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Astronomers find ‘homeless’ planet wandering through space

A planet that is not orbiting a star, effectively making it homeless, has been discovered by a team of University of Montreal (UdeM) researchers working with European colleagues and data provided by the Canada-France-Hawaii Telescope (CFHT) and the European Southern Observatory’s Very Large Telescope (VLT). “Although theorists had established the existence of this type of very cold and young planet, one had never been observed until today,” said Étienne Artigau, an astrophysicist at UdeM. The absence of a shining star in the vicinity of this planet enabled the team to study its atmosphere in great detail. This information will in turn enable astronomers to better understand exoplanets that do orbit stars.
Free-floating planets are planetary-mass objects that have no gravitational link to a star. “Over the past few years, several objects of this type have been identified, but their existence could not be established without scientific confirmation of their age,” explained Jonathan Gagné, a doctoral student of physics at UdeM. “Astronomers weren’t sure whether to categorize them as planets or as Brown dwarfs. Brown dwarfs are what we could call failed stars, as they never manage to initiate nuclear reactions in their centres.”
Gagné and Artigau, along with Lison Malo and Loïc Albert, all of whom are astrophysicists with UdeM and the Centre for Research in Astrophysics of Quebec (CRAQ), were able to find this planet with the assistance of French astronomers. Philippe Delorme, of the Laboratoire d’Astrophysique de l’Observatoire de Grenoble, was lead researcher. The planet is in fact called CFBDSIR2149 and appears to be part of a group of very young stars known as the AB Doradus Moving Group. “This group is unique in that it is made up of around thirty starts that all have the same age, have the same composition and that move together through space. It’s the link between the planet and AB Doradus that enabled us to deduce its age and classify it as a planet,” Malo explained.
First of all, the researchers obtained a series of infrared images of CFBDSIR2149 using the 3.6 metres in diameter CFHT. They then used the full strength of the 8 metres in diameter VLT to deduce its mass, its temperature, and of particular note, its age. The planet was found to be between 50 and 120 millions years old, with a temperature of approximately 400 degrees celsius, and a mass four to seven times that of Jupiter. Objects more than 13 times the mass of Jupiter are not considered to be planets but rather Brown dwarfs, as it is this is the minimum amount of mass required for the deuterium at the heart of a star to achieve fusion.
As an aside, it is interesting to note the significance of the finding in terms of the roots of the word “planet.” “Planet as a word originates from the Latin word planetus, which originally comes from the Greek words planeta or planêtês, meaning moving or wandering celestial bodies, as opposed to stars which appeared to be in a fixed position in the sky,” said Oliver Hernandez, an astrophysicist at UdeM.
In short, this is the first isolated planet – perhaps flung away during its formation – that is not tied by gravity to a star and whose mass, temperature and age meet the relevant criteria. This discovery, which has been sought after for more than a decade, supports theories relating to the formation of stars and planets. Moreover, it supports theories that suggest that these kinds of isolated objects are much more numerous than currently believed.
“This object was discovered during a scan that covered the equivalent of 1000 times the surface of the full moon,” Artigau explained. “We observed hundreds of millions of stars and planets, but we only found one homeless planet in our neighbourhood. Now we will be looking for them amongst an astronomical number of sources further afield. It’s like looking for a single needle in amongst thousands of haystacks.”

Space

Unusual signals come from the GJ 1151 system

Most likely, radio emission is created by the interaction of a planet the size of the Earth with the strong magnetic fields of its star.

Using the LOFAR low-frequency radio telescope, astronomers recorded unusual radio emission coming from the red dwarf GJ 1151, which is located at a distance of about 28 light-years from Earth, these signals, according to scientists, contain evidence of the auroras created by the interaction of the planet with the strongest magnetic fields of the star. The results of the study are presented in the journal Nature Astronomy.

“Radio emission from the interaction of a star and a planet was predicted more than thirty years ago, but only now we were able to identify its signature in the data. Success achieved paves the way for a new way to detect exoplanets in the habitable zone and study their surroundings, ”the authors of the study say.

Red dwarfs are the most common type of star in the Milky Way. They are much smaller and colder than the Sun and have extremely strong magnetic fields. This means that any potentially inhabited planet in the system of such a star, due to its proximity to it, is subjected to intense magnetic activity, which can heat it and even destroy the atmosphere. The radio emission associated with this process is one of the few tools available to evaluate this effect.

