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Prof. Tariq Mansoor is presently serving as the Vice-Chancellor, Aligarh Muslim University, Aligarh. Previously he has also served as Principal, J.N. Medical College, Chief Medical Superintendent, J.N. Medical College Hospital and Chairman, Department of Surgery. He is also the member of Medical Council of India since March 2015 for a period of four years. He is product of the first batch of prestigious Our Lady of Fatima Higher Secondary School, Aligarh. During his school days he has served as House Captain as well as School Captain. He did his MBBS and MS in General Surgery from Jawaharlal Nehru Medical College, AMU, Aligarh. A surgeon by profession with special interest in Breast and Thyroid Diseases, Prof. Tariq Mansoor has 33 years of Teaching and 35 years of Clinical experience. He has 90 publications to his credit and has guided 49 Postgraduate Medical Students for their Thesis as Supervisor / Co-Supervisor

Astronomers find exoplanet with cloud-free atmosphere

Astronomers find exoplanet with cloud-free atmosphere

London: 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.

IANS

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from The Siasat Daily

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