The disk in question, called a circumplanetary disk, surrounds the exoplanet PDS 70c, one of two giant, Jupiter-like planets orbiting a star nearly 400 light-years away. Astronomers had found hints of a "moon-forming" disk around this exoplanet before but, since they could not clearly tell the disk apart from its surrounding environment, they could not confirm its detection—until now.
In addition, with the help of ALMA, Benisty and her team found that the disk has about the same diameter as the distance from our Sun to the Earth and enough mass to form up to three satellites the size of the Moon.
But the results are not only key to finding out how moons arise. "These new observations are also extremely important to prove theories of planet formation that could not be tested until now," says Jaehan Bae, a researcher from the Earth and Planets Laboratory of the Carnegie Institution for Science, U.S., and author on the study.
Planets form in dusty disks around young stars, carving out cavities as they gobble up material from this circumstellar disk to grow. In this process, a planet can acquire its own circumplanetary disk, which contributes to the growth of the planet by regulating the amount of material falling onto it. At the same time, the gas and dust in the circumplanetary disk can come together into progressively larger bodies through multiple collisions, ultimately leading to the birth of moons.
But astronomers do not yet fully understand the details of these processes. "In short, it is still unclear when, where, and how planets and moons form," explains ESO Research Fellow Stefano Facchini, also involved in the research.
"More than 4000 exoplanets have been found until now, but all of them were detected in mature systems. PDS 70b and PDS 70c, which form a system reminiscent of the Jupiter-Saturn pair, are the only two exoplanets detected so far that are still in the process of being formed," explains Miriam Keppler, researcher at the Max Planck Institute for Astronomy in Germany and one of the co-authors of the study.
"This system therefore offers us a unique opportunity to observe and study the processes of planet and satellite formation," Facchini adds.
PDS 70b and PDS 70c, the two planets making up the system, were first discovered using ESO's Very Large Telescope (VLT) in 2018 and 2019 respectively, and their unique nature means they have been observed with other telescopes and instruments many times since.
The latest high resolution ALMA observations have now allowed astronomers to gain further insights into the system. In addition to confirming the detection of the circumplanetary disk around PDS 70c and studying its size and mass, they found that PDS 70b does not show clear evidence of such a disk, indicating that it was starved of dust material from its birth environment by PDS 70c.
An even deeper understanding of the planetary system will be achieved with ESO's Extremely Large Telescope (ELT), currently under construction on Cerro Armazones in the Chilean Atacama desert. "The ELT will be key for this research since, with its much higher resolution, we will be able to map the system in great detail," says co-author Richard Teague, a researcher at the Center for Astrophysics | Harvard & Smithsonian, U.S.. In particular, by using the ELT's Mid-infrared ELT Imager and Spectrograph (METIS), the team will be able to look at the gas motions surrounding PDS 70c to get a full 3D picture of the system.
More from Astronomy and Astrophysics
Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form. For general feedback, use the public comments section below (please adhere to guidelines).
Please select the most appropriate category to facilitate processing of your request
Thank you for taking time to provide your feedback to the editors.
Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.
Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.
Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we'll never share your details to third parties.
Medical research advances and health news
The latest engineering, electronics and technology advances
The most comprehensive sci-tech news coverage on the web
Read full article at Phys.org
22 July, 2021 - 04:11pm
Updated 8:01 AM ET, Thu July 22, 2021
22 July, 2021 - 04:11pm
We may be watching the birth of a moon for the first time. Astronomers have spotted a disc of debris around a distant planet called PDS 70 c, and it is massive enough that the young exoplanet might be in the process of forming exomoons.
When a new stellar system is forming, the planets coalesce out of a cloud of debris called a circumstellar disc. Then, the planets can suck gas and dust from that cloud to form their own circumplanetary discs, which feed the planets’ growth and provide the material for moons to form.
The star PDS 70, which is about 370 light-years from Earth, has provided researchers with a unique laboratory to study this process. Its two giant planets, PDS 70 b and c, are the only two that have been observed while still embedded in their circumstellar disc. Now Myriam Benisty at the Université Grenoble Alpes in France and her colleagues have confirmed that PDS 70 c – and maybe PDS 70 b as well – also has a circumplanetary disc.
