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When NASA found the first ever ‘Ultrahot Neptune’

LOSING MY ATMOSPHERE  Astronomers think “hot Jupiter” exoplanets could lose their atmospheres as they draw close to their stars (as shown in this illustration), leaving scorched rocky worlds. The TESS telescope may have caught this transition in the act.

 Astronomers have spotted a new kind of planet: a Neptune-sized world sitting scorchingly close to its star. 

Astronomers have found a very hot planet, has the same size as that of a Planet Neptune.

It could be in the midst of transforming from a hot, puffy gas giant to a naked rocky core, astronomer James Jenkins reported July 29, 2019 at the TESS Science Conference at MIT.

“This planet is amazing. It’s the first of its kind,” says astronomer Elisabeth Adams of the Planetary Science Institute, who is based in Somerville, Mass. Adams studies larger planets that orbit close to their stars but weren’t involved in the discovery.

The planet is named LTT 9779b, orbits a star which is similar to our sun, and it’s about 260 light-years away. It was discovered by NASA’s Transiting Exoplanet Survey Satellite or TESS. The Satellite was launched in April 2018. 

Data collected by TESS show that the planet swings around its star once every 19 hours, putting it in a rare class of planets that orbit incredibly close to their stars.

Most other planets with such close orbits are either Earth-sized or Jupiter-sized and larger, said Jenkins, of the University of Chile in Santiago. But LTT 9779b is 4.6 times Earth’s size and 29.3 times Earth’s mass, placing it right in the middle of those extremes. Its proximity to its star should heat it to about 2000 kelvins (about 1725° Celsius), making it the first known ultrahot Neptune, Jenkins said.

One explanation for how close-in planets get cozy with their stars is that the worlds (Planets) form farther away and migrate closer over time. A planet that had a thick, gaseous atmosphere might lose more and more of that gas the closer it comes to its star, as the heat evaporates the atmosphere or the star’s gravity steals the gas away.

At about 2.5 million kilometers from its star, LTT 9779b may be about the closest a planet can physically get before the star gobbles up all of the atmospheres. If so, it could be a bridge between exoplanets called hot Jupiters, which are gas giants like Jupiter but have many closer-in orbits, and smaller, scorched rocky worlds, Jenkins suggested. The new planet is much smaller than a hot Jupiter, but still has a thick atmosphere that makes up about 9 percent of its mass, he said. 

The next step is to measure how quickly LTT 9779b is losing mass, Adams says. If it’s rapid, that could explain why no other ultrahot Neptunes have been discovered: They shift from gas giant to rocky core too quickly. Finding one mid-transition may have been a stroke of luck.

Physicists spot a new class of neutrinos from the sun

Neutrinos from the sun’s second-most prominent nuclear fusion process have been spotted in the Borexino detector (inside shown with light-detecting sensors).

Neutrinos spit out by the main processes that power the sun are finally accounted for, physicists report.

Similar to an electron a Neutrino is a subatomic particle but Unlike an electron, it has no electrical charge. The mass of a neutrino is also very small, which might be even zero.

Neutrinos are one of the most abundant subatomic particles in the universe because they don’t have much interaction with the matters.

Two sets of nuclear fusion reactions predominate in the sun’s core and both produce the lightweight subatomic particles in abundance.

Scientists had previously detected neutrinos from the most prevalent process. Now, for the first time, neutrinos from the second set of reactions have been spotted, researchers with the Borexino experiment said June 23 in a talk at the Neutrinos 2020 virtual meeting.

“With this outcome, Borexino has completely unraveled the two processes powering the sun,” said physicist Gioacchino Ranucci of Italy’s National Institute for Nuclear Physics in Milan.

In the sun’s core, hydrogen fuses into helium in two ways. One, known as the proton-proton chain, is the source of about 99 percent of the star’s energy. The other group of fusion reactions is the CNO cycle, for carbon, nitrogen, and oxygen — elements that allow the reactions to proceed. Borexino had previously spotted neutrinos from the proton-proton chain. But until now, neutrinos from the CNO cycle were MIA.

