found a peculiar star in the Virgo Cluster, coincidentally also 65 million light years away. Unlike SN 2009ip, the star lacked hydrogen and was composed primarily of helium. The star was observed very slowly increasing its brightness for over five years – akin to slowly turning on a bulb using a dimmer switch – before a supernova was observed.

The supernova, labelled as SN 2023fyq, provided astronomers with a rare opportunity to capture the first light from the supernova explosion, known as shock breakout, from observatories worldwide and in space, largely due to the daily monitoring of the precursor activity.

Clash with current theory

This precursor activity offers an exciting chance to uncover the mysteries of supernova explosions, shedding light on both the conditions leading up to and following these cosmic events.

The underlying cause of this pre-supernova activity remains unclear. It is thought that an isolated massive star does not experience such rapid fluctuations in brightness. In the final moments of a star’s life, its core undergoes rapid evolution, desperately attempting to counteract the crushing force of gravity with its dwindling fuel reserves.

However, the star is so large at this stage that any activity in the core doesn’t have enough time to reach the surface. Observing these dramatic changes, occurring so close to the star’s demise, present a significant challenge to current theories.


One compelling hypothesis points to the interaction of multiple stars. Stars are born in dense clouds of gas and dust where multiple stars can form in close proximity. Neighboring stars may interact gravitationally with one another – exchanging material as they orbit each other.

This mass transfer could account for the changes in brightness observed in SN 2009ip before its explosion and the hydrogen deficiency seen in SN 2023fyq. The companion involved might be another massive star – or perhaps a more exotic object, such as a black hole.

We know not all eruptions will not end in a supernova explosion. For example, in the 1840s, Eta Carinae – a star 100 times larger than the Sun – experienced the “Great Eruption” launching 30 times the Sun’s mass into space. Although this was an extremely energetic explosion, the massive star was not destroyed.


Do all stars announce their departure? We aren’t sure. Seemingly normal supernovas have been observed with precursor eruptions, thanks in part to deep observations catching the faint precursor activity.

In 2025, the Vera C. Rubin Observatory, equipped with the world’s largest camera, will begin to study these events. At 3,200-megapixels, it is over 40 times more sensitive than cameras we have available on Earth, providing the opportunity to search for fainter precursor activity.

At Stockholm University, our team is currently using telescopes from the European Southern Observatory and the Zwicky Transient Facility, including the Nordic Optical Telescope in La Palma, Spain and the Very Large Telescope at Cerro Paranal in the Atacama Desert of northern Chile, to identify the signs that indicate a star is nearing the end of its life.

By recognising these signals, we can alert the scientific community and be ready to watch as a star experiences its final, dramatic moments.

Seán Brennan, Postdoctoral Reseracher in the Supernova and Explosive Transient Group, Stockholm University

This article is republished from The Conversation under a Creative Commons license. Read the original article.


Human settlement of Mars isn’t as far off as you might think

The Conversation
December 18, 2024 

The planet Mars (AFP)

Could humans expand out beyond their homeworld and establish settlements on the planet Mars? The idea of settling the red planet has been around for decades. However, it has been seen by sceptics as a delusion at best and mere bluster at worst.

Mars might seem superficially similar to Earth in a number of ways. But its atmosphere is thin and humans would need to live within pressurised habitats on the surface.

Yet in an era where space tourism has become possible, the red planet has emerged as a dreamland for rich eccentrics and techno utopians. As is often the case with science communication, there’s a gulf between how close we are to this ultimate goal and where the general public understands it to be.

However, I believe there is a rationale for settling Mars and that this objective is not as far off as some would believe. There are actually a few good reasons to be optimistic about humanity’s future on the red planet.

First, Mars is reachable. During an optimal alignment between Earth and Mars as the two planets orbit the Sun, its possible to travel there in a spacecraft in six to eight months. Some very interesting new engine designs suggest that it could be done in two months. But based on technology that’s ready to go, it would take astronauts six months to travel to Mars and six months back to Earth.

Astronauts have already stayed for this long on the International Space Station (ISS) and on the Soviet orbiting lab Mir. We can get there safely and we have already shown that we can reliably land robots on the surface. There’s no technical reason why we couldn’t do the same with humans.

Second, Mars is abundant in the raw materials required for humans to “live off the land”, in other words, achieve a level of self sufficiency. The red planet has plentiful carbon, nitrogen, hydrogen and oxygen which can be separated and isolated, using processes developed on Earth. Mars is interesting and useful in a multitude of ways that the moon isn’t. And we have technology on Earth to enable us to stay and settle Mars by making use of its materials.

