Tag Archives: winds

Astronomers report powerful winds of materials from central black hole in NGC 4945

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Astronomers using the Muse Instrument with ESO’s extremely large telescope (VLT) detected ultra-large black hole-driven winds with the Burred Spiral Galaxy NGC 4945.

This image shows NGC 4945, a spiral galaxy that exceeds 12 million light-years in the constellation of Centaurus. The super-large black hole-driven wind of the NGC 4945 is shown in red in the inset. Image credits: ESO/Marconcini et al.

NGC 4945 It is more than 12 million light years away from Earth, the constellation of Centaurus.

Otherwise known as the Caldwell 83. That’s what this galaxy was like I discovered it by James Dunlop, the Sottsch astronomer in 1826.

NGC 4945 hosts one of the closest active, ultra-large black holes to Earth.

“At the heart of almost every galaxy, they are very large black holes,” the ESO astronomer explained in a statement.

“Some people are not particularly hungry, as they are in the heart of our own Milky Way.”

“However, the super-large black hole in NGC 4945 is greedy and consumes a huge amount of problems.”

Astronomers have studied the ultra-high Massive black holes of the NGC 4945 using the Muse Instrument, an ESO’s extremely large telescope (VLT).

“Contrary to the all-consuming reputation typical of black holes, this messy eater is blowing away the powerful winds of ingredients,” they said.

“This cone-shaped wind is shown in red in the inset and is covered in a wider image taken with La Silla’s MPG/ESO telescope.”

“In fact, this wind moves so fast that it completely escapes the galaxy, giving in to space in intergalactic space.”

“This is part of a new study measuring how the wind moves in several nearby galaxies,” they added.

“Muse’s observations show that these incredibly fast winds show strange behavior. They actually speed up far from the central black hole, and accelerate even further on their journey to the outskirts of the galaxy.”

“This process suggests that black holes control the fate of the host galaxy by ejecting potential star-forming material from the galaxy and attenuating the star’s fertility.”

“It also shows that more powerful black holes can hamper their own growth by removing the gas and dust they feed, bringing the entire system closer to a kind of galactic equilibrium.”

“Now, these new results bring us one step closer to understanding the mechanisms of wind acceleration that are responsible for galaxy evolution and the history of the universe.”

Survey results It will be displayed in the journal Natural Astronomy.

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C. Marconcini et al. Evidence of rapid acceleration of AGN-driven winds at the Kiloparsec scale. Nut Athlonreleased on March 31, 2025. doi:10.1038/s41550-025-02518-6

Source: www.sci.news

Winds on the alien planet reach speeds of 33,000 kilometers per hour

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Artist’s visualization of the gas giant WASP-127b

ESO/L.Calzada

The vast alien planet has fierce winds blowing around its equator at nearly 30 times the speed of sound on Earth.

Lisa Nortman He and his colleagues at the University of Göttingen in Germany used the European Southern Observatory’s Very Large Telescope in Chile to observe WASP-127b, a gas giant exoplanet more than 500 light-years from Earth. Although slightly larger than Jupiter, it is one of the least dense planets we know of.

The researchers expected the light signal from the planet’s atmosphere to have one distinct peak, but instead they found two distinct peaks.

“It was a little confusing,” Nortman says. “But when we analyzed the data a little more carefully, it became clear that there were two signals. I was very excited – my first thought was that it must be some kind of super-rotating wind. I thought that right away.”

The researchers concluded that the two mountains were caused by rapid winds from the jet stream near the equator, with half of the wind moving toward Earth and the other half moving away from it. The wind appears to be made up of water and carbon monoxide, and appears to be moving at 33,000 kilometers per hour, the fastest wind ever measured on Earth.

“We’re talking about nine kilometers per second. Even Jupiter’s wind speeds are on the order of a few hundred meters per second, so this is actually an order of magnitude bigger.” vivian parmentier at Oxford University.

He says that if you were in this wind, you wouldn’t be able to feel such extreme speeds because it would be moving around you at the same speed. But because the wind moves from the hot side of the Earth, which is always facing the star, to the cold side, which is always in darkness, you will experience a temperature difference of several hundred degrees in a few hours.