“We know lots of planets, but those are done planets, and we have to use models to try to understand how planets form by looking at the final product,” says Alessandro Morbidelli at Côte d’Azur Observatory in France, who wasn’t involved in this work. “With these two, we are directly seeing how giant planets and their moons form, so these planets are exceptional.”
The researchers spotted this disc using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. There had been hints of a circumplanetary disc there before, but never anything conclusive.
They found that, depending on the size of the dust grains in the disc around PDS 70 c, it probably contains a total dust mass that is about 0.7 to 3.1 per cent the mass of Earth. “We cannot identify any moons that are being formed, but there is enough material to form them, and it is very likely that satellites are forming there,” says Benisty. The planet is a few times more massive than Jupiter, so it may eventually form many moons just like Jupiter has, she says.
“Looking outward from the planet, it would be similar to how the Milky Way looks on a really dark night, this shining stripe across the night sky, but it would be much, much broader,” says team member Richard Teague at the Harvard-Smithsonian Center for Astrophysics in Massachusetts. PDS 70 b probably also has a disc, but it isn’t as bright, which could mean that it is made of smaller dust grains or just gas, says Benisty.
The researchers also found streams of dust flowing from the outer circumstellar disc towards the star, into the area where, if this stellar system is like our own, smaller rocky planets could form. “The streamers are bringing material from the outer disc to the inner disc, and that is not only important for the formation of Earth-like planets, but also the star is still a baby star so it’s still accreting matter to grow,” says Benisty.
This system provides us with a window to study the formation of planets and moons generally, but with its two giant planets mirroring Jupiter and Saturn it is also reminiscent of our own solar system, albeit larger. It could help us understand how the planets and moons in our solar system formed and evolved.
Journal reference: The Astrophysical Journal Letters, in print
22 July, 2021 - 04:11pm
The star and planets in this Atacama Large Millimeter/submillimeter Array radio image cannot be seen—these wavelengths reveal only dust. The bright dot at the center of the enlarged image is the hottest, innermost part of the dust disk around PDS 70c.
In the past 3 decades, astronomers have spotted more than 4000 planets orbiting other stars in our Milky Way Galaxy. It seems inevitable that some of them—or the billions of other planets in the Milky Way—must have moons. After all, more than 200 moons zing around the measly eight planets in our own Solar System. Observers have yet to find such exomoons, but they may have just spotted the next best thing: a disk of dust around a young exoplanet that they believe contains a moon, or moons, in the making.
The find is “really promising,” says University of Western Ontario astronomer Chris Fox, who was not involved in the new observation. “It’s hard to imagine that moons would not form.”
The youthful star system, known as PDS 70, is a mere 10 million years old and it contains two protoplanets, or planets that are still being formed, says Myriam Benisty of the University of Grenoble. In 2018, Benisty’s team used the European Southern Observatory’s (ESO’s) Very Large Telescope (VLT) in Chile to discover the first of those planets, dubbed PDS 70b, orbiting in a gap in the disk of dust and gas around the star. Such gaps provide indirect evidence for planets, which are thought to collect material and sweep a clean path as they orbit. The gaps, Benisty says, “are screaming, ‘Please come and find the planets!’” A year later, another team using the VLT found a second planet—PDS 70c—slightly farther out than the first. Both are gas giants several times more massive than Jupiter.
Wanting to know more, the team focused all possible instruments on the system, Benisty says. In 2020, they found a hint of dust around PDS 70c using the Atacama Large Millimeter/submillimeter Array (ALMA), a collection of 66 short-wavelength radio dishes in Chile. But it was hard to distinguish the planet’s dust from the nearby bright disk of dust orbiting the star. ALMA’s dishes can be moved, and the next time they were arranged across their widest possible extent—which gives the finest angular resolution—the team observed PDS 70 again. The result, published today in Astrophysical Journal Letters, is a clear image of a circumplanetary dust disk around PDS 70c. “It seems to still have dust available to form satellites,” Benisty says. “They may have formed already, but we can’t see them with ALMA.”