A third reason for Mars optimism is the radical new technology that we can put to use on a crewed mission to the planet. For example, Moxie (Mars Oxygen In-Situ Resource Utilization Experiment) is an project developed by scientists at the California Institute of Technology (Caltech) that sucks in Martian atmosphere and separates it into oxygen. Byproducts of the process – carbon monoxide, nitrogen and argon – can be vented.

When scaled up, similar machines would be able to separate oxygen from hydrogen to produce breathable air, rocket fuel and water. This makes it easier to travel to the planet and live on the surface because it’s not necessary to bring these commodities from Earth – they can be made once on Mars. Generating fuel on the surface would also make any future habitat less reliant on electric or solar-powered vehicles.

But how would we build the habitats for our Mars settlers? Space architect Melodie Yasher has developed ingenious plans for using robots to 3D print the habitats, landing pads and everything needed for human life on Mars. Using robots means that these could all be manufactured on Mars before humans landed. 3D printed homes have already been demonstrated on Earth.

Volunteers have also spent time living in simulated Mars habitats here on Earth. These are known as Mars analogues. The emergency medicine doctor Beth Healey spent a year overwintering in Antarctica (which offers many parallels with living on another planet) for the European Space Agency (Esa) and communicates her experience regularly.

She is not alone, as each year sees new projects in caves, deserts and other extreme environments, where long term studies can explore the physical and psychological demands on humans living in such isolated environments.

Finally, the Mars Direct plan devised by Dr Robert Zubrin has existed for more than 30 years, and has been modified to account for modern technology as the private sector has grown. The original plan was based on using a Saturn V rocket (used for the Apollo missions in the 1960s and 1970s) to launch people. However, this can now be accomplished using the SpaceX Falcon 9 rocket and a SpaceX Dragon capsule to carry crew members.


Elon Musk wants to use his Starship vehicle to establish large settlements on Mars. SpaceXCC BY-NC

Several uncrewed launches from Earth could ferry necessary equipment to Mars. These could include a vehicle for crew members to return on. This means that everything could be ready for the first crew once they arrived.

For astronauts making the journey to Mars, radiation is the biggest problem. But using certain materials in the walls of the spacecraft or building a protective shelter inside the vehicle could shield astronauts from high energy particles. Similar ideas could apply to 3D printed habitats on the Martian surface. Alternatively, settlers could live underground or in Martian caves.

On Mars, there’s a 24-minute communication delay with Earth. This means that Martians will need to be self-sustaining and less reliant on their homeworld from the beginning. While this could pose challenges, they are not insurmountable.

Elon Musk’s Starship vehicle, which launches on the most powerful rocket ever built, could be a game changer. Starship is currently undergoing testing at SpaceX’s facility in southern Texas. It is hard to overstate what a reliable Starship, that has been cleared to carry humans, could do for exploration of the moon and Mars.

Lower costs, higher payloads and larger crews all make for a far more efficient programme of lunar and Martian exploration. Yet even without it, everything we need to travel to Mars is currently available or in exciting late stages of development. There will not be a shortage of well-suited astronauts eager to go.

Sam McKee, Associate Tutor and PhD Candidate in Philosophy of Science, Manchester Metropolitan University


This article is republished from The Conversation under a Creative Commons license. Read the original article.


First ever binary star found near our galaxy’s supermassive black hole




ESO

Location of binary star D9 in the Milky Way 

image: 

This image indicates the location of the newly discovered binary star D9, which is orbiting Sagittarius A*, the supermassive black hole at the centre of our galaxy. It is the first star pair ever found near a supermassive black hole. The cut-out shows  the binary system as detected by the SINFONI spectrograph on ESO’s Very Large Telescope. While the two stars cannot be discerned separately in this image, the binary nature of D9 was revealed by the spectra captured by SINFONI over several years. These spectra showed that the light emitted by hydrogen gas around D9 oscillates periodically towards red and blue wavelengths as the two stars orbit each other.

view more 

Credit: ESO/F. Peißker et al., S. Guisard




An international team of researchers has detected a binary star orbiting close to Sagittarius A*, the supermassive black hole at the centre of our galaxy. It is the first time a stellar pair has been found in the vicinity of a supermassive black hole. The discovery, based on data collected by the European Southern Observatory’s Very Large Telescope (ESO’s VLT), helps us understand how stars survive in environments with extreme gravity, and could pave the way for the detection of planets close to Sagittarius A*.

