Ground-based discovery of two strongly interacting exoplanets

Agencies
July 2, 2020

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.

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Agencies
March 8,2020

New Delhi, Mar 8: In order to spread awareness, a special COVID-19 mobile phone caller tune was launched by all telecom operators with basic infection prevention messages played when a caller dials-out, Ministry of Health and Family Welfare said on Saturday.

"In order to spread awareness about COVID-19, a special COVID-19 mobile phone caller tune was launched by all telecom operators. Over 117.2 crore subscribers of BSNL, MTNL Reliance Jio, Airtel and Vodafone-Idea are being progressively reached out to through SMSs and Call Backs," Ministry of Health and Family Welfare said in a press statement.

"As many as 52 laboratories are now operational across the country for testing the COVID-19 virus. An additional 57 laboratories have been provided with Viral Transport Media and swabs for sample collection," the statement added.

India has 39 confirmed cases of deadly coronavirus so far. The disease has caused deaths of 3200 people globally. 

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Agencies
July 2,2020

Leiden, Jul 2: Astronomers have discovered a luminous galaxy caught in the act of reionizing its surrounding gas only 800 million years after the Big Bang.

The research, led by Romain Meyer, PhD student at UCL in London, UK, has been presented at the virtual annual meeting of the European Astronomical Society (EAS).

Studying the first galaxies that formed 13 billion years ago is essential to understanding our cosmic origins. One of the current hot topics in extragalactic astronomy is 'cosmic reionization,' the process in which the intergalactic gas was ionized (atoms stripped of their electrons).

Cosmic reionization is similar to an unsolved murder: We have clear evidence for it, but who did it, how and when? We now have strong evidence that hydrogen reionization was completed about 13 billion years ago, in the first billion years of the universe, with bubbles of ionized gas slowly growing and overlapping.

The objects capable of creating such ionized hydrogen bubbles have however remained mysterious until now: the discovery of a luminous galaxy in which 60-100 percent of ionizing photons escape, is likely responsible for ionizing its local bubble. This suggests the case is closer to being solved.

The two main suspects for cosmic reionization are usually 1) a population of numerous faint galaxies leaking ~10 percent of their energetic photons, and 2) an 'oligarchy' of luminous galaxies with a much larger percentage (>50 percent) of photons escaping each galaxy.

In either case, these first galaxies were very different from those today: galaxies in the local universe are very inefficient leakers, with only <2-3 percent of ionizing photons escaping their host. To understand which galaxies governed cosmic reionization, astronomers must measure the so-called escape fractions of galaxies in the reionization era.

The detection of light from excited hydrogen atoms (the so-called Lyman-alpha line) can be used to infer the fraction of escaping photons. On the one hand, such detections are rare because reionization-era galaxies are surrounded by neutral gas which absorbs that signature hydrogen emission.

On the other hand, if this hydrogen signal is detected it represents a 'smoking gun' for a large ionized bubble, meaning we have caught a galaxy reionizing its surroundings. The size of the bubble and the galaxy's luminosity determines whether it is solely responsible for creating this ionized bubble or if unseen accomplices are necessary.

The discovery of a luminous galaxy 800 million years after the Big Bang supports the scenario where an 'oligarchy' of bright leakers emits most of the ionizing photons.

"It is the first time we can point to an object responsible for creating an ionized bubble, without the need for a contribution from unseen galaxies.

Additional observations with the upcoming James Webb Space Telescope will enable us to study further what is likely one of the best suspects for the unsolved case of cosmic reionization," said Meyer.

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Agencies
January 25,2020

New Delhi, Jan 25: The Patiala House court on Saturday started hearing a plea filed by the Nirbhaya convicts that alleged that the Tihar Jail administration have "not presented the papers on time".

The Public Prosecutor informed the court that Tihar Jail authorities have already supplied the relevant documents. He further informed that these are mere delaying tactics adopted by the convicts.

Advocate A.P. Singh, lawyer for three of the four death row convicts in the Nirbhaya gang-rape case had moved an application before the court seeking directions to the Tihar Jail authorities to supply him the relevant documents in order to exercise the remaining legal remedies available with the death row convicts -- Vinay Pawan and Akshay.

The Public Prosecutor also told the court that he spoke to the jail authorities over the phone and a report in this regard will be filed shortly as the jail officials were on their way to the court.

The judge demanded from the convicts lawyer to show what he has filed.

The convicts lawyer, A.P. Singh, said that he received some documents, but has still not been supplied with the personal diary of one of the convict -- Vinay Kumar Sharma and also the medical documents.

Judge then asked the lawyer to wait for until the report arrives form the Tihar Jail.

On this, the convicts lawyer said he was not questioning the intention of the jail. "I know the jail has been changed. It isn't there fault, too," he said.

The Public Prosecutor refuted the allegation saying that the defence counsel was trying to defeat the speed of law.

"We have supplied all the documents to the counsel. We have supplied all the documents except the painting and some other documents. We have nothing apart from that," public prosecutor said.

Singh, in his plea filed before the Patiala House Court sought urgent orders of the court in order to file a mercy petition of Vinay Sharma and in relation to requests for documents for convicts Vinay Sharma, Pawan Kumar Gupta and Akshay Kumar Singh.

He further said that the convicts undertook several steps to obtain relevant information necessary for filing the mercy petitions. In regular interval, the convicts requested the concerned authority to supply documents pertaining to their medical records from 2012 to 2015 and 2019-2020, records of cellular confinement, records of the amount earned in prison through labour, records of educational and reformative activities like Tihar Olympics and Painting, etc.

The Supreme court had recently dismissed the curative petition for the other two convicts -- Vinay Kumar Sharma (26) and Mukesh Singh (32).

The court had recently issued death warrant against the convicts and fixed 6 a.m. on February 1 as the date and time of execution of the death penalty.

The 23-year-old victim in the case was brutally gang raped and tortured on December 16, 2012, which later led to her death. All the six accused were arrested and charged with sexual assault and murder. One of the accused was a minor and appeared before a juvenile justice court, while another accused committed suicide in Tihar Jail.

Four of the convicts were sentenced to death by a trial court in September 2013, and the verdict was confirmed by the Delhi High Court in March 2014 and subsequently upheld by the Supreme Court in May 2017, which also dismissed their review petitions.

A Juvenile involved in the crime was convicted by a juvenile justice board and released from a reformation home after serving a three-year term.

Hearing in a different case, Chief Justice of India S.A. Bobde on Thursday said a condemned person cannot fight the death penalty endlessly and it was important for the capital punishment to reach its finality.

The death penalty, he noted, cannot be questioned at every turn by the convict.

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