“The movement of the planet through the strong magnetic field of the red dwarf acts like an electric motor. This process generates a huge current that provokes radiance and creates radio emission, ”explained Harish Vedantam, lead author of the study from the Netherlands Institute of Radio Astronomy.

In the solar system, similar currents are not generated due to the weak magnetic field of the sun and the large distance to the planets. However, the interaction of the Io satellite with the magnetic field of Jupiter also creates a fairly bright radio emission, at low frequencies superior to the sun.

“We adapted our knowledge from decades of radio observations of Jupiter to the data on the star GJ 1151. For many years it was predicted that the Jupiter-Io system should exist in a larger version of the star-planet, and the radiation recorded by us from GJ 1151 is very well consistent with theory. Today we know that almost every red dwarf contains terrestrial planets, so there must be other stars showing such radiation,” Joe Cullingham added, the co-author of a study from the Netherlands Institute of Radio Astronomy.

Astronomers note that the sensitivity of modern instruments should allow them to find about a hundred more of such systems in the solar vicinity, and, more importantly, assess the conditions in which exoplanets reside in them.

“The main goal is to determine what effect the magnetic activity of a star has on the habitability of an exoplanet, and radio emission is the most important link in this puzzle,” Harish Vedantam concluded.

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Space

Mankind may face deadly viruses in search of new life in space

Professor Dov Greenbaum hypothesized that humanity’s search for signs of life outside the Earth could lead to an even greater threat of infection than a new kind of coronavirus.

In his material, the scientist notes that in the era of human mobility, new viruses spread very quickly, while bacteria grown in outer space can become even more deadly.

For a more detailed study of this issue, samples of genetically engineered bacteria samples are sent aboard the ISS. Despite the fact that the spread of extraterrestrial viruses in real life is considered a very unlikely scenario, the scientist warns against excessive optimism. The astrobiologist claims that dangerous viruses and infections can live in space on rocks that seem dead to the surface. In connection with these, Greenbaum believes that in the case of the reality of the existence of extraterrestrial life forms, their search without appropriate precautions “can lead to infections that will be even more dangerous and deadly than the acclaimed coronavirus.”

The professor also recalled that life was found in those places that were previously considered impossible for the existence of living organisms. So, NASA is going to deliver stones from the surface of Mars, and the Japanese space mission is already returning from the asteroid Ryugu with samples of its rock. At the end of this year, the Japanese Hayabusa2 will reach Earth. According to Greenbaum, it is likely that one of these missions will deliver a fundamentally new type of space infections to Earth.

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Space

Unknown carbon form found in Chelyabinsk meteorite

Scientists have discovered an unknown form of carbon on Earth in fragments of a meteorite that fell in the Chelyabinsk region in 2013, said Sergei Zamozdra, assistant professor of theoretical physics at the Chelyabinsk State University.

He said that the dean of the Faculty of Physics Sergey Taskaev (now the rector of the university. – Ed.), while studying samples of meteorite dust, noticed something amazing.

“At first he thought it was a diamond, because there were six faces. Later in Germany, this crystal was pulled out using micro-tweezers and when X-rayed – it turned out to be not a diamond, but a carbon crystal. We measured the position of atoms, the planes of interatomic, then Korean specialists on a computer calculated that, indeed, such an arrangement of atoms is possible, “he explained.

According to the scientist, carbon can have many modifications. However, such carbon has not yet been found on Earth, and experts will have to figure out how it came about, calculating different options.

“One option is that it arose in space conditions, because we are talking about a process of billions of years. Another is directly during a flight in the Earth’s atmosphere,” the scientist believes.

According to the press service of Chelyabinsk State University, the study of meteorite fragments was carried out by Sergey Taskaev together with colleagues from the Technical University of Darmstadt (Germany) and the National University of Kengpuk (Republic of Korea).

In the Chelyabinsk region on February 15, 2013, thousands of people watched a very bright object in the sky. In the first minutes, the expansion and twisting of its smoky plume was visible, followed by an air wave strike, similar to the sound of a strong explosion.

Fragments of the meteorite were found in the vicinity of Chebarkul, but the largest – more than 600 kilograms – was raised from the lake of the same name. Now it is stored in Chelyabinsk in the South Ural State Historical Museum under a special dome in the exhibition hall, where everyone can see it.

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