Connect with us

Space

The Closest Star to Our Solar System Has Suffered an Insane Eruption

Our closest stellar neighbour, Proxima Centauri, knows how to belch ’em out. According to new research, in March of last year it erupted into an absolute beast of a stellar flare, 10 times brighter than the largest flares produced by our own Sun, even though it has only about one-eighth of the mass.

This puts a damper on the notion that the red dwarf is being orbited by a plethora of planets, as was determined by a team of researchers last year.

Based on a reanalysis of the same data, it now looks like there’s no dust ring after all, as previously thought.

In November last year, researchers from the Institute of Astrophysics of Andalusia (IAA) in Spain announced that they’d detected a glow coming from Proxima Centauri.

They attributed this glow to a ring of dust, like the asteroid belt orbiting the Sun on the far side of Mars, or the Kuiper belt out past Pluto.

This, they believed, could indicate the presence of an entire planetary system orbiting outside the exoplanet Proxima b, which had been confirmed in 2016.

This is because dust and asteroid belts are leftover from the accretion disc of dust that swirls around a forming star, and which can result in the formation of planets.

According to a team of researchers led by Carnegie’s Meredith MacGregor, this interpretation of the data now appears flawed.

The extra light detected by the IAA researchers, their new analysis suggests, wasn’t reflected light from a dust ring, but the result of a massive solar flare.

So how did the two teams arrive at such different conclusions based on the same data?

Both teams looked at 10 hours of data captured by the Atacama Large Millimeter/submillimeter Array, a radio telescope comprising 66 antennas, taken from 21 January through 25 April 2017.

The IAA team based its finding on the average amount of light over those three months, including the light of the star and the flare together to result in the dust cloud interpretation.

MacGregor’s team, on the other hand, did not average out the data, but analysed it as a function of observing time – resulting in a spike in the star’s emission.

On 24 March, 2017, they found, the star erupted into an absolutely massive solar flare – 1,000 times brighter than the star’s normal emissions, over a period of 10 seconds.

Overall, the event lasted less than two minutes.

We know Proxima Centauri has a great deal of flare activity, so this wouldn’t be entirely out of character for the star. But it also lowers the chances for finding life on Proxima b, a rocky planet about 1.3 times the mass of Earth.

Because the star is so cool and dim, the planet has to orbit very close to the star in order to be within the habitable zone. This means that it’s much more likely to get lashed by stellar flares, which could strip away its atmosphere, if it even had one to start with.

“It’s likely that Proxima b was blasted by high energy radiation during this flare,” MacGregor said.

“Over the billions of years since Proxima b formed, flares like this one could have evaporated any atmosphere or ocean and sterilised the surface, suggesting that habitability may involve more than just being the right distance from the host star to have liquid water.”

That doesn’t mean all hope is lost, however. There may still be planets orbiting Proxima Centauri that we can’t see.

In fact, we can’t even see Proxima b either. It was found back in 2015 using Doppler spectroscopy, which confirms planets based on the very small changes in light when a star moves towards or away from us, tugged by the gravitational pull of an orbiting body.

Because we can’t see the planet directly, any other planets on the same orbital plane would likewise be invisible. But, so far, there has been no indication that there are any more planets, especially now that the dust cloud finding has been called into significant doubt.

“There is now no reason to think that there is a substantial amount of dust around Proxima Cen[tauri],” said co-author Alycia Weinberger of Carnegie.

“Nor is there any information yet that indicates the star has a rich planetary system like ours.”

We’ll just have to keep looking.

The team’s paper has been published in The Astrophysical Journal Letters, and can be read in full on arXiv.

Read More On This At ScienceAlert – Latest

Comments

Space

Mars water may have been excellent for life

Mars water appears to have been an especially good element for life, according to a new study.

Mars water may have been excellent for life
An illustration of what Mars would look like without and with water. PHOTO: JAMES MOORE

Mars is one of the most likely homes for alien life in our solar system, and water is believed to be an essential requirement for life, as we know it, to be maintained.

Previous studies have suggested that the red planet would have once been home to flowing water lakes, which could have harbored life.

But there is still no evidence to suggest that alien life lived on the planet – or that there is still some evidence of it.

In an attempt to understand what Mars would look like in ancient times and whether it was inhabited, scientists sought to understand the chemistry of water that would be found on the planet billions of years ago.

They did so by looking at the materials left on that planet today, which could offer a clue to what it was like before.

Recent measurements taken by the probe jeep Curiosity from NASA on the Martian surface suggest that the water that once covered its surface could have the right ingredients to support any microbial life that would have formed on the planet.

The new study looked at sediments that appeared to have been left in lakes in the Gale de Mars Crater. He found that they appeared to form in the presence of liquid water with a pH similar to that of Earth’s oceans.

This suggests that the initial surface of Mars would have been the kind of place that could have served as a home for life, like Earth.

An article detailing the discovery, entitled ‘Semiarid climate and hyposaline lake on early Mars inferred from reconstructed water chemistry at Gale‘(‘ Semi-arid climate and hyposaline lake in early Mars inferred from reconstructed water chemistry in Gale ’), was published in Nature Communications.

