New tool to check spread of fake news developed

Paris, Jul 2: Several interacting exoplanets have already been spotted by satellites. But a new breakthrough has been achieved with, for the first time, the detection directly from the ground of an extrasolar system of this type.

An international collaboration including CNRS researchers has discovered an unusual planetary system, dubbed WASP-148, using the French instrument SOPHIE at the Observatoire de Haute-Provence (CNRS/Aix-Marseille Universite).

The scientists analysed the star's motion and concluded that it hosted two planets, WASP-148b and WASP-148c. The observations showed that the two planets were strongly interacting, which was confirmed from other data.

Whereas the first planet, WASP-148b, orbits its star in nearly nine days, the second one, WASP-148c, takes four times longer. This ratio between the orbital periods implies that the WASP-148 system is close to resonance, meaning that there is enhanced gravitational interaction between the two planets. And it turns out that the astronomers did indeed detect variations in the orbital periods of the planets.

While a single planet, uninfluenced by a second one, would move with a constant period, WASP-148b and WASP-148c undergo acceleration and deceleration that provides evidence of their interaction.

The study will shortly be published in the journal Astronomy & Astrophysics.

Washington DC, Jun 8: Astronomers acting on a hunch have likely resolved a mystery about young, still-forming stars and regions rich in organic molecules closely surrounding some of them.

They used the National Science Foundation's Karl G Jansky Very Large Array (VLA) to reveal one such region that previously had eluded detection and that revelation answered a longstanding question.

The regions around the young protostars contain complex organic molecules which can further combine into prebiotic molecules that are the first steps on the road to life.

The regions, dubbed "hot corinos" by astronomers, are typically about the size of our solar system and are much warmer than their surroundings, though still quite cold by terrestrial standards.

The first hot corino was discovered in 2003 and only about a dozen have been found so far. Most of these are in binary systems, with two protostars forming simultaneously.

Astronomers have been puzzled by the fact that, in some of these binary systems, they found evidence for a hot corino around one of the protostars but not the other.

"Since the two stars are forming from the same molecular cloud and at the same time, it seemed strange that one would be surrounded by a dense region of complex organic molecules and the other wouldn't," said Cecilia Ceccarelli, of the Institute for Planetary Sciences and Astrophysics at the University of Grenoble (IPAG) in France.

The complex organic molecules were found by detecting specific radio frequencies, called spectral lines, emitted by the molecules. Those characteristic radio frequencies serve as "fingerprints" to identify the chemicals.

The astronomers noted that all the chemicals found in hot corinos had been found by detecting these "fingerprints" at radio frequencies corresponding to wavelengths of only a few millimetres.

"We know that dust blocks those wavelengths, so we decided to look for evidence of these chemicals at longer wavelengths that can easily pass through dust," said Claire Chandler of the National Radio Astronomy Observatory, and principal investigator on the project.

"It struck us that dust might be what was preventing us from detecting the molecules in one of the twin protostars," added Chandler.

The astronomers used the VLA to observe a pair of protostars called IRAS 4A, in a star-forming region about 1,000 light-years from Earth. They observed the pair at wavelengths of centimetres.

At those wavelengths, they sought radio emissions from methanol, CH3OH (wood alcohol, not for drinking). This was a pair in which one protostar clearly had a hot corino and the other did not, as seen using the much shorter wavelengths.

The result confirmed their hunch. "With the VLA, both protostars showed strong evidence of methanol surrounding them. This means that both protostars have hot corinos. The reason we did not see the one at shorter wavelengths was because of dust," said Marta de Simone, a graduate student at IPAG who led the data analysis for this object.

The astronomers cautioned that while both hot corinos now are known to contain methanol, there still may be some chemical differences between them. That, they said, can be settled by looking for other molecules at wavelengths not obscured by dust.

"This result tells us that using centimetre radio wavelengths is necessary to properly study hot corinos," Claudio Codella of Arcetri Astrophysical Observatory in Florence, Italy, said.

"In the future, planned new telescopes such as the next-generation VLA and SKA, will be very important to understanding these objects," added Codella.

Pune, Jul 24: Agile and dexterous, 85-year-old Shantabai Pawar wields sticks with absolute ease as she displays 'lathi-kathi' on the streets of Pune.

A video of her, displaying her skills in the Indian martial art form for livelihood, has gone viral on social media.

Pawar told media persons that she learnt the art form when she was only eight and has been practising it since then. The ancient martial art s believed to be linked to Dombari community, a nomadic tribe in Maharashtra.

"I have been pursuing the art of lathi-kathi since I was eight. I have never left it. It is part of me and it is an honour to practice it. My father taught me this. He taught me to work hard," Pawar told media persons.

In the video, the sari-clad octogenarian takes a warrior-like stride and effortlessly rotates a stick several times in a second in her hand and around her head and then does it with two sticks together with a smile on her face. She also tosses a stick in the air and catches it with ease.

The assembled gathering is impressed and enthused.

"People come and say, 'Well done Daadi!' I practice it to earn money for my children and grandchildren," she said.

Pawar leaves her home in the morning in the conditions created by coronavirus and performs the art form on roads and streets.

"I go to various areas to perform the art form and people give money," she said.

The artiste also uses thali and stick to gather the attention of people as most of them are indoors due to conditions created by COVID-19.

Senior citizens have been advised against venturing out due to their greater susceptibility to coronavirus but Pawar said she is not afraid to step out.

"People do advise me to not go out due to fear of COVID-19 but I am not scared. Whenever I step out, I pray to my God and he has kept me safe so far," she said.

Aishwarya Kale, a dancer and the person who uploaded the video on social media, said that it is "only an artist who can understand what help another artist needs".

"I was in that area shopping for some items and it was then I saw her performing and thought that I should film her and upload her video on social media. But I never thought that the video would go viral and she would receive financial help not just from people in the country but overseas as well," Kale told media persons.

"She is now getting honour for her craft that she couldn't get in the last 85 years. I feel good that through my small video, her art form has become viral," she added.