Researchers don’t know why WASP-127b has such extreme winds, but Nortman said the planet has certain peculiarities, including a low density and an unstable orbit around its star. It is said that there are certain characteristics that may play a role. “However, no clear connection has been established between those facts and particularly strong winds.”

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Source: www.newscientist.com

Report finds that Hurricane Helen had increased rainfall and stronger winds as a result of climate change

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Samamuri

  • Climate change has increased Hurricane Helen’s wind speed by 11% and total precipitation by about 10%, according to a new report.
  • Researchers expect Milton to do the same, and say it is likely to get worse because of climate change.
  • The report says the higher sea surface temperatures that contributed to the intensification of both storms are 200 to 500 times more likely to be due to climate change.

As Hurricane Milton hurtles toward Florida’s west coast, a new report estimates how intense Hurricane Helen’s winds and rain could have been due to climate change. Scientists involved in the study said they expected Milton to do the same, and that it would likely get worse because of climate change.

The report, released late Wednesday night, is from the World Weather Attribution Group, a consortium of scientists that analyzes extreme weather events and determines how much climate change has influenced certain events. He is regarded as the leading expert in making decisions.

The findings show that because of climate change, Hurricane Helen’s wind speeds were 11% more intense and its precipitation totals were about 10% higher.

Friederike Otto, a climate scientist at Imperial College London who contributed to the new study, said “we now have a complete study showing a very clear link” between climate change and hurricane strength. “The biggest danger is not making the connection to climate change.”

Like Hurricane Helen, Hurricane Milton is also moving through record-breaking heat. Sea surface temperatures in the Gulf of Mexico are much warmer than usual, even for this time of year. Warmer water acts as fuel for such storms, helping them intensify faster.

Both hurricanes undergo a process known as rapid intensification, where the hurricane’s sustained wind speeds increase by at least 35 miles per hour over a 24-hour period. This trend is becoming more common due to climate change.

The report says the sea surface temperatures that pushed Helen and Milton up were 200 to 500 times warmer due to climate change.

On Monday, Milton experienced a dramatic pressure drop in the center of the hurricane, strengthening to one of the fifth strongest hurricanes ever recorded.

“This storm is definitely explosive,” said Bernadette Woods Plucky, chief meteorologist at the nonprofit research group Climate Central and co-author of the new report.

Using a combination of statistical analysis and detailed climate modeling, the researchers found that climate change and the fossil fuel pollution it causes are about 2.5 times more likely to produce a hurricane as strong as Helen.

This is the third and most extensive preliminary report linking climate change to the heavy rains that killed more than 200 people after Hurricane Helen made landfall in Florida’s Big Bend region on September 26.

Scientists at World Weather Attribution examined rainfall over two days along the coast of Florida, where Helen first hit, and three days of rainfall in mountainous areas in six neighboring states, including North Carolina and Tennessee. Assessed quantity.

They found that coastal rainfall totals are 40% more likely to be this high due to climate change, and inland rainfall totals are 70% more likely to be this high due to climate change. I discovered that there is a sex.

Helen flooded parts of southern Appalachia with more than 6 feet of rain. Floodwaters washed away houses, washed out highways, and cut off access to the town. Much of the recovery work is just beginning.

Damaged buildings in downtown Chimney Rock, North Carolina, after Hurricane Helen passed through on October 2nd.
Alison Joyce/AFP via Getty Images

The World Weather Attribution group is a loose confederation of scientists who rapidly publish extreme findings about whether and how climate change has affected particular events. Twenty-one researchers participated in the new analysis. Although the group uses peer-review methods, its findings are published prior to traditional peer-review when events are new and particularly newsworthy. Previous studies on global weather attribution have withstood further scrutiny by outside scientists and been published in major scientific journals.

Otto said the new results are consistent with two previous analyzes of the effects of climate change on Hurricane Helen, but different researchers defined the parameters of the study in different ways, and there are different He said each report produced different numbers because they focused on geography.

Scientists at World Weather Attribution will run the numbers again for Milton and write a new report.