PDS 70c’s partner, PDS 70b, seems not to have accumulated as much dust. That may be because the material is coming from the large disk orbiting the star farther out and drifting inward, Benisty says. If so, PDS 70c is likely intercepting the infalling dust, depriving its partner of a share.
The system is providing plenty of ground truth for theorists pondering planet formation, who have so far been largely starved of data. “This is the only way to test if they are right or wrong,” Benisty says. So far, PDS 70c has done little to trouble them. Its disk spans a distance slightly wider than that between Earth and the Sun, and it has a mass roughly three times that of our Moon—figures that are both in line with expectation. “The circumplanetary disk is consistent with theory,” Fox says, but on the presence of moons, “it’s not conclusive proof yet.”
That may have to wait for newer, sharper eyed instruments. ESO’s 39-meter Extremely Large Telescope, now under construction in Chile, might just be able to take a snapshot of any protomoons swirling in the dust. “It would be awesome if we could pinpoint the spot,” Fox says.
Daniel is Science’s senior correspondent in the United Kingdom, covering astronomy, physics, and energy stories as well as European policy.
22 July, 2021 - 01:02pm
For the first time, scientists have clearly identified a ring of gas and dust circling a planet outside our solar system -- a discovery that could help reveal how planets and moons are formed, a study showed Thursday.
The disc surrounds an exoplanet dubbed PDS 70c, one of two gas giants similar in size and mass to Jupiter that orbit the star PDS 70, nearly 400 light years from our solar system.
Astronomers from the European Southern Observatory discovered PDS 70c in 2019 using their Very Large Telescope.
Those observations combined with high-resolution images from the ALMA telescope, also in Chile, allowed them to conclude that PDS 70c's disk holds material that will allow moons to form around the planet, said the study, published in The Astrophysical Journal Letters.
Astronomers have known since 2006 that the star PDS 70 is surrounded by a very large ring of material but limitations on the observational equipment only allowed them to guess at the presence of a planet between the star and the ring.
"Our ALMA observations were obtained at such exquisite resolution that we could clearly identify that the disc is associated with the planet, and we are able to constrain its size for the first time," the study's lead author Myriam Benisty said in a press release.
Both planets discovered in the system hold major interest for researchers because they belong to a young star system.
The star PDS 70 is 5.4 million years old -- a spring chicken compared to our Sun, which has been around for 4.6 billion years.
Miriam Keppler, a researcher at the Max Planck institute and study co-author, discovered PDS 70b in 2018.
"More than 4,000 exoplanets" -- planets outside our solar system -- "have been found until now, but all of them were detected in mature systems," she said in the press release.
"PDS 70b and PDS 70c, which form a system reminiscent of the Jupiter-Saturn pair, are the only two exoplanets detected so far that are still in the process of being formed."
The material surrounding PDS 70c is enough to form our moon three times over. Jupiter, which is a much older planet, has four moons and dozens of smaller satellites.
22 July, 2021 - 10:00am
July 22 (Reuters) - Scientists for the first time have spotted a moon-forming region around a planet beyond our solar system - a Jupiter-like world surrounded by a disk of gas and dust massive enough that it could spawn three moons the size of the one orbiting Earth.
The researchers used the ALMA observatory in Chile's Atacama desert to detect the disk of swirling material accumulating around one of two newborn planets seen orbiting a young star called PDS 70, located a relatively close 370 light years from Earth. A light year is the distance light travels in a year, about 5.9 trillion miles (9.5 trillion km).
It is called a circumplanetary disk, and it is from these that moons are born. The discovery, the researchers said, offers a deeper understanding about the formation of planets and moons.
More than 4,400 planets have been discovered outside our solar system, called exoplanets. No circumplanetary disks had been found until now because all the known exoplanets resided in "mature" - fully developed - solar systems, except the two infant gas planets orbiting PDS 70.
"These observations are unique - so far - and have been long waited for, in order to test the theory of planet formation and directly observe the birth of planets and of their satellites," said astronomer Myriam Benisty of the University of Grenoble, who led the study published on Thursday in the Astrophysical Journal Letters.
