Nav: Home

The return of the comet-like exoplanet

September 14, 2017

Astronomers from the University of Geneva (UNIGE), Switzerland, also members of the PlanetS National Centre of Competence in Research, have been working on a joint project with the universities of Berne, Warwick, Grenoble Alpes and the Paris Institute of Astrophysics. The research team focused the Hubble Space Telescope on an exoplanet that had already been seen losing its atmosphere, which forms an enormous cloud of hydrogen, giving the planet the appearance of a giant comet. During earlier observations in 2015, it was not possible to cover the whole cloud, whose shape was predicted by numerical simulations. Thanks to these new observations, however, the scientists have finally been able to confirm the initial predictions. The results are unveiled in the journal Astronomy & Astrophysics.

Exoplanet GJ 436b is similar in size to Neptune (i.e. about four times larger than the Earth). Seen through ultraviolet (UV) glasses, it reveals a huge, Rapunzel-like hair made of gas. This phenomenon, detected in 2015 by astronomers from UNIGE's Faculty of Sciences Observatory, could be due to the planet proximity to its host star: it takes the planet no more than three days to circle around it. The planet loses a part of its hydrogen-rich atmosphere because of the intense stellar irradiation. The lost atmosphere remains for some time around the planet in the form of a huge cloud of gas, which absorbs UV radiation from the star. This is why the cloud can only be seen with Hubble's UV eye.

"We were flabbergasted by the mere size of the cloud, which our initial observations could not cover in its entirety as it passes in front of the star", explains David Ehrenreich, associate professor at UNIGE and principal investigator of the European Research Council-funded project Four Aces, who obtained the observations. The team extrapolated the initial data with a numerical model, to predict what could be the cloud exact shape. The simulation resulted in a comet-like cloud with a trailing tail stretching over tens of millions of kilometres.

The team headed by Baptiste Lavie, a PlanetS PhD student at UNIGE, directed Hubble at GJ 436b afresh. The findings backed up the researchers' predictions in every respect: "I was getting grey hair from analysing the new observations," says Lavie. "So it was hugely satisfying to see that the panache of hydrogen escaping from the planet was really there, in line with the predictions, because now we understand how it is formed."

The data injected into the numerical model explained the observations accurately: "We even took into account the pressure that the light from the star exerts on the hydrogen atoms that escape from the planet!" says Vincent Bourrier, the UNIGE astronomer who developed the digital model.

Solving the mystery of this rare phenomenon means the researchers are now in a position to understand how it affects other exoplanets, some receiving even more irradiation than GJ 436b. "We're expecting some more surprises," says Lavie with a smile.
-end-
PlanetS is a National Centre of Competence in Research (NCCR) backed by the Swiss National Fund for Scientific Research.

FOUR ACES (Future of Upper Atmospheric Characterisation of Exoplanets with Spectroscopy) is a European project funded by the European Research Council's Consolidator grant (ERC Grant No. 724427).

Université de Genève

Related Hydrogen Articles:

Paving the way for hydrogen fuel cells
The hype around hydrogen fuel cells has died down, but scientists have continued to pursue new technologies that could enable such devices to gain a firmer foothold.
Keeping the hydrogen coming
A coating of molybdenum improves the efficiency of catalysts for producing hydrogen.
Hydrogen bonds directly detected for the first time
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope.
Argon is not the 'dope' for metallic hydrogen
Hydrogen is both the simplest and the most-abundant element in the universe, so studying it can teach scientists about the essence of matter.
Metallic hydrogen, once theory, becomes reality
Nearly a century after it was theorized, Harvard scientists have succeeded in creating metallic hydrogen.
From theory to reality: The creation of metallic hydrogen
For more than 80 years, it has been predicted that hydrogen will adopt metallic properties under certain conditions, and now researchers have successfully demonstrated this phenomenon.
Artificial leaf goes more efficient for hydrogen generation
A new study, affiliated with Ulsan National Institute of Science and Technology has introduced a new artificial leaf that generates hydrogen, using the power of the Sun to mimic underwater photosynthesis.
Hydrogen from sunlight -- but as a dark reaction
The storage of photogenerated electric energy and its release on demand are still among the main obstacles in artificial photosynthesis.
New process produces hydrogen at much lower temperature
Waseda University researchers have developed a new method for producing hydrogen, which is fast, irreversible, and takes place at much lower temperature using less energy.
Hydrogen in your pocket? New plastic for carrying and storing hydrogen
A Waseda University research group has developed a polymer which can store hydrogen in a light, compact and flexible sheet, and is safe to touch even when filled with hydrogen gas.

Related Hydrogen Reading:

Hydrogen: The Essential Element
by John S. Rigden (Author)

Seduced by simplicity, physicists find themselves endlessly fascinated by hydrogen, the simplest of atoms. Hydrogen has shocked, it has surprised, it has embarrassed, it has humbled--and again and again it has guided physicists to the edge of new vistas where the promise of basic understanding and momentous insights beckoned. The allure of hydrogen, crucial to life and critical to scientific discovery, is at the center of this book, which tells a story that begins with the big bang and continues to unfold today.