Source: www.nbcnews.com

Strong winds have the power to generate massive waves, scientists reveal

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A rogue wave is a single swell that is much higher than nearby waves and can cause damage to ships and coastal infrastructure. Ocean waves are one of the most powerful natural forces on Earth, and they could become even more powerful as global trends suggest ocean winds will blow even stronger with climate change. there is. Scientists at the University of Melbourne have discovered in a new study that rogue waves are generated by strong winds and unpredictable wave patterns, confirming an idea previously only proven in the lab.

Toffoli other.We report direct observations of surface waves from a stereo camera system and simultaneous measurements of wind speed during an expedition across the Southern Ocean during the Antarctic winter aboard a South African icebreaker. SA Agulhas II. Image credit: Alessandro Toffoli.

“Rogue waves are huge, twice as tall as nearby waves, and appear out of nowhere,” said University of Melbourne’s Professor Alessandro Toffoli, lead author of the study.

Using cutting-edge technology and embarking on an expedition to one of the most unstable ocean regions on Earth, Professor Toffoli and colleagues have introduced a new technique for 3D imaging of ocean waves.

Operating a stereo camera on a South African icebreaker SA Agulhas II During their 2017 Antarctic expedition, they captured valuable insights into the behavior of waves in this remote region.

Their method, which mimics human vision through continuous imaging, allowed researchers to reconstruct the wavy ocean surface in three dimensions, providing unprecedented clarity into ocean wave dynamics. Ta.

The first scientific measurement of a rogue wave was the 25.6 m Draupner wave recorded in the North Sea in 1995. Since the beginning of the 21st century, 16 cases of suspected rogue waves have been reported to him.

“Scientists have long theorized that Antarctica’s rough seas and fierce winds can cause large waves to ‘self-amplify’, resulting in rogue wave frequencies. “However, this has not yet been tested underwater,” Professor Toffoli said.

The team’s observations, using numerical and laboratory studies that suggested the role of wind in the formation of rogue waves, provided validation of these theories in a real marine environment.

“Our observations show that unique sea conditions with rough waves occur during the ‘young’ stage of the waves, when they are most susceptible to wind effects. This suggests that wind parameters are the missing link,” Professor Toffoli said.

“Wind creates a chaotic situation where waves of different dimensions and directions coexist.”

“The wind causes young waves to grow higher, longer and faster.”

“During this self-amplification, waves grow disproportionately at the expense of neighboring waves.”

“We show that young waves are showing signs of self-amplification and are likely to be wind-driven.”

“Once every six hours, we recorded waves that were twice as high as nearby waves.”

“This reflects laboratory models. The theory is that sea conditions are more likely to self-amplify, creating more rogue waves.”

“In contrast, no rough waves were detected in mature oceans that are not influenced by winds.”

The authors highlight the critical importance of integrating wind dynamics into predictive models for rough sea prediction.

“This shows that scientists need to take wind into account thoroughly when developing tools to predict rogue waves,” Professor Toffoli said.

of findings It was published in the magazine physical review letter.

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A. Toffoli other. 2024. Observation of the bad waters of the Southern Ocean. Physics.pastor rhett 132 (15): 154101; doi: 10.1103/PhysRevLett.132.154101

Source: www.sci.news

The Threat of Cool Star’s Strong Winds to Exoplanets

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Artist’s illustration of a stellar planetary system. You can clearly see the stellar wind orbiting the star and its effect on the planet’s atmosphere.Credit: AIP/ K. Riebe/ J. Fohlmeister, editor

A groundbreaking study reveals that cold stars with strong magnetic fields generate powerful stellar winds, providing important information for assessing the habitability of exoplanetary systems.

A study led by scientists at the Potsdam Leibniz Institute for Astrophysics (AIP) uses cutting-edge numerical simulations to systematically characterize the properties of stellar winds in a sample of cold stars for the first time. Ta. They found that stars with stronger magnetic fields generate stronger winds. These winds create unfavorable conditions for the survival of planetary atmospheres, thus affecting the habitability of these systems.

