Tuesday January 22, 2019
Home Lead Story Astronomers H...

Astronomers Have Found a Cloud Free Planet Outside Our Solar System

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.

0
//
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.
Astronomers during IAU meet, wikimedia commons

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.

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.
Planets and solar system, Pixabay

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.

Also Read: Microsoft Partners With China Based DJI, World’s Largest Drone Company

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)

Next Story

Astronomers Detect Mysterious Radio Wave Far Away From Milky Way

CHIME is composed of four, 100-meter long half-pipe cylinders of metal mesh, which reconstruct images of the sky by processing the radio signals recorded by more than a thousand antennas.

0
Space, astronomers
Part of a 64-dish radio telescope system is seen during an official unveiling ceremony, July 13, 2018, in Carnarvon, South Africa. A Canadian radio telescope has detected repeating radio waves from deep space. VOA

Astronomers in Canada have detected a mysterious volley of radio waves from far outside our galaxy, according to two studies published Wednesday in Nature.

What corner of the universe these powerful waves come from and the forces that produced them remain unknown.

The so-called repeating fast radio bursts were identified during the trial run last summer of a built-for-purpose telescope running at only a fraction of its capacity.

Known by its acronym CHIME, the world’s most powerful radio telescope, spread across an area as big as a football pitch, is poised to detect many more of the enigmatic pulses now that it is fully operational.

“At the end of the year, we may have found 1,000 bursts,” said Deborah Good, a PhD student at the University of British Columbia and one of 50 scientists from five institutions involved in the research.

 

Saraswati, astronomers
Earth is part of the Milky way galaxy. Wikimed

 

High energy bursts

Fast radio bursts (FRBs) flash only for a micro-instant, but can emit as much energy as the sun does in 10,000 years.

Exactly what causes these high-energy surges of long waves at the far end of the electromagnetic spectrum remains the subject of intense debate.

More than 60 bursts have been cataloged since 2007, but only one other, observed in 2012 at the Arecibo Observatory in Puerto Rico, was a repeater.

“FRBs, it seems, are likely generated in dense, turbulent regions of host galaxies,” Shriharsh Tendulkar, a corresponding author for both studies and an astronomer at McGill University, told AFP.

Cosmic convulsions created by the turbulent gas clouds that give rise to stars, or stellar explosions such a supernovae, are both possible incubators.

But consecutive radio bursts are a special case.

Space, Astronomers
The world’s largest single-dish radio telescope at the Arecibo Observatory in Arecibo, Puerto Rico, photographed July 13, 2016. Dwindling funds from the U.S. government and construction of bigger, more powerful telescopes are threatening this telescope’s future. VOA

No little green men

“The fact that the bursts are repeated rules out any cataclysmic models in which the source is destroyed while generating the burst,” Tendulkar added.

“An FRB emitted from a merger of two neutron stars, or a neutron star and a black hole, for example, cannot repeat.”

It is not yet clear whether the breeding grounds of repeating bursts are different from those that produce only a single radio pulse.

Significantly, the 2012 and 2018 “repeaters” have strikingly similar properties.

CHIME (Canadian Hydrogen Intensity Mapping Experiment) also spotted a dozen single burst radio waves, but with an unusual profile.

Most FRBs spotted so far have wavelengths of a few centimeters, but these had intervals of nearly a meter, opening up a whole new line of inquiry for astronomers.

Could these enigmatic radio pulses point to intelligence elsewhere in the Universe? Might they be messages in a bottle?

SpaceX, Astronomers
The night sky is lit up above Vandenberg Air Force Base, California, during the launch of a SpaceX rocket carrying an Argentine Earth-observation satellite. VOA

“It is extremely, extremely unlikely,” Tendulkar said.

“As a scientist I can’t rule it out 100 percent. But intelligent life is not on the minds of any astronomer as a source of these FRBs.”

Constructed in British Columbia, CHIME is composed of four, 100-meter long half-pipe cylinders of metal mesh, which reconstruct images of the sky by processing the radio signals recorded by more than a thousand antennas.

Also Read: Astronauts Would Be Able to Grow Beans in Space in 2021: NASA

“This signal processing system is the largest of any telescope on Earth,” the researchers said in a communique.

The other institutions with leading roles are the University of Toronto, the National Research Council of Canada, and the Perimeter Institute. (VOA)