In our solar system, the impressive rings of Saturn, a planet around which more than 80 moons orbit, represent a relic of a primordial moon-forming disk, said study co-author Stefano Facchini of the European Southern Observatory.
The orange-colored star PDS 70, roughly the same mass as our sun, is about 5 million years old - a blink of the eye in cosmic time. The two planets are even younger.
Both planets are similar (although larger) to Jupiter, a gas giant that is our solar system's biggest planet. It was around one of the two planets, called PDS 70c, that a moon-forming disk was observed. Researchers previously had found initial evidence of a disk around this planet, but now have confirmed it.
Both planets are "still in their youth," Facchini said, and are at a dynamic stage in which they are still acquiring their atmospheres. PDS 70c orbits its star at 33 times the distance of the Earth from the sun, similar to the planet Neptune in our solar system. Benisty said there are possible additional so-far undetected planets in the system.
Stars burst to life within clouds of interstellar gas and dust scattered throughout galaxies. Leftover material spinning around a new star then coalesces into planets, and circumplanetary disks surrounding some planets similarly yield moons.
The dominant mechanism thought to underpin planet formation is called "core accretion," said study co-author Richard Teague of the Harvard-Smithsonian Center for Astrophysics.
"In this scenario, small dust grains, coated in ice, gradually grow to larger and larger sizes through successive collisions with other grains. This continues until the grains have grown to a size of a planetary core, at which point the young planet has a strong enough gravitational potential to accrete gas which will form its atmosphere," Teague said.
Some nascent planets attract a disk of material around them, with the same process that gives rise to planets around a star leading to the formation of moons around planets.
The disk around PDS 70c, with a diameter about equal to the distance of the Earth to the sun, possesses enough mass to produce up to three moons the size of Earth's moon. It is unclear how many will form, if any.
Our Standards: The Thomson Reuters Trust Principles.
Scientists for the first time have spotted a moon-forming region around a planet beyond our solar system - a Jupiter-like world surrounded by a disk of gas and dust massive enough that it could spawn three moons the size of the one orbiting Earth.
The most comprehensive solution to manage all your complex and ever-expanding tax and compliance needs.
The industry leader for online information for tax, accounting and finance professionals.
Information, analytics and exclusive news on financial markets - delivered in an intuitive desktop and mobile interface.
Access to real-time, reference, and non-real time data in the cloud to power your enterprise.
Screen for heightened risk individual and entities globally to help uncover hidden risks in business relationships and human networks.
All quotes delayed a minimum of 15 minutes. See here for a complete list of exchanges and delays.
© 2021 Reuters. All rights reserved
22 July, 2021 - 07:05am
The discovery was made by scientists using the European Southern Observatory’s (ESO) Atacama Large Millimeter/submillimeter Array (ALMA) to image the star system PDS 70, which sits roughly 400 light-years away from Earth in the constellation Centaurus.
PDS 70 consists of a parent star around which two enormous protoplanets are known to orbit. It is thought that these worlds, which were imaginatively named PDS 70b and PDS 70c, share key characteristics with the gas giants Jupiter and Saturn that orbit in our home solar system.
As the newly formed planets orbited in the dust-choked environment surrounding the young star, their gravitational influence allowed them to collect the material and add it to their mass. This in turn created an enormous, relatively debris-free cavity surrounding the parent star which is easily identifiable in the wide field view of PDS 70.
Earlier observations of the outermost exoplanet PDS 70c had hinted at the presence of a circumplanetary disk surrounding the growing world. However, it was not until the higher resolution imaging capabilities of ALMA were brought to bear that astronomers were able to reveal the impressive nature of the structure.
“Our work presents a clear detection of a disc in which satellites could be forming,” comments Myriam Benisty, lead author of the study and a researcher at the University of Grenoble, France, and at the University of Chile. “Our ALMA observations were obtained at such exquisite resolution that we could clearly identify that the disc is associated with the planet and we are able to constrain its size for the first time.”
