Astronomers find exoplanet with cloud-free atmosphere
London, May 8: Astronomers have found that a planet outside our solar system, which is similar to Saturn in mass and exceeds the size of Jupiter by 20 per cent, has an atmosphere free of clouds.
The hot gas giant, WASP-96b, periodically transits a Sun-like star 980 light years away in the southern constellation Phoenix.
Using the the European Southern Observatory's Very Large Telescope in Chile, the team studied the atmosphere of WASP-96b when the planet passed in front of its host-star.
This enabled the team to measure the decrease of starlight caused by the planet and its atmosphere, and thereby determine the planet's atmospheric composition.
"We've been looking at more than twenty exoplanet transit spectra. WASP-96b is the only exoplanet that appears to be entirely cloud-free and shows such a clear sodium signature, making the planet a benchmark for characterisation," said lead author of the study Nikolay Nikolov from University of Exeter in Britain.
Just like an individual's fingerprints are unique, atoms and molecules have a unique spectral characteristic that can be used to detect their presence in celestial objects.
The spectrum of WASP-96b shows the complete fingerprint of sodium, which can only be observed for an atmosphere free of clouds, according to the study published in the journal Nature.
It has long been predicted that sodium exists in the atmospheres of hot gas-giant exoplanets, and in a cloud-free atmosphere it would produce spectra that are similar in shape to the profile of a camping tent.
"Until now, sodium was revealed either as a very narrow peak or found to be completely missing. This is because the characteristic 'tent-shaped' profile can only be produced deep in the atmosphere of the planet and for most planet clouds appear to get in the way," Nikolov added.
Clouds and hazes are known to exist in some of the hottest and coldest solar system planets and exoplanets.
The presence or absence of clouds and their ability to block light plays an important role in the overall energy budget of planetary atmospheres.
"It is difficult to predict which of these hot atmospheres will have thick clouds. By seeing the full range of possible atmospheres, from very cloudy to nearly cloud-free like WASP-96b, we'll gain a better understanding of what these clouds are made of," explains study co-author Jonathan Fortney, Professor at University of California, Santa Cruz (UCSC), US.
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Close kin of judges for HC judgeship: SC collegium may consider idea against it
New Delhi, Dec 30: The Supreme Court collegium may consider an idea against the appointment of close kin of judges in high courts, sources said.
The proposal was said to be mooted by a senior judge, and if acted upon, could bring more inclusivity in such appointments and erase the perception of lineage outweighing merit in judicial appointments.
According to sources, the collegium could consider the idea of instructing high court collegiums to refrain from recommending candidates whose parents or close relatives were current or former Supreme Court or high court judges.
While this proposal may disqualify some deserving candidates, one of the sources believed it would open up opportunities for first-generation lawyers and broaden the representation of diverse communities in constitutional courts.
However, this may lead to unjust denial of judgeship to deserving people just because they are related to sitting or former judges of the higher judiciary, added the source.
The three-member collegium, which recommends names for the judgeship in the apex court at the moment, comprises Chief Justice of India Sanjiv Khanna and Justices B R Gavai and Surya Kant.
Justices Hrishikesh Roy and Abhay S Oka are also part of the larger five-member SC collegium that decides and recommends names for judgeship in high courts.
The apex court collegium recently started personal interactions with lawyers and judicial officers recommended for elevation in the high courts, marking a significant leap from the traditional biodata, written assessments and intelligence reports.
The SC collegium held its meetings on December 22 and recommended about six names to the Centre for appointment as judges in high courts at Rajasthan, Uttarakhand, Bombay and Allahabad.
The need to reintroduce personal interactions seems to have gathered steam after a recent controversy involving Justice Shekhar Kumar Yadav of the Allahabad High Court.
Justice Yadav’s contentious remarks at a VHP event in December, when he called for India to function according to the majority’s wishes, had sparked widespread criticism.
Justice Yadav appeared before the Supreme Court collegium on December 17 to put forth his version on the controversy.
The top court on December 10 took note of news reports over the statements and sought a report from the Allahabad High Court on the issue.
"The Supreme Court has taken note of newspaper reports of a speech given by Mr Justice Shekhar Kumar Yadav, a sitting judge of the High Court of Judicature at Allahabad. The details and particulars have been called from the high court and the matter is under consideration," an official statement said earlier.
According to the established norm, a judge, against whom a report is sought by the apex court collegium on any controversial issue from the high court concerned, is given opportunity to put forth his or her version before the top court collegium headed by the chief justice of India.