In this biography of hydrogen, John Rigden shows how this singular... View Details


The Magic of Hydrogen Peroxide
by Emily Thacker (Author)

An Ounce of Hydrogen Peroxide is Worth a Pound of Cure Hydrogen peroxide is trusted by every hospital and emergency room in the country for its remarkable ability to kill deadly germs like E. coli and the swine flu virus. In fact, it has attracted so much interest from doctors that over 6000 articles about it have appeared in scientific publications around the world. Research has discovered that hydrogen peroxide enables your immune system to function properly and fight infection and disease. Doctors have found it can shrink tumors and treat allergies, Alzheimer’s, asthma, clogged arteries,... View Details


2014 True Power of Hydrogen Peroxide, Miracle Path To Wellness - Mary Wright, goes beyond One Minute Cure
by Mary Wright (Author)

The 2014 Publication the True Power of Hydrogen Peroxide, Miracle Path To Wellness (Retail $27.95) is an extraordinary book unlike any prior book on the topic of Hydrogen Peroxide therapy and oxygenation. Well documented but also easy to read, the author gives step-by-step instructions and guidelines to personalize your health and wellness protocol specifically for you for internal and extra body health and wellness, plus the many ways to use hydrogen peroxide in your life. It also warns of ways not to use hydrogen peroxide, something you do not find in other books. Yet the book does not stop... View Details


The Hydrogen Sonata (Culture)
by Iain M. Banks (Author)

The New York Times bestselling Culture novel...
The Scavenger species are circling. It is, truly, provably, the End Days for the Gzilt civilization.

An ancient people, organized on military principles and yet almost perversely peaceful, the Gzilt helped set up the Culture ten thousand years earlier and were very nearly one of its founding societies, deciding not to join only at the last moment. Now they've made the collective decision to follow the well-trodden path of millions of other civilizations; they are going to Sublime, elevating themselves to a new and almost... View Details


Hydrogen Peroxide: Medical Miracle
by William Campbell Douglass II (Author)

'Less is more' when it comes to the small molecule hydrogen peroxide - H2O2 - and the role it plays in maintaining health and fighting diseases. Discover how the miraculous healing agent works, why it's a 'natural' and 'bio-identical' substance, and it's multiple medical applications. View Details


Build A Solar Hydrogen Fuel Cell System
by Phillip Hurley (Author)

Learn how to construct and operate the components of a solar hydrogen fuel cell system: the fuel cell stack, the electrolyzer to generate hydrogen fuel, simple hydrogen storage, and solar panels designed specifically to run electrolyzers for hydrogen production. Complete, clear, illustrated instructions to build all the major components make it easy for the non-engineer to understand and work with this important new technology.

Featured are the author's innovative and practical designs for efficient solar powered hydrogen production including:

ESPMs (Electrolyzer Specific... View Details


Dark Sun: The Making of the Hydrogen Bomb
by Richard Rhodes (Author)

Here, for the first time, in a brilliant, panoramic portrait by the Pulitzer Prize-winning author of The Making of the Atomic Bomb, is the definitive, often shocking story of the politics and the science behind the development of the hydrogen bomb and the birth of the Cold War.

Based on secret files in the United States and the former Soviet Union, this monumental work of history discloses how and why the United States decided to create the bomb that would dominate world politics for more than forty years. View Details


Hydrogen Peroxide Miracles & Cures Handbook: Benefits, Uses & Medical Therapy with Hydrogen Peroxide
by Greg Cook (Author)

The ULTIMATE Guide To Hydrogen Peroxide - Everything You Need To Know! Are You Ready To Improve Your Life With Hydrogen Peroxide? If So You've Come To The Right Place... * * *LIMITED TIME OFFER! 50% OFF!* * * Hydrogen peroxide, whose chemical formula is H2O2, is a popular disinfectant commonly used in clinics and hospitals. Clinical personnel use it to cleanse and disinfect wounds. However, there is more to H2O2 than just its popular use. In this book, you’ll learn more about this chemical compound and how it can change your life! Here's A Preview Of What You'll Learn... ... View Details


Solar Hydrogen Generation: Transition Metal Oxides in Water Photoelectrolysis
by Jinghua Guo (Author), Xiaobo Chen (Author)

State-of-the-art renewable energy science research and applications

Solar Hydrogen Generation: Transition Metal Oxides in Water Photoelectrolysis provides expert techniques for extracting hydrogen from water using transition metal oxides as catalysts. The basic processes of electrochemistry and photocatalysis for hydrogen production are described along with photocatalytic reactions and semiconductor photocatalysts, particularly metal oxides.

This in-depth guide illustrates the corresponding crystal structure vs. electronic structure and optical properties vs. light absorption... View Details


Hydrogen Peroxide and Aloe Vera Plus Other Home Remedies
by Conrad LeBeau (Author), Conrad LeBeau (Editor)

Home remedies using hydrogen peroxide, testimonials, case reports and clinical research on preventing and treating over 50 health conditions. Discusses the use of hydrogen peroxide, ozone, castor oil, raw honey, aloe vera, blackstrap molasses, coral calcium, grapefruit seeds, limewater, milk of magnesia, birch water, flaxseed oil, brazil nuts, garlic, oregano, cayenne, wakame and lemons. Includes low cost, non-toxic treatment options for cancer and a chapter on 10 ways to treat infections at home. View Details

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Simple Solutions
Sometimes, the best solutions to complex problems are simple. But simple doesn't always mean easy. This hour, TED speakers describe the innovation and hard work that goes into achieving simplicity. Guests include designer Mileha Soneji, chef Sam Kass, sleep researcher Wendy Troxel, public health advocate Myriam Sidibe, and engineer Amos Winter.
Now Playing: Science for the People

#448 Pavlov (Rebroadcast)
This week, we're learning about the life and work of a groundbreaking physiologist whose work on learning and instinct is familiar worldwide, and almost universally misunderstood. We'll spend the hour with Daniel Todes, Ph.D, Professor of History of Medicine at The Johns Hopkins University, discussing his book "Ivan Pavlov: A Russian Life in Science."