The team behind the study believes that the vast circumplanetary disk seen in the ALMA data is comprised from material that was collected by PDS 70c as it swept the inner solar system soon after its creation. According to the study authors, it is around 500 times larger than Saturn’s rings, and spans a region of space that is roughly the equivalent to the gulf that separates Earth from the Sun. Some of the material in the disk will continue to accrete into the planet, prolonging its growth. However the remainder could also give rise to the formation of new moons.
This formation process echoes the one by which planets form around a star. Tiny collisions in the disk structure give rise to clumps of matter that continue to grow and siphon material from the surrounding environment until they become a fully fledged moon. The authors of the study estimate that the ring surrounding PDS 70c harbors enough material to create three satellites the size of Earth’s Moon.
The new ALMA imagery will allow astronomers to test existing theories on how planets and moons come to form. The system will also present a tantalizing target for the next generation of observatories, including the European 40-meter Extremely Large Telescope, which is currently being constructed in Chile.
The paper has been published online in The Astrophysical Journal Letters.
The video below shows an animation of PDS 70 in motion.
22 July, 2021 - 07:00am
Using the Atacama Large Millimetre/submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, astronomers have unambiguously detected the presence of a disc around a planet outside our Solar System for the first time. The observations will shed new light on how moons and planets form in young stellar systems.
“Our work presents a clear detection of a disc in which satellites could be forming,” says Myriam Benisty, a researcher at the University of Grenoble, France, and at the University of Chile, who led the new research published today in The Astrophysical Journal Letters. “Our ALMA observations were obtained at such exquisite resolution that we could clearly identify that the disc is associated with the planet and we are able to constrain its size for the first time,” she adds.
The disc in question, called a circumplanetary disc, surrounds the exoplanet PDS 70c, one of two giant, Jupiter-like planets orbiting a star nearly 400 light-years away. Astronomers had found hints of a “moon-forming” disc around this exoplanet before but, since they could not clearly tell the disc apart from its surrounding environment, they could not confirm its detection — until now.
This image, taken with the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, shows the PDS 70 system, located nearly 400 light-years away and still in the process of being formed. The system features a star at its center and at least two planets orbiting it, PDS 70b (not visible in the image) and PDS 70c, surrounded by a circumplanetary disc (the dot to the right of the star). The planets have carved a cavity in the circumstellar disc (the ring-like structure that dominates the image) as they gobbled up material from the disc itself, growing in size. It was during this process that PDS 70c acquired its own circumplanetary disc, which contributes to the growth of the planet and where moons can form. Credit: ALMA (ESO/NAOJ/NRAO)/Benisty et al.
In addition, with the help of ALMA, Benisty and her team found that the disc has about the same diameter as the distance from our Sun to the Earth and enough mass to form up to three satellites the size of the Moon.
But the results are not only key to finding out how moons arise. “These new observations are also extremely important to prove theories of planet formation that could not be tested until now,” says Jaehan Bae, a researcher from the Earth and Planets Laboratory of the Carnegie Institution for Science, USA, and author on the study.
This image, taken with the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, shows a close-up view on the moon-forming disc surrounding PDS 70c, a young Jupiter-like gas giant nearly 400 light-years away. It shows this planet and its disc center-front, with the larger circumstellar ring-like disc taking up most of the right-hand side of the image. The dusty circumplanetary disc is as large as the Sun-Earth distance and has enough mass to form up to three satellites the size of the Moon. Credit: ALMA (ESO/NAOJ/NRAO)/Benisty et al.
Planets form in dusty discs around young stars, carving out cavities as they gobble up material from this circumstellar disc to grow. In this process, a planet can acquire its own circumplanetary disc, which contributes to the growth of the planet by regulating the amount of material falling onto it. At the same time, the gas and dust in the circumplanetary disc can come together into progressively larger bodies through multiple collisions, ultimately leading to the birth of moons.
But astronomers do not yet fully understand the details of these processes. “In short, it is still unclear when, where, and how planets and moons form,” explains ESO Research Fellow Stefano Facchini, also involved in the research.