“They’re top of everybody’s list to try and identify and to spot,” says physicist Malcolm Fairbairn of King’s College London. “Now they think they’ve spotted them, which is a major achievement, really an extremely difficult measurement to make.”

Located deep underground at the Gran Sasso National Laboratory in Italy, Borexino searches for flashes of light produced as neutrinos knock into electrons in a large vat of liquid. Researchers have spent years fine-tuning the experiment to detect the elusive neutrinos that herald the CNO cycle. Although difficult to observe, the particles are plentiful, Borexino confirmed. On Earth, around 700 million neutrinos from the sun’s CNO cycle pass through a square centimeter each second, the researchers report.

The result, presented for the first time at the virtual meeting, must still clear the hurdle of peer review in a scientific journal before it is fully official.

The property that reveals the abundance of elements present in an object that are heavier than hydrogen and helium is known as Metallicity property. Studying these particles could help reveal how much of the sun is composed of elements heavier than hydrogen and helium. That’s because the rate at which CNO cycle neutrinos are produced depends on the sun’s content of carbon, nitrogen, and oxygen. Different types of measurements currently disagree about the sun’s metallicity, with one technique suggesting higher metallicity than another.

In the future, more sensitive measurements of CNO neutrinos could help scientists disentangle the problem.

The CNO cycle is even more important in stars heavier than the sun, where it is the main fusion process. Studying this cycle in the sun can help physicists understand the inner workings of other stars, says Zara Bagdasarian, a physicist at the University of California, Berkeley, and a member of the Borexino Collaboration. “It’s very important for us to understand how the sun works.”

The youngest baby star in the universe

We all like to gaze up at the sky during the night. Some even try to count them. You may calculate them in your test paper or rate a hotel based on stars, but there are many, and it won’t be possible to count them. According to an estimation, there are more than 9000 visible stars in the sky and around 100 thousand million stars in the Milky Way Galaxy and more in the entire universe.

A neutron star was found and made it on the list when it was nearly 240 years old. Yes, that’s the youngest star, a neutron star to be precise. But what does it mean? Neutron, by the name, consists of 95 percent neutron, which is indeed made from protons, releasing the particles called neutrinos. There’s a lot more to know about in the world of astronomy. These neutron stars have a mass nearly 1.4 times compared to the sun.

A supernova in the galaxy.

These originate after the death of another giant star and form newer stars. There are many types of neutron stars, and the recently found one is a magnetar. Magnetar usually has a powerful magnetic field. The field can be so strong, about a hundred million times stronger than the most potent magnets on Earth made by the humans, and it can manipulate the shape of an atom. These magnetars can remain active for around ten thousand years, considered as a short time in cosmic history.

You may have heard about supernova. The neutron star is created due to the same supernova, as mentioned above earlier. There are more than 3000 neutron stars, and researchers know only 31 magnetars. The magnetar discovered is named Swift J1818.0-1607 on 12th March this year 2020, along with a substantial amount of X-rays, gamma rays, and stable beams of radio waves. This star was noticed at NASA’s Neil Gehrels Swift Observatory.

The actual image of Swift J1818.0−1607. Courtesy : NASA

The star is a part of the Sagittarius constellation and 16000 light-years away, making it somewhat close to Earth when compared to other stars. Do you know the nearest star to the planet Earth is Alpha Centauri, which is about 4.3 light-years away? The neutron stars can be merely 15 km to 30 km wide, and it can turn around once every 1.36 seconds, one of the fastest-spinning matters. This star also falls in a category known as radio pulsars, and the magnetar is one of the five radio pulsars ever discovered.

An illustration of a magnetar. Courtesy: EAS

There is very little information about these categories, and this single discovery can help in learning about its formation, aging, and its existence. This discovery was made when there was an outburst at that moment. So some findings may occur unknowingly; the researchers wished if they could see from its existence. This star was observed when the X-ray emissions were at the peak, making it ten times shinier than usual as the magnetar was out-bursting. Some inventions may happen accidentally but may make a significant change to humankind. Let me describe with an example: the discovery of penicillin was made by Alexander Fleming in 1928 when he had returned from a vacation.