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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Have sanctioned 1,000 buses for next fiscal, says K'taka Transport Minister Ramalinga Reddy
Bengaluru (PTI): Karnataka Transport Minister Ramalinga Reddy on Wednesday said the government has sanctioned procurement of 1,000 government buses in the next year’s budget.
According to him, in the current fiscal, 2,000 buses were sanctioned and many of them have already arrived.
Speaking in the Legislative Council, he alleged that the previous BJP government neither bought a single bus nor recruitment was done in the state transport department.
He was replying to BJP MLC Y M Satish’s request for buses for Ballari and Vijayanagara districts.
“From 2019 to 2023, not a single bus was purchased in the four corporations. Not even one bus. If buses are not purchased continuously for four years, what will happen to the organisation?” Reddy asked.
He recalled that the last time buses were procured and recruitments took place were in 2016, when he was the transport minister during the previous Congress government from 2013 to 2018.
“After we came to power (from 2013), we procured 6,080 new buses. Then last year, 2,000 buses were provided, and many of them have already arrived. This year too, 1,000 buses have been sanctioned in the budget,” Reddy told the House.
He noted that 9,000 people were recruited and 1,300 people were appointed on compassionate grounds during the Congress tenure.
The Minister added that around 2,000 to 2,500 buses have been refurbished.
“In total, 6,080 buses came in two years. Last year’s 2,000 buses, and now 1,000 more. Altogether, we have about 26,000 buses. Out of these, nearly one-third have been added in the last two-and-a-half years,” Reddy said.
Satish told the Minister that at least 100 red buses and about 20 Volvo buses are required for Ballari and Vijayanagara districts.
In response, Reddy said in 2022-23, 720 buses were given, and in 2024–25, 307 buses; in 2026, 140 buses—totalling 1,173 new buses were given to Kalyana Karnataka region.
There are around 4,000-odd buses in Kalyana Karnataka region, he said adding that another 400 buses have been tendered and funds have to be released.
“Additionally, 56 high-end buses—sleeper AC, non-sleeper AC, and Volvo buses—are also coming. Now, 400 buses are coming. Priority will be given to Ballari and Vijayanagara districts,” Reddy said.