“This system therefore offers us a unique opportunity to observe and study the processes of planet and satellite formation,” Facchini adds.
This colorful image shows the sky around the faint orange dwarf star PDS 70 (in the middle of the image). The bright blue star to the right is χ Centauri. Credit: ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin
The latest high-resolution ALMA observations have now allowed astronomers to gain further insights into the system. In addition to confirming the detection of the circumplanetary disc around PDS 70c and studying its size and mass, they found that PDS 70b does not show clear evidence of such a disc, indicating that it was starved of dust material from its birth environment by PDS 70c.
This chart shows the southern constellation of Centaurus and marks most of the stars visible to the unaided eye on a clear dark night. The dwarf star PDS 70 is marked with a red circle. Credit: ESO, IAU and Sky & Telescope
An even deeper understanding of the planetary system will be achieved with ESO’s Extremely Large Telescope (ELT), currently under construction on Cerro Armazones in the Chilean Atacama desert. “The ELT will be key for this research since, with its much higher resolution, we will be able to map the system in great detail,” says co-author Richard Teague, a researcher at the Center for Astrophysics | Harvard & Smithsonian, USA. In particular, by using the ELT’s Mid-infrared ELT Imager and Spectrograph (METIS), the team will be able to look at the gas motions surrounding PDS 70c to get a full 3D picture of the system.
The team is composed of Myriam Benisty (Unidad Mixta Internacional Franco-Chilena de Astronomía, CNRS, Departamento de Astronomía, Universidad de Chile, Santiago de Chile, Chile and Université Grenoble Alpes, CNRS, Grenoble, France [UGA]), Jaehan Bae (Earth and Planets Laboratory, Carnegie Institution for Science, Washington DC, USA), Stefano Facchini (European Southern Observatory, Garching bei München, Germany), Miriam Keppler (Max Planck Institute for Astronomy, Heidelberg, Germany [MPIA]), Richard Teague (Center for Astrophysics | Harvard & Smithsonian, Cambridge, MA, USA [CfA]), Andrea Isella (Department of Physics and Astronomy, Rice University, Houston, TX, USA), Nicolas T. Kurtovic (MPIA), Laura M. Perez (Departamento de Astronomía, Universidad de Chile, Santiago de Chile, Chile [UCHILE]), Anibal Sierra (UCHILE), Sean M. Andrews (CfA), John Carpenter (Joint ALMA Observatory, Santiago de Chile, Chile), Ian Czekala (Department of Astronomy and Astrophysics, Pennsylvania State University, PA, USA, Center for Exoplanets and Habitable Worlds, Davey Laboratory, Pennsylvania State University, PA, USA, Center for Astrostatistics, Davey Laboratory, Pennsylvania State University, PA, USA and Institute for Computational & Data Sciences, Pennsylvania State University, PA, USA), Carsten Dominik (Anton Pannekoek Institute for Astronomy, University of Amsterdam, The Netherlands), Thomas Henning (MPIA), Francois Menard (UGA), Paola Pinilla (MPIA and Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, UK) and Alice Zurlo (Núcleo de Astronomía, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Santiago de Chile, Chile and Escuela de Ingeniería Industrial, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Santiago de Chile, Chile).
ESO is the foremost intergovernmental astronomy organization in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, 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 carries out an ambitious program focused on the design, construction, and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organizing cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal, and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-meter Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky.”
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.
Great; now they will witness firsthand the power of plasma-electromagnetism, and the verification of predictions of many previously ignored scientists. The accretion by gravity model will be finally debunked. I mean, Haumea already did debunk it, but no one was paying attention.
Did anyone notice that the star in the center of the dust halo is dimmer than the planet that orbits it? Now, how can that be? In the video, the none existent star has been edited to be as bright as a solar body. Why the editing?
Email address is optional. If provided, your email will not be published or shared.
SciTechDaily: Home of the best science and technology news since 1998. Keep up with the latest scitech news via email or social media.
An international team anchored by the Event Horizon Telescope (EHT) Collaboration, which is known for capturing the first image of a black hole in the…
Copyright © 1998 - 2021 SciTechDaily. All Rights Reserved.