Black holes are not as destructive as we thought,” says Florian Peißker, a researcher at the University of Cologne, Germany, and lead author of the study published today in Nature Communications. Binary stars, pairs of stars orbiting each other, are very common in the Universe, but they had never before been found near a supermassive black hole, where the intense gravity can make stellar systems unstable.

This new discovery shows that some binaries can briefly thrive, even under destructive conditions. D9, as the newly discovered binary star is called, was detected just in time: it is estimated to be only 2.7 million years old, and the strong gravitational force of the nearby black hole will probably cause it to merge into a single star within just one million years, a very narrow timespan for such a young system.

This provides only a brief window on cosmic timescales to observe such a binary system — and we succeeded!” explains co-author Emma Bordier, a researcher also at the University of Cologne and a former student at ESO.

For many years, scientists also thought that the extreme environment near a supermassive black hole prevented new stars from forming there. Several young stars found in close proximity to Sagittarius A* have disproved this assumption. The discovery of the young binary star now shows that even stellar pairs have the potential to form in these harsh conditions. “The D9 system shows clear signs of the presence of gas and dust around the stars, which suggests that it could be a very young stellar system that must have formed in the vicinity of the supermassive black hole,” explains co-author Michal Zajaček, a researcher at Masaryk University, Czechia, and the University of Cologne.

The newly discovered binary was found in a dense cluster of stars and other objects orbiting Sagittarius A*, called the S cluster. Most enigmatic in this cluster are the G objects, which behave like stars but look like clouds of gas and dust. 

It was during their observations of these mysterious objects that the team found a surprising pattern in D9. The data obtained with the VLT’s ERIS instrument, combined with archival data from the SINFONI instrument, revealed recurring variations in the velocity of the star, indicating D9 was actually two stars orbiting each other. “I thought that my analysis was wrong,” Peißker says, “but the spectroscopic pattern covered about 15 years, and it was clear this detection is indeed the first binary observed in the S cluster.”

The results shed new light on what the mysterious G objects could be. The team proposes that they might actually be a combination of binary stars that have not yet merged and the leftover material from already merged stars.

The precise nature of many of the objects orbiting Sagittarius A*, as well as how they could have formed so close to the supermassive black hole, remain a mystery. But soon, the GRAVITY+ upgrade to the VLT Interferometer and the METIS instrument on ESO’s Extremely Large Telescope (ELT), under construction in Chile, could change this. Both facilities will allow the team to carry out even more detailed observations of the Galactic centre, revealing the nature of known objects and undoubtedly uncovering more binary stars and young systems. “Our discovery lets us speculate about the presence of planets, since these are often formed around young stars. It seems plausible that the detection of planets in the Galactic centre is just a matter of time,” concludes Peißker.

More information

This research was presented in the paper “A binary system in the S cluster close to the supermassive black hole Sagittarius A*” published today in Nature Communications (doi: 10.1038/s41467-024-54748-3).

The team is composed of F. Peißker (Institute of Physics I, University of Cologne, Germany [University of Cologne]), M. Zajaček (Department of Theoretical Physics and Astrophysics, Masaryk University, Brno, Czechia; University of Cologne), L. Labadie (University of Cologne), E. Bordier (University of Cologne), A. Eckart (University of Cologne; Max Planck Institute for Radio Astronomy, Bonn, Germany), M. Melamed (University of Cologne), and V. Karas (Astronomical Institute, Czech Academy of Sciences, Prague, Czechia).

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration for astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, Czechia, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as survey telescopes such as VISTA. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates ALMA on Chajnantor, a facility that observes the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society. 

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Young exoplanet’s atmosphere unexpectedly differs from its birthplace



New study shows planet formation might be more complicated than previously thought



Northwestern University

PDS 70 

image: 

The natal disk of PDS 70 with new planet PDS 70b (bright spot on the right). By studying this system, researchers uncovered a mismatched composition of gases in the planet’s atmosphere compared to gases within the disk.

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Credit: ESO/A. Müller et al.




Just as some children physically resemble their parents, many scientists have long thought that developing planets should resemble the swirling disk of gas and dust that births them.

But, in a new study, a Northwestern University-led team of astrophysicists discovered the resemblance might be looser than previously thought. By studying a still-forming exoplanet and its surrounding natal disk, the researchers uncovered a mismatched composition of gases in the planet’s atmosphere compared to gases within the disk.