Source

Continue Reading

Space

Some potentially inhabited worlds may not have “zones of life”

An artistic representation of a tidal trapped potentially inhabited exoplanet, with the open ocean of liquid water surrounded by a global ice shell covering the rest of the extra-solar world on the day side.

They may be completely covered in ice and their oceans do not receive starlight.

Some of the potentially inhabited exoplanets orbiting red dwarfs may be completely covered in ice and not have open surface oceans of liquid water even on the side facing the star, which, under certain conditions, makes them unsuitable for life, scientists say in a study presented in Nature Astronomy.

planet

“Perhaps some of the tidal traps of extrasolar worlds that were previously considered potentially inhabitable are frozen snowballs and have no open areas with liquid water. As a result, the starlight necessary for photosynthetic organisms does not reach the ocean, sealed under a global ice shell, which greatly limits the chances of the development and prosperity of life, ”says Jun Yan, lead author of the study from Peking University (China).

Potentially inhabited tidal rocky extra-solar worlds in red dwarf systems, especially the Proxima b, TRAPPIST-1e, and LHS 1140b, which are especially close to us, are the main goals for future studies of exoplanetary atmospheres, which can provide clues about their ability to support life.

planet

Current models predict that if such a planet contains a vast surface ocean, then on its warmer day side there should be an ice-free area, locked on all sides by a global ice shell. However, as noted by Jun Yan, previous simulations did not fully take into account the important component of the climate system – ice dynamics – which did not allow revealing the issue of ocean resilience to global glaciation.

“In our work, we show that ice drifting from the night side of the exoplanet flows into an open area, gradually cooling, reducing, and ultimately completely sealing it.

It should be noted that such a scenario is applicable only to worlds living in the outer and, possibly, in the middle regions of the inhabited zone, but not to those located at its inner edge, since for them the flux of stellar radiation is high enough to melt ice and snow on the surface and maintain liquid water on the day and even night sides. In addition, the presence of greenhouse gases in the atmosphere plays a small role, since a large number of them will save the exoplanet from turning into a snowball, ”Jun Yan explained.

But, in spite of the fact that planets completely covered with ice are extremely inhospitable for life, one should not put an end to their potential for habitability, because the Earth itself in the past twice experienced periods of global glaciation: 2.2 billion years ago and 630 million years ago.

“For example, photosynthetic organisms can develop in areas with thin ice, where stellar radiation nevertheless reaches liquid water, or in local unsealed areas where active geothermal processes occur, or, finally, in some“ bays, ”where access to drifting ice is limited.” – concluded Jun Yan.

Continue Reading

Space

Betelgeuse star continues to fade, preparing for an explosion

Betelgeuse continues to fade, but is the light preparing to break out a supernova, or are some other processes leading to this?

Betelgeuse
© universetoday.com

Astronomers from Villanova University Edward Ginan and Richard Wasatonic were the first scientists to report Betelgeuse tarnishing. Now they are reporting that the brightness of the star continues to decline.

Recall that Betelgeuse is a red-orange super-giant pulsating star in the constellation Orion, which is 700 light-years distant from Earth. At the end of it’s life, Betelgeuse will explode a supernova, and probably this has already happened.

It is important to note that Betelgeuse is a variable star, which means its brightness is a variable.

Astronomers are well aware of this and have long observed the brightness change cycles. Most fluctuations are predictable, but what happens to Betelgeuse today is an anomaly.

The star became fainter than ever in the history of observations.

According to information provided by Ginan and Vasatonic, the temperature of Betelgeuse over 3 months fell by almost 173 degrees Celsius, and its brightness fell by 25%. At the same time, the radius of the object grew by about 9%.

Betelgeuse star continues to fade, preparing for an explosion
Each circle is a separate observer (telescope, spacecraft) for Betelgeuse, recording changes in luminosity. The fall in brightness at the beginning of 2020 can be seen very well on the right in the image (© universetoday.com)

We are very lucky that, by the standards of the Universe, Betelgeuse is so close to us. We can observe the evolutionary process of another star and collect such detailed data.

Betelgeuse flashed a supernova?

Probably. However, scientists are considering any other options and do not want to focus only on this conclusion.

They assume that a decrease in brightness could cause a gas-dust cloud flying between us and Betelgeuse. By the way, it could also explain the temperature drop. What to do with the growth of the radius? It is possible that this is simply “age-related edema” caused by a natural evolutionary process.

There is a possibility that Betelgeuse has already flashed a supernova or that we are observing its unstable behavior before this event, which will be the most spectacular natural disaster available to humans.

Supernova explosion
© wikipedia.org

Yes, astronomers observed supernovae such as SN 185 and SN 1604, but they were extremely far from Earth, so no details were even discussed.

When Betelgeuse explodes (or has already exploded), this event will become the third brightest object in the earth’s sky after the Sun and the full Moon. By some estimates, it will be even brighter than the moon!

This glow will persist for months or even years, casting a shadow on Earth at night. After about 3 years, this colossal brightness will disappear, and after 6 years there will be no trace in the night sky.

When will this happen?

Astronomers know what will happen, but they don’t know when exactly, answering something like: “yesterday, tomorrow or in a century.”

Continue Reading
Advertisement

DO NOT MISS

Trending