22 July, 2021 - 07:00am
The birth of moons surrounding a distant Jupiter-like exoplanet has been observed for the first time, giving astronomers insight into early planetary systems.
They were created from a dusty circle surrounding a gas giant world that is 370 light years from the Earth, explained astronomers from University of Grenoble, France.
The planet, named PDS 70c, is in orbit around the very young 5.4 million-year-old star PDS 70, which is three quarters the mass of the Sun, and is still in the process of forming new planets - including the very new PDS 70c and sister world PDS 70b.
There is enough debris circling PDS 70c to produce three moons about the same size as the one that orbits the Earth, the astronomers explained.
While every star system is thought to contain at least one planet, it is assumed many planets will have at least one, but likely multiple moons. Jupiter has 79 and counting.
The discovery opens a window into the evolution of the universe, as moons around gas giants are thought to hold more potential for finding life than planets.
This image, taken with the ALMA telescope shows wide (left) and close-up (right) views of the moon-forming disc surrounding PDS 70c
The planet, named PDS 70c (artist impression), is in orbit around the very young 5.4 million-year-old star PDS 70, which is three quarters the mass of the Sun, and is still in the process of forming new planets - including the very new PDS 70c and sister world PDS 70b.
The host star is very young, just 5.4 million years old, and so still has a protoplanetary disc of its own - pictured in the outer edge of this artist impression. The star is on the left and the planet PDS 70c is seen centre
Moons, also known as natural satellites, have been discovered in many shapes, sizes and types.
They are usually sold bodies, and some even have an atmosphere and are similar in size to a small planet.
Most planetary moons probably formed from the discs of gas and dust circulating around planets in early star systems, according to NASA.
There are hundreds of moons in our solar system and some asteroids have been found to have a moon.
Of the terrestrial planets of the inner solar system, neither Mercury nor Venus have any moons at all, Earth has one and Mars has its two small moons.
To date no exomoons have been discovered in other planetary systems, although a number of potential candidates exist.
It isn't clear yet whether exomoons are rare, or whether we haven't developed the technology to detect them yet.
The name for a moon orbiting another moon would be a moonmoon, although no examples have been found of this phenomenon.
Images from the ALMA observatory in Chile show that the moon-forming disc has a diameter of around 100 million miles - about the distance of the Sun to the Earth.
There is enough debris whizzing round to make up to three moons the size of the Earth's, according to the team behind the discovery.
The planet is one of a pair found two years ago in the constellation of Centaurus, orbiting the very young 5.4 million-year-old star PDS 70.
The giant planet, PDS 70c, is twice as large as Jupiter and takes 227 years to complete a single orbit of its host star, acquiring its own 'circumplanetary disc' where moons can take shape, during its formation.
Dr Benisty said: 'Our ALMA observations were obtained at such exquisite resolution we could clearly identify the disk is associated with the planet. We are able to constrain its size for the first time.'
It has a similar structure to the one which gave rise to the 79 moons of Jupiter.
Dr Sean Andrews, co-author of this study, from the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, said they used the millimetre emission from cool dust grains to estimate how much mass is in the disk.
This allowed them to then determine that it was a potential reservoir for forming a satellite system around PDS 70c, and learn more about the formation of moons.
Gas and dust clouds merge into progressively larger bodies through multiple collisions - ultimately leading to their birth.
But the exact processes have never been caught in the act - until now.
Dr Stefano Facchini, of the European Southern Observatory (ESO), also involved in the study, said it is still unclear when, where, and how planets and moons form.
Within the large protoplanetary disc encircling PDS 70 are two young planets, one on the right is twice the size of Jupiter and has a circumplanetary disc, the other, similar to Saturn, doesn't
Circumplanetary discs disappear within around 10million years after the formation of the planet, and emerged in our solar system less than four billion years ago.
Co author Dr Miriam Keppler, of the Max Planck Institute for Astronomy, Heidelberg, Germany, said 4,000 exoplanets have so far been discovered, but all are in mature systems, where the discs have already disappeared.