The surprising finding potentially confirms long-held skepticism that scientists’ current model of planet formation is too simplified.

The study will be published on Wednesday (Dec. 18) in the Astrophysical Journal Letters. It marks the first time physicists have compared information from an exoplanet, its natal disk and host star.

“For observational astrophysicists, one widely accepted picture of planet formation was likely too simplified,” said Northwestern’s Chih-Chun “Dino” Hsu, who led the study. “According to that simplified picture, the ratio of carbon and oxygen gases in a planet’s atmosphere should match the ratio of carbon and oxygen gases in its natal disk — assuming the planet accretes materials through gases in its disk. Instead, we found a planet with a carbon and oxygen ratio that is much lower compared to its disk. Now, we can confirm suspicions that the picture of planet formation was too simplified.”

Hsu is a postdoctoral associate at the Center for Interdisciplinary Exploration and Research in Astrophysics(CIERA). He is advised by Jason Wang, an assistant professor of physics and astronomy at Northwestern’s Weinberg College of Arts and Sciences and member of CIERA.

Searching for visible birth material

All planets are born from a natal disk, a rotating disk of gas and dust that surrounds a new star. Over millions of years, gravity pulls gas and dust together to form clumps, which eventually grow into planets. Until recently, it was impossible to obtain a direct view of a natal disk in order to track a planet’s birth. Most observable exoplanets are too old, so their natal disks have already disappeared.

The exception, however, is PDS 70, a natal disk that envelopes two fledgling gas-giant exoplanets — similar to Jupiter — called PDS 70b and PDS 70c. Located just 366 million lightyears from Earth within the constellation Centaurus, the planets are, at most, a youthful 5 million years old.

“This is a system where we see both planets still forming as well as the materials from which they formed,” Wang said. “Previous studies have analyzed this disk of gas to understand its composition. For the first time, we were able to measure the composition of the still-forming planet itself and see how similar the materials are in the planet compared to the materials in the disk.”

Examining planetary fingerprints

To measure the materials, Hsu, Wang and their team examined the light emitted from PDS 70b. This light, or spectra, is like a fingerprint, revealing an object’s composition, motion, temperature and other characteristics. Each molecule or element produces its own spectrum. So, by studying these spectra, researchers can pinpoint the specific molecules or elements within an object.

In previous work, Wang co-developed new photonics technologies that enable astronomers to capture the spectrum of targeted faint objects near much brighter stars. The researchers used this technique to zero in on the faint features of the young planetary system.

“These new tools make it possible to take a really detailed spectra of faint objects next to really bright objects,” Wang said. “Because the challenge here is there’s a really faint planet next to a really bright star. It’s hard to isolate the light of the planet in order to analyze its atmosphere.”

With the spectra, the researchers obtained information about carbon monoxide and water from PDS 70b. From that, they calculated the inferred ratio of carbon and oxygen within the planet’s atmosphere. Then, they compared that ratio to previously reported measurements of gases in the disk.

“We initially expected the carbon-to-oxygen ratio in the planet might be similar to the disk,” Hsu said. “But, instead, we found the carbon, relative to oxygen, in the planet was much lower than the ratio in the disk. That was a bit surprising, and it shows that our widely accepted picture of planet formation was too simplified.”

Solid components might make the difference

To explain this mismatch, Hsu and Wang think two different scenarios might be at play. One explanation is the planet might have formed before its disk became enriched in carbon. Another explanation is the planet might have grown mostly by absorbing large amounts of solid materials in addition to gases. While the spectra show only gases, some of the carbon and oxygen initially could be accreted from solid — trapped in ice and dust.

“If the planet preferentially absorbed ice and dust, then that ice and dust would have evaporated before going into the planet,” Wang said. “So, it might be telling us that we can’t just compare gas versus gas. The solid components might be making a big difference in the carbon to oxygen ratio.”

For this study, the team only studied PDS 70b. Next, they plan to observe the spectra from the other planet in the PDS 70 system.

“By studying these two planets together, we can understand the system’s formation history even better,” Hsu said. “But, also, this is just one system. Ideally, we need to identify more of them to better understand how planets form.”

The study, “PDS 70b shows stellar-like carbon-to-oxygen ratio,” was supported by the Heising-Simons Foundation, the Simons Foundation and the National Science Foundation.