Cool star classification

The Sun is one of the most abundant stars in the universe, known as “cool stars.” These stars are divided into four categories (F-type, G-type, K-type, and M-type) that differ in size, temperature, and brightness. The Sun is a fairly average star and belongs to category G. Stars that are brighter and larger than the Sun belong to category F, while K stars are slightly smaller and cooler than the Sun. The smallest and faintest star is the M star, also known as a “red dwarf” because of the color in which it emits most of its light.

Solar wind and its effects

Satellite observations have revealed that, apart from light, the sun continuously emits a stream of particles known as the solar wind. These winds travel through interplanetary space and interact with the planets of our solar system, including Earth. The beautiful displays of the Northern Lights near the North and South Poles are actually produced by this interaction. But these winds can also be harmful, as they can erode Earth’s stable atmosphere. Mars.

We know a lot about the solar wind, thanks in part to missions like Solar Orbiter, but the same isn’t true for other cool stars. The problem is that we can’t see these stellar winds directly, so we’re limited to studying their effects on the thin gas that fills the cavities between stars in galaxies. However, this approach has some limitations and can only be applied to a small number of stars. This has encouraged the use of computer simulations and models to predict various properties of stellar winds without the need for astronomer observations.

Pioneering research on the properties of stellar winds

In this regard, in collaboration with Cecilia Garaffo of the Harvard University Center for Astrophysics, doctoral student Judy Chevely of AIP’s Stellar Physics and Exoplanet Division, and scientist Julián D. Alvarado Gomez Dr. Katja Poppenhager, head of the department, assisted. The Smithsonian Institution conducted the first systematic study of the expected stellar wind properties for F, G, K, and M stars.

To this end, they performed numerical simulations using one of the most sophisticated models currently available, driven by the observed large-scale magnetic field distributions of 21 well-observed stars. I used it. The simulations were performed at the AIP and Leibniz-Rechenzentrum (LRZ) supercomputing facilities.

The research team investigated how star properties such as gravity, magnetic field strength, and rotation period affect the properties of the wind in terms of velocity and density. The results include a comprehensive characterization of stellar wind properties across spectral types and, in particular, challenge previous assumptions about stellar wind speeds when estimating associated mass loss rates from observations. This indicates that it needs to be reconsidered.

In addition, the simulations can predict the expected size of the Alfvén surface, the boundary between the stellar corona and the stellar wind. This information is the basis for determining whether planetary systems are affected by strong magnetic star-planet interactions. This interaction can occur when a planet’s orbit enters or is completely embedded in the Alfvén surface of its host star.

Impact on planetary systems

Their findings show that stars with magnetic fields larger than the Sun have faster winds. In some cases, stellar wind speeds can be up to five times faster than the average solar wind speed (typically 450 km/s). The study revealed how strong these stars’ winds are in their so-called “habitable zone,” defined as the orbital distance at which a rocky exoplanet can maintain liquid water on its surface and provide an Earth-like atmospheric pressure. It was evaluated as being strong. They found milder conditions around F- and G-type stars, comparable to those experienced by Earth around the G-type Sun, and increasingly harsh wind environments around K- and M-type stars. discovered. Such intense stellar winds have a strong impact on any atmosphere a planet might have.

Broader implications for exoplanet research

This phenomenon is well documented in heliophysics between rocky planets and the Sun, but not in exoplanetary systems. This requires estimates of stellar winds to assess processes similar to those seen between the solar wind and planetary atmospheres. This study is important from the perspective of habitability, as no information on stellar winds has been known for main-sequence stars F to M until now.

Although the study presented in this paper was performed on 21 stars, the results are general enough to apply to other cool main sequence stars. This study paves the way for future studies of stellar wind observations and their effects on planetary atmosphere erosion.

References: Judy J Chebly, Julián D Alvarado-Gómez, Katja Poppenhäger, and Cecilia Garraffo, “Quantifying the wind properties of cool main-sequence stars,” July 19, 2023. Royal Astronomical Society Monthly Notices.
DOI: 10.1093/mnras/stad2100

Source: scitechdaily.com