'PDS 70b and PDS 70c, which form a system reminiscent of the Jupiter-Saturn pair, are the only two exoplanets detected so far that are still being formed.'
This shows a close-up view on the moon-forming disc surrounding PDS 70c, a young Jupiter-like gas giant nearly 400 light-years away. It shows this planet and its disc centre-front, with the larger circumstellar ring-like disc taking up most of the right-hand side of the image
The system features a star at its centre and at least two planets orbiting it, PDS 70b (not visible in the image) and PDS 70c, surrounded by a circumplanetary disc (the dot to the right of the star). The planets have carved a cavity in the circumstellar disc (the ring-like structure that dominates the image) as they gobbled up material from the disc itself, growing in size
The two planets were first spotted using ESO's Very Large Telescope (VLT) in 2018 and 2019 respectively, and have been watched many times since.
Added Dr Facchini: 'This system therefore offers us a unique opportunity to observe and study the processes of planet and satellite formation.'
While a clear disc was seen around the larger PDS 70c, there was no clear evidence of a disc surrounding the Saturn-like PDS 70b, suggesting it was 'starved' by its sister planet, which took the bulk of the dust remaining after the system formation.
This artist impression of the planet PDS 70c with its circumplanetary disc also shows what moon formation within the disc might look like, shown as a white dot on the right
This colourful image shows the sky around the faint orange dwarf star PDS 70 (in the middle of the image). The bright blue star to the right is χ Centauri.
ESO's Extremely Large Telescope (ELT), currently under construction in the Atacama desert, will provide even deeper insights into this planetary pairing.
Co author Dr Richard Teague, also from the CfA, said the ELT will be key for this research thanks to its much higher resolution allowing for more detailed mapping.
In particular, the team will look at the gas motions surrounding PDS 70c to get a full 3D picture of how the system interacts and how the moons come together.
The results have been published in The Astrophysical Journal Letters.
Deep in the Chilean desert, the Atacama Large Millimetre Array, or ALMA, is located in one of the driest places on Earth.
At an altitude of 16,400ft, roughly half the cruising height of a jumbo jet and almost four times the height of Ben Nevis, workers had to carry oxygen tanks to complete its construction.
Switched on in March 2013, it is the world's most powerful ground based telescope.
It is also the highest on the planet and, at almost £1 billion ($1.2 billion), one of the most expensive of its kind.
Deep in the Chilean desert, the Atacama Large Millimetre Array, or ALMA, is located in one of the driest places on Earth. Switched on in March 2013, it is the world's most powerful ground based telescope
The comments below have not been moderated.
The views expressed in the contents above are those of our users and do not necessarily reflect the views of MailOnline.
By posting your comment you agree to our house rules.
Do you want to automatically post your MailOnline comments to your Facebook Timeline?
Your comment will be posted to MailOnline as usual.
Do you want to automatically post your MailOnline comments to your Facebook Timeline?
Your comment will be posted to MailOnline as usual
We will automatically post your comment and a link to the news story to your Facebook timeline at the same time it is posted on MailOnline. To do this we will link your MailOnline account with your Facebook account. We’ll ask you to confirm this for your first post to Facebook.
Part of the Daily Mail, The Mail on Sunday & Metro Media Group
22 July, 2021 - 07:00am
Protoplanet PDS70c has a circumplanetary disk, according to new research published in The Astrophysical Journal Letters. Scientists thought as much in research published two years ago, but they weren’t able to distinguish the disk from its surrounding environment, leading to doubt. Follow-up observations made by the Atacama Large Millimetre/submillimeter Array (ALMA) in Chile were key to the confirmation.
“This system,” according to Stefano Facchini, a co-author of the paper and a research fellow at the European Southern Observatory, “offers us a unique opportunity to observe and study the processes of planet and satellite formation.”
Indeed, the confirmation of a circumplanetary disk around PDS70c could add new clarity to ongoing theories about exomoons and how they form. In one possible scenario, protoplanets steal mass from the surrounding circumstellar disk, and the resulting blobs of mass fall onto the forming planet. But some bits of matter stay in orbit, clumping together to